WO2013042410A1 - Fluoroscopic processing device, fluoroscopy device, fluoroscopy system, fluoroscopy method, and fluoroscopy program - Google Patents

Fluoroscopic processing device, fluoroscopy device, fluoroscopy system, fluoroscopy method, and fluoroscopy program Download PDF

Info

Publication number
WO2013042410A1
WO2013042410A1 PCT/JP2012/065617 JP2012065617W WO2013042410A1 WO 2013042410 A1 WO2013042410 A1 WO 2013042410A1 JP 2012065617 W JP2012065617 W JP 2012065617W WO 2013042410 A1 WO2013042410 A1 WO 2013042410A1
Authority
WO
WIPO (PCT)
Prior art keywords
radiation
gradation signal
interest
region
unit
Prior art date
Application number
PCT/JP2012/065617
Other languages
French (fr)
Japanese (ja)
Inventor
大田　恭義
北野　浩一
西納　直行
岩切　直人
中津川　晴康
Original Assignee
富士フイルム株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 富士フイルム株式会社 filed Critical 富士フイルム株式会社
Publication of WO2013042410A1 publication Critical patent/WO2013042410A1/en

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/42—Arrangements for detecting radiation specially adapted for radiation diagnosis
    • A61B6/4208—Arrangements for detecting radiation specially adapted for radiation diagnosis characterised by using a particular type of detector
    • A61B6/4233—Arrangements for detecting radiation specially adapted for radiation diagnosis characterised by using a particular type of detector using matrix detectors
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/44—Constructional features of apparatus for radiation diagnosis
    • A61B6/4429—Constructional features of apparatus for radiation diagnosis related to the mounting of source units and detector units
    • A61B6/4464—Constructional features of apparatus for radiation diagnosis related to the mounting of source units and detector units the source unit or the detector unit being mounted to ceiling
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/46—Arrangements for interfacing with the operator or the patient
    • A61B6/461—Displaying means of special interest
    • A61B6/463—Displaying means of special interest characterised by displaying multiple images or images and diagnostic data on one display
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/48—Diagnostic techniques
    • A61B6/486—Diagnostic techniques involving generating temporal series of image data
    • A61B6/487—Diagnostic techniques involving generating temporal series of image data involving fluoroscopy
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/54—Control of apparatus or devices for radiation diagnosis
    • A61B6/542—Control of apparatus or devices for radiation diagnosis involving control of exposure

Definitions

  • the present invention relates to a radiation moving image photographing processing apparatus, a radiation moving image photographing apparatus, a radiation moving image photographing system, a radiation moving image photographing method, and a radiation moving image photographing program.
  • a radiation sensitive layer is disposed on a TFT (Thin Film Transistor) active matrix substrate, and a radiation detector ("Electronic cassette” or the like) such as FPD (Flat Panel Detector) capable of converting a radiation dose into digital data (electric signal)
  • a radiation image capturing apparatus for capturing a radiation image represented by an irradiated radiation dose using this radiation detector has been put to practical use.
  • the radiation dose is, for example, compatiblely converted to the light emission amount, and then there is an indirect conversion method in which it is converted into an electrical signal, and a direct conversion method in which a radiation dose is directly converted into an electrical signal. Will be adopted.
  • a so-called moving image is displayed by continuously reproducing the image information detected by the radiation detector at predetermined time intervals.
  • the amount of data increases as compared to still pictures. Therefore, the technique of shortening the data transfer time by using the technique of JP-A-2007-97977 is an effective technique.
  • feedback control (ABC “Auto Brightness Control” control) is performed to control the radiation dose based on the captured image information to optimally maintain the detection state by the radiation detector. It is also essential for shooting.
  • the ROI is narrower than that of a still image and the area at which the user is gazing is also narrow. Therefore, if the brightness of the entire image fluctuates to a large or small part by ABC control, the flicker of the displayed image It may cause tiredness of the user's eyes.
  • the flickering of images at the time of moving image shooting and ABC control is not taken into consideration.
  • the present invention has been made in consideration of the above facts, and is capable of suppressing flickering of an image by ABC control of a moving image and reducing eye fatigue, a radiation moving image capturing apparatus, a radiation moving image, Provided are an imaging system, a radiation moving image capturing method, and a radiation moving image capturing program.
  • the radiation moving image processing apparatus is configured to transmit a plurality of radiation doses that have been emitted from the radiation irradiating unit that irradiates radiation with radiation irradiation energy according to the set value that has been set. And a still image of one frame based on the gradation signal output from the radiation image capturing unit that outputs a digital gradation signal according to the radiation amount received for each of the pixels.
  • An image information generation unit that generates information and generates moving image information by combining a plurality of frames of the still image information continuously, and a part of the image indicated by the moving image information generated by the image information generation unit
  • the region of interest setting unit sets the region of interest as the region of interest, and the operation value of the gradation signal in a part of the still image information of at least one frame is determined in advance based on the
  • the control unit performs feedback control of the setting value of the radiation energy irradiated from the radiation irradiating unit at a predetermined control cycle, and the change degree of the gradation signal by the feedback control of the control unit is
  • An adjusting unit configured to adjust the gray scale signal corresponding to the non-interest region such that the non-interest region other than the interest region is smaller than the region of interest set by the region-of-interest setting unit.
  • the radiation irradiation unit irradiates radiation with radiation irradiation energy according to the set value set, and the radiation image capturing unit irradiates radiation from the radiation irradiation unit
  • the radiation amount which has passed through the subject is then irradiated to the radiation detector. Further, in the radiation detector, when the radiation is irradiated, a digital gradation signal according to the radiation amount received for each pixel is output.
  • still image information of one frame is generated based on the gradation signal output from the radiation image capturing unit, and moving image information is generated by continuously combining a plurality of still image information.
  • region-of-interest setting unit a part of the image indicated by the moving image information generated by the image information generation unit is set as the region of interest.
  • the radiation irradiated from the radiation irradiating unit such that the operation value of the gradation signal in a part of at least one frame of the still image information becomes a value in a predetermined range based on the gradation signal.
  • the set value of energy is feedback controlled in a predetermined control cycle (ABC control).
  • ABSC control a predetermined control cycle
  • the operation value of the gray level signal may be an average value of the gray level signals of the region of interest. It may be a value based on it, or another calculated value may be applied.
  • the image is flickered by feedback control by the control unit.
  • the flicker of the image also increases, leading to eye fatigue.
  • the adjustment unit acquires pixels of the non-interest region so that the change degree of the gradation signal by feedback control of the control unit is smaller in the non-interest region than in the interest region set by the region-of-interest setting unit. Tone signal is adjusted. That is, in the non-interest region, since the degree of change of the gradation signal is smaller than that in the region of interest, the flickering of the image is also reduced. Therefore, it is possible to suppress the flicker of the image by the ABC control in the case of the moving image, and to alleviate the tiredness of the user's eyes.
  • the gradation signal is a digital signal of N (N is a natural number of 2 or more) bits
  • the adjustment unit is The low-order n (n ⁇ N natural number) bit signal of the N bits may be adjusted to a predetermined value.
  • the adjustment unit may adjust the value to “0” or “1” as the predetermined value. This makes it possible to make the degree of change of the gradation signal in the non-interest region smaller than the interest region.
  • the adjustment unit is configured to acquire the gradation signal as the pixel of the non-interest image in the (N-1) frame.
  • a gradation signal may be applied to adjust the time constant of the non-interest region to be later than the interest region. As described above, even if the gradation signal adjustment is performed, it is possible to make the degree of change of the gradation signal in the non-interest region smaller than the region of interest.
  • the adjustment unit controls the gradation signal acquired as a pixel of the non-interest region by the control unit. It may be adjusted to be held constant until the end. As described above, even if the gradation signal is adjusted, it is possible to make the degree of change of the gradation signal in the non-interest region smaller than that in the region of interest.
  • the adjustment unit is configured to adjust the gray level signal of the non-interest region more than the change period of the gray level signal of the region of interest.
  • the gradation signal may be adjusted so that the change period is delayed. As described above, even if the gradation signal is adjusted, it is possible to make the degree of change of the gradation signal in the non-interest region smaller than that in the region of interest.
  • a plurality of pixels are provided with a radiation dose that has been applied from the radiation irradiating unit that irradiates radiation with radiation irradiation energy according to the set value that has been set, and has passed through the subject.
  • a radiation image processing unit which receives a radiation detector and outputs a digital gradation signal according to the radiation amount received for each pixel, and a radiation moving image processing apparatus according to any one of the first to seventh aspects of the present invention; It is good also as a radiographic animation imaging device provided with.
  • a radiation irradiator for emitting radiation with radiation irradiation energy according to the set value set, and a radiation moving image photographing apparatus according to the eighth aspect of the present invention. It may be a radiation video imaging system.
  • the radiation moving image photographing method radiation is irradiated from the radiation irradiating unit toward the subject with radiation energy according to the set value set, and radiation passing through the subject
  • the amount is received by a radiation detector having a plurality of pixels, and one frame of still image information is generated based on a digital gradation signal according to the radiation amount received for each pixel, and the still image information Are sequentially combined to generate moving image information, and a part of the image indicated by the generated moving image information is set as a region of interest, and the still image of at least one frame is set based on the gradation signal.
  • the control unit of the control unit that performs feedback control of the setting value of the radiation energy at a predetermined control cycle such that the operation value of the gradation signal in part of the information becomes a value within a predetermined range.
  • the gradation signal corresponding to the non-interest region is adjusted such that the change degree of the gradation signal due to feedback control is smaller in the non-interest region other than the interest region than the set region of interest .
  • radiation is irradiated toward the subject with radiation energy corresponding to the set value set, and a radiation dose that has passed through the subject is determined by a plurality of pixels. Received by the equipped radiation detector.
  • still image information of one frame is generated based on a digital gradation signal according to the radiation amount received for each pixel of the radiation detector, and a plurality of frames of the still image information are continuously combined to form a moving image Information is generated, and a part of the image indicated by the generated moving image information is set as a region of interest.
  • the gradation signal acquired as the pixel of the non-interest region is adjusted so that the change degree of the gradation signal by the feedback control of the control unit becomes smaller in the non-interest region than the set interest region. That is, in the non-interest region, since the degree of change of the gradation signal is smaller than that in the region of interest, the flickering of the image is also reduced. Therefore, it is possible to suppress the flicker of the image by the ABC control in the case of the moving image, and to alleviate the tiredness of the user's eyes.
  • the calculation value of the gradation signal may be an average value of the gradation signal of the region of interest, or an addition including weighting may be performed. It may be a value based on it, or another calculated value may be applied.
  • the gradation signal is a digital signal of N (N is a natural number of 2 or more) bits, and the non-interest region
  • the signal of the lower n (n ⁇ N natural number) bits of the N bits of the gradation signal acquired as the pixel of (1) may be adjusted to a predetermined value.
  • the predetermined value may be adjusted to “0” or “1”. This makes it possible to make the degree of change of the gradation signal in the non-interest region smaller than the interest region.
  • the gradation signal of the (N-1) frame is applied as the gradation signal acquired as a pixel of the non-interest image Then, the time constant of the non-interest region may be adjusted to be later than the interest region. As described above, even if the gradation signal adjustment is performed, it is possible to make the degree of change of the gradation signal in the non-interest region smaller than the region of interest.
  • the gradation signal acquired as a pixel of the non-interest region is held constant until the feedback control is completed. It may be adjusted as follows. As described above, even if the gradation signal is adjusted, it is possible to make the degree of change of the gradation signal in the non-interest region smaller than that in the region of interest.
  • the change period of the gradation signal of the non-interest region is later than the change period of the gradation signal of the region of interest.
  • the gradation signal may be adjusted as described above. As described above, even if the gradation signal is adjusted, it is possible to make the degree of change of the gradation signal in the non-interest region smaller than that in the region of interest.
  • a radiation moving image photographing program is for causing a computer to function as each unit constituting a radiation moving image processing apparatus according to any one of the first to seventh aspects of the present invention. .
  • the computer can be made to function as each unit constituting the radiation moving image processing apparatus according to any one of the first to seventh aspects of the present invention.
  • it is possible to reduce the tiredness of the user's eyes by suppressing the flicker of the image due to the ABC control in the case of the moving image.
  • FIG. 1 is a schematic configuration diagram of a radiation information system (hereinafter, referred to as “RIS” (Radiology Information System)) 10 according to the present embodiment.
  • This RIS 10 is capable of shooting moving images in addition to still images.
  • the definition of a moving image means that still images are displayed one after another at high speed and recognized as a moving image, and the still images are photographed, converted into electric signals, and transmitted to reproduce the still images from the electric signals. The process is repeated at high speed. Therefore, depending on the degree of "high speed”, so-called “frame feed”, in which the same area (part or all) is photographed a plurality of times within a predetermined time and continuously reproduced, is also included in the moving image I assume.
  • the RIS 10 is a system for managing information such as medical treatment reservations and diagnostic records in the radiology department, and constitutes a part of a hospital information system (hereinafter referred to as "HIS" (Hospital Information System)).
  • HIS Hospital Information System
  • the RIS 10 includes a plurality of radiographing systems (hereinafter referred to as "terminals") 12, a RIS server 14, and a plurality of radiographing systems individually installed in radiography rooms (or operating rooms) in a hospital.
  • imaging system. a radiographing system
  • imaging system. 16 which are respectively connected to an in-hospital network 18 composed of a wired or wireless LAN (Local Area Network) or the like.
  • the HIS server (illustration omitted) which manages the whole HIS is connected to the network 18 in a hospital.
  • the radiation imaging system 16 may be a single or three or more facilities. In FIG. 1, although it is installed for each imaging room, two or more radiation images are taken in a single imaging room The imaging system 16 may be arranged.
  • the terminal device 12 is used by a doctor or a radiographer to input diagnostic information and facility reservation, to view, and the like. Radiographic image radiographing requests and radiographing reservations are made via the terminal device 12.
  • Each terminal device 12 is configured to include a personal computer having a display device, and can communicate with each other via the RIS server 14 and the hospital network 18.
  • the RIS server 14 receives an imaging request from each of the terminal devices 12, manages the imaging schedule of radiation images in the imaging system 16, and includes a database 14A.
  • the database 14A was photographed in the patient's (subject's) attribute information (name, gender, date of birth, age, blood type, body weight, patient ID (Identification) etc.) as a subject, medical history, history of medical examination, in the past Information on the patient such as a radiation image, information on the electronic cassette 20 such as identification number (ID information) of the electronic cassette 20 described later, type, size, sensitivity, date of start of use, number of times of use, etc.
  • ID information identification number of the electronic cassette 20 described later, type, size, sensitivity, date of start of use, number of times of use, etc.
  • the imaging system 16 captures a radiation image by the operation of a doctor or a radiologist in accordance with an instruction from the RIS server 14.
  • the imaging system 16 is a radiation generating apparatus that irradiates the subject with the radiation X, which is a dose according to the irradiation conditions, from the radiation irradiation source 22A that irradiates the radiation X under the control of the radiation irradiation control unit 22 (see FIG. 4) 24 and radiation detector 26 (see FIG. 3) that generates radiation by absorbing radiation X transmitted through the region to be imaged of the subject, and generates image information indicating a radiation image based on the generated charge amount.
  • the electronic cassette 20 is provided, a cradle 28 for charging a battery incorporated in the electronic cassette 20, and a console 30 for controlling the electronic cassette 20 and the radiation generator 24.
  • the console 30 acquires various types of information included in the database 14A from the RIS server 14 and stores the information in the HDD 88 (see FIG. 4) described later, using the information as necessary to set the electronic cassette 20 and the radiation generator 24. Control the
  • FIG. 2 shows an example of the arrangement of the devices in the radiation imaging room 32 of the imaging system 16 according to the present embodiment.
  • the radiography room 32 there are a standing table 34 used when performing radiation imaging in a standing position, and a holding platform 36 used when performing radiation imaging in a prone position.
  • the space in front of the standing stand 34 is taken as the imaging position of the subject 38 at the time of radiographing in a standing position, and the space above the lying stand 36 is when radiographing in a lying position.
  • the shooting position of the test subject 40 is
  • the stand 34 is provided with a holder 42 for holding the electronic cassette 20, and the electronic cassette 20 is held by the holder 42 when a radiation image is taken in the standing position.
  • a holding unit 44 for holding the electronic cassette 20 is provided on the holding base 36, and the electronic cassette 20 is held by the holding unit 44 when the radiation image is taken in the lying position.
  • the radiation irradiation source 22A is turned around a horizontal axis so that radiography in a standing position and radiography in a recumbent position are also possible by radiation from a single radiation irradiation source 22A.
  • a drive source for moving (including rotating) the radiation irradiation source 22A in the directions of arrows A to C in FIG. 2 is incorporated in the support moving mechanism 46, and is not shown here.
  • the cradle 28 is formed with a housing portion 28A capable of housing the electronic cassette 20.
  • the battery contained in the housing 28A of the cradle 28 is charged, and when taking a radiation image, the electronic cassette 20 is taken out of the cradle 28 by a radiologist etc. If the photographing position is the recumbent position, the image is held by the holding portion 44 of the holding base 36.
  • various types of information are communicated by wireless communication between the radiation generating device 24 and the console 30 and between the electronic cassette 20 and the console 30. Send and receive (details will be described later).
  • the electronic cassette 20 is not used only in a state of being held by the holding portion 42 of the standing base 34 and the holding portion 44 of the recumbent base 36, but from the viewpoint of its portability, the arms, legs, etc. When taking a picture, it can be used in a state where it is not held by the holding unit.
  • FIG. 3 is a schematic cross-sectional view schematically showing the configuration of three pixel portions of the radiation detector 26 provided in the electronic cassette 20. As shown in FIG.
  • the signal output unit 52, the sensor unit 54 (the TFT substrate 74), and the scintillator 56 are sequentially stacked on the insulating substrate 50.
  • the sensor unit 54 constitutes a pixel group of the TFT substrate 74. That is, the plurality of pixels are arranged in a matrix on the substrate 50, and the signal output unit 52 and the sensor unit 54 in each pixel are configured to have an overlap.
  • An insulating film 53 is interposed between the signal output unit 52 and the sensor unit 54.
  • the scintillator 56 is formed on the sensor unit 54 via the transparent insulating film 58, and forms a film of a phosphor which converts radiation incident from the upper side (the opposite side of the substrate 50) or the lower side into light and emits light. It is By providing such a scintillator 56, the radiation transmitted through the subject is absorbed and emitted.
  • the wavelength range of light emitted by the scintillator 56 is preferably a visible light range (wavelength 360 nm to 830 nm), and in order to enable monochrome imaging by this radiation detector 26, it includes a green wavelength range. Is more preferred.
  • the phosphor used for the scintillator 56 preferably contains cesium iodide (CsI), and the emission spectrum at the time of X-ray irradiation is in the range of 400 nm to 700 nm It is particularly preferred to use CsI (Tl) (cesium iodide to which thallium is added).
  • CsI (Tl) cesium iodide to which thallium is added.
  • the emission peak wavelength of CsI (Tl) in the visible light range is 565 nm.
  • the sensor unit 54 includes an upper electrode 60, a lower electrode 62, and a photoelectric conversion film 64 disposed between the upper and lower electrodes.
  • the photoelectric conversion film 64 is made of an organic photoelectric conversion material that absorbs light emitted by the scintillator 56 to generate charges.
  • the upper electrode 60 is preferably made of a conductive material that is transparent to at least the light emission wavelength of the scintillator 56 because the light generated by the scintillator 56 needs to be incident on the photoelectric conversion film 64, specifically, It is preferable to use a transparent conductive oxide (TCO) having a high transmittance to visible light and a small resistance value. Although a metal thin film of Au or the like can be used as the upper electrode 60, TCO is preferable because the resistance value tends to increase if it is desired to obtain a transmittance of 90% or more.
  • TCO transparent conductive oxide
  • the upper electrode 60 may be configured as a single sheet common to all the pixels, or may be divided for each pixel.
  • the photoelectric conversion film 64 contains an organic photoelectric conversion material, absorbs light emitted from the scintillator 56, and generates a charge according to the absorbed light.
  • the photoelectric conversion film 64 containing the organic photoelectric conversion material has a sharp absorption spectrum in the visible region, and electromagnetic waves other than the light emitted by the scintillator 56 are hardly absorbed by the photoelectric conversion film 64, and X-rays The noise generated by the absorption of radiation such as by the photoelectric conversion film 64 can be effectively suppressed.
  • the absorption peak wavelength of the organic photoelectric conversion material forming the photoelectric conversion film 64 be closer to the emission peak wavelength of the scintillator 56 in order to absorb the light emitted by the scintillator 56 most efficiently.
  • the absorption peak wavelength of the organic photoelectric conversion material matches the emission peak wavelength of the scintillator 56, but if the difference between the two is small, it is possible to sufficiently absorb the light emitted from the scintillator 56.
  • the difference between the absorption peak wavelength of the organic photoelectric conversion material and the emission peak wavelength of radiation of the scintillator 56 is preferably 10 nm or less, and more preferably 5 nm or less.
  • a quinacridone organic compound and a phthalocyanine organic compound are mentioned, for example.
  • the difference between the peak wavelengths can be made within 5 nm by using quinacridone as the organic photoelectric conversion material and CsI (Tl) as the material of the scintillator 56
  • the amount of charge generated in the photoelectric conversion film 64 can be substantially maximized.
  • the sensor unit 54 constituting each pixel may include at least the lower electrode 62, the photoelectric conversion film 64, and the upper electrode 60. However, in order to suppress an increase in dark current, the electron blocking film 66 and the hole blocking film It is preferable to provide at least one of 68, and it is more preferable to provide both.
  • the electron blocking film 66 can be provided between the lower electrode 62 and the photoelectric conversion film 64, and when a bias voltage is applied between the lower electrode 62 and the upper electrode 60, the electrons from the lower electrode 62 to the photoelectric conversion film 64 Can be suppressed to increase the dark current.
  • an electron donating organic material can be used for the electron blocking film 66.
  • the hole blocking film 68 can be provided between the photoelectric conversion film 64 and the upper electrode 60, and when a bias voltage is applied between the lower electrode 62 and the upper electrode 60, the upper electrode 60 to the photoelectric conversion film 64. It is possible to suppress an increase in dark current due to the injection of holes.
  • an electron accepting organic material can be used for the hole blocking film 68.
  • the signal output unit 52 corresponds to the lower electrode 62, a capacitor 70 for storing the charge transferred to the lower electrode 62, and a field effect thin film transistor (Thin for converting the charge stored in the capacitor 70 into an electric signal and outputting it.
  • the film transistor may be simply referred to as a thin film transistor) 72 is formed.
  • the region where the capacitor 70 and the thin film transistor 72 are formed has a portion overlapping the lower electrode 62 in a plan view, and with such a configuration, the signal output portion 52 and the sensor portion 54 in each pixel are thick. It will have an overlap in the longitudinal direction. In order to minimize the planar area of the radiation detector 26 (pixel), it is desirable that the region in which the capacitor 70 and the thin film transistor 72 are formed be completely covered by the lower electrode 62.
  • FIG. 4 is a control block diagram of the imaging system 16 according to the present embodiment.
  • the console 30 is configured as a server computer, and includes an operation menu and a display 80 for displaying a captured radiation image and the like, and a plurality of keys, and an operation panel on which various information and operation instructions are input. And 82.
  • the console 30 includes a CPU 84 for controlling the operation of the entire apparatus, a ROM 86 in which various programs including control programs are stored in advance, a RAM 87 for temporarily storing various data, and various data.
  • An HDD (hard disk drive) 88 that stores and holds, a display driver 92 that controls the display of various information on the display 80, and an operation input detection unit 90 that detects an operation state of the operation panel 82. .
  • the console 30 transmits and receives various information such as irradiation conditions to be described later to and from the image processing device 23 and the radiation generation device 24 by wireless communication, and various types of image data and the like to and from the electronic cassette 20.
  • An I / F (for example, a wireless communication unit) 96 and an I / O 94 that transmit and receive information are provided.
  • the CPU 84, the ROM 86, the RAM 87, the HDD 88, the display driver 92, the operation input detection unit 90, the I / O 94, and the wireless communication unit 96 are mutually connected via a bus 98 such as a system bus or control bus. Therefore, the CPU 84 can access the ROM 86, the RAM 87, and the HDD 88, controls the display of various information on the display 80 via the display driver 92, and the radiation generator 24 and the electronics via the wireless communication unit 96. Control of transmission and reception of various information with the cassette 20 can be performed respectively. In addition, the CPU 84 can grasp the operation state of the user on the operation panel 82 through the operation input detection unit 90.
  • the image processing device 23 transmits and receives various information such as irradiation conditions to and from the console 30 (for example, a wireless communication unit) 100, and the electronic cassette 20 and the radiation generator 24 based on the irradiation conditions. And an image processing control unit 102 for controlling.
  • the radiation generator 24 also includes a radiation irradiation control unit 22 that controls the radiation irradiation from the radiation irradiation source 22A.
  • the image processing control unit 102 includes a system control unit 104, a panel control unit 106, and an image processing control unit 108, and exchanges information with each other via a bus 110.
  • the panel control unit 106 receives information from the electronic cassette 20 wirelessly or by wire, and the image processing control unit 108 performs image processing.
  • the system control unit 104 receives information such as tube voltage and tube current under the irradiation conditions from the console 30, and causes the radiation X to be irradiated from the radiation irradiation source 22A of the radiation irradiation control unit 22 based on the received irradiation conditions. Take control.
  • an area to be noted may be limited with respect to the entire imaging area.
  • an almost stationary organ or skeleton is an image of interest.
  • a heart beating organ or a catheter tube guided and moved in a blood vessel is often an image of interest.
  • the imaging system 16 has a function of automatically setting the region of interest based on the operation state of the captured image, and when there is an instruction to perform imaging, after radiation image imaging preparation control Control for setting a region of interest (hereinafter sometimes referred to as “ROI”) is performed.
  • the ROI may be manually set by designating the displayed image.
  • the radiation dose of the radiation to the subject is feedback-corrected by ABC “Auto Brightness Control” control to obtain appropriate image information.
  • ABC “Auto Brightness Control” control to obtain appropriate image information.
  • the non-interest region is extracted, and the degree of change of the gradation signal (hereinafter sometimes referred to as QL value) in the non-interest region To make it smaller.
  • QL value is a value corresponding to the film density of a radiation image obtained by irradiating radiation, and may be a gray scale signal itself, or a predetermined process was performed on the gray scale signal. It may be a signal.
  • FIG. 5 is a functional block diagram specialized in a control system for radiation image capturing (including ROI setting) in the imaging system 16 (mainly, the electronic cassette 20, the console 30, the image processing device 23, the radiation generating device 24). It is. Note that this block diagram is a classification of radiation imaging control by function, and does not limit the hardware configuration.
  • the imaging system 16 includes a radiation dose irradiation control unit 22, a radiation dose adjustment unit 120, a TFT substrate 74, a gradation signal acquisition unit 122, a gradation signal adjustment unit 124, and a region of interest (ROI) setting unit 138, region of interest extraction unit 140, non-interest region extraction unit 126, still image generation unit 128, moving image editing unit 130, display driver 92, display 80, average QL value calculation unit 132, ABC control unit 134, and reference QL value memory It has 136 functions.
  • ROI region of interest
  • the radiation irradiation control unit 22 irradiates radiation from the radiation irradiation source 22A based on the radiation dose adjusted by the radiation dose adjusting unit 120.
  • the radiation emitted from the radiation control unit 22 to the subject passes through the subject and reaches the radiation detector 26 (see FIG. 3) of the electronic cassette 20.
  • the radiation detector 26 the phosphor film 56 (see FIG. 3) emits light with a light amount corresponding to the radiation amount, and is photoelectrically converted by the TFT substrate 74 to generate a gradation signal.
  • the gradation signal acquisition unit 122 acquires the gradation signal generated by the TFT substrate 74 and sends the gradation signal to the gradation signal adjustment unit 124.
  • the photoelectric conversion signal may be an analog signal or may be a signal after being converted into a digital signal by the control unit in the electronic cassette 20.
  • the change degree of the gradation signal (QL value) due to ABC control is lower than the change degree of the gradation signal of the region of interest set by the region of interest (ROI) setting unit 138.
  • the gradation signal is adjusted so that the degree of change is smaller.
  • the degree of change of the non-interest region is reduced by fixing the lower bits of the gradation signal of the non-interest region to a predetermined value (for example, “0” or “1”).
  • the still image generation unit 128 sequentially generates still images based on the gradation signal of one frame.
  • the photoelectric conversion signal itself sent from the electronic cassette 20 differs between moving image shooting and still image shooting, and for example, in the case of moving image shooting as in the present embodiment, the transfer speed is set. A binning process is performed to give priority.
  • image data based on the maximum number of pixels in the TFT substrate 74 is generated in order to give priority to the image quality.
  • the moving image editing unit 130 performs moving image editing by combining the image data of each frame generated by the still image generating unit 128.
  • the edited moving image is displayed on the display 80 via the display driver 92.
  • the still image generated by the still image generation unit 128 is displayed on the display 80 via the display driver 92.
  • a region of interest (ROI) setting unit 138 sets a region of interest by performing pattern matching, detecting a region having a large amount of movement, and the like.
  • the region of interest may be set by the user's operation.
  • the non-interest region extraction unit 126 extracts a portion of the non-interest region based on the region of interest set by the region of interest (ROI) setting unit 138, and the region of interest extraction unit 140 sets the region of interest (ROI) setting unit 138. Extract the part of the region of interest set by.
  • the average QL calculation unit 132 calculates the average value of the QL values of the region of interest in each frame (or one frame appropriately extracted) of the moving image.
  • the calculation result of the average value QL value calculation unit 132 is sent to the ABC control unit 134.
  • the ABC control unit 134 compares the QL average value calculated by the average QL value calculation unit 132 with the reference QL value stored in the reference QL value memory 136 to converge the QL average value to the reference QL value.
  • Correction information .DELTA.X is generated.
  • the correction information ⁇ X is applied as a correction coefficient to increase or decrease the radiation dose (radiation energy) emitted from the radiation irradiation source 22A.
  • the correction information ⁇ X generated by the ABC control unit 134 is sent to the radiation dose adjustment unit 120.
  • the radiation dose adjustment unit 120 increases or decreases the radiation dose XN based on the correction information ⁇ X (XN ⁇ XN ⁇ ⁇ X). That is, at the time when the radiation instruction is issued, the radiation dose adjustment unit 120 starts radiation from a predetermined initial value, and thereafter increases or decreases the radiation dose based on the correction information ⁇ X to become the reference QL value. to correct.
  • the correction information ⁇ X is used as a coefficient for multiplication (division), but may be an addition (subtraction) coefficient (XNXXN + ⁇ XN).
  • the ABC control unit 134 corrects the radiation amount.
  • the radiation dose may be corrected so that the operation value represented by the average value of the gradation signals in a part of the still image information becomes a value in a predetermined range.
  • the ABC control unit 134 sets the occurrence frequency of the gradation signal of one frame to a histogram (for example, a histogram in which the horizontal axis is the gradation signal and the vertical axis is the occurrence frequency), the occurrence frequency is maximum.
  • the radiation dose may be corrected so that the gray level (or the gray level within a predetermined range including the maximum gray level) falls within a predetermined range of values, or in part of still image information of one frame.
  • the radiation dose may be corrected such that another calculated value (addition value of the gradation signal, etc.) other than the average value of the gradation signal becomes a predetermined value (or a value in a predetermined range).
  • addition value of the gradation signal as the operation value, for example, weighting is performed according to the pixel position corresponding to the gradation signal in still image information of one frame, and the value obtained by adding the weighted gradation signal May be used.
  • the weighting may be to increase the weighting factor in the center of the region of interest (ROI) and lower the weighting factor toward the periphery, and setting of the weighting factor is stepwise (for example, in two stages) It may be continuous or it may be defined by a function.
  • ROI region of interest
  • setting of the weighting factor is stepwise (for example, in two stages) It may be continuous or it may be defined by a function.
  • FIG. 6 is a functional block diagram showing the detailed function of the gradation signal adjustment unit 124. As shown in FIG. 6
  • the gradation signal adjustment unit 124 includes the gradation signal reception unit 150, the adjustment gradation signal frame memory 152, the coordinates (x, y) pixel extraction unit 154, and the non-interest region image gradation signal memory.
  • a function of the coordinate (x, y) extraction unit 158, the collation unit 160, the lower bit adjustment processing unit 162, the lower bit data memory 164, the adjusted gradation signal frame memory 166, and the gradation signal transmission unit 168 is provided.
  • the gradation signal reception unit 150 receives the gradation signal acquired by the gradation signal acquisition unit 122 and stores the gradation signal in the pre-adjustment gradation signal frame memory 152.
  • the coordinate (x, y) extraction unit 154 sequentially extracts the gradation signal stored in the pre-adjustment gradation signal frame memory 152 for each coordinate, and sends it to the collation unit 160.
  • the grayscale signal of the non-interest region extracted by the non-interest region extraction unit 126 is temporarily stored in the non-interest region image grayscale signal memory 156.
  • the coordinate (x, y) extraction unit 158 sequentially extracts the non-interest region images stored in the non-interest region image tone signal memory 156 for each coordinate and sends the non-interest region images to the collation unit 160.
  • the collation unit 160 determines whether or not it is a pixel of the non-interest region image, sends the gradation signal of the non-interest region image to the lower bit adjustment processing unit 162, and adjustment of the image gradation signal of the interest region is unnecessary.
  • the adjusted gray scale signal frame memory 166 is stored as it is as a pixel gray scale signal.
  • the lower bit adjustment processing unit 162 reads out a value (for example, “0” or “1”) stored in advance in the lower bit data memory 164, and lower bits (for example, 16 bits) of the grayscale signal of the non-interest area image.
  • the read out value is assigned to the lower 8 bits in the middle, etc., and the adjusted value is stored in the adjusted gradation signal frame memory 166 as an adjusted pixel gradation signal.
  • a predetermined value (“00010001”) is set to lower 8 bits in 16 bits.
  • “10001000” may be assigned.
  • the lower bits to be adjusted are not limited to the lower 8 bits of the 16 bits.
  • the adjusted gradation signal frame memory 166 transmits the gradation signal to the still image generation unit 128 via the gradation signal transmission unit 168 when the gradation signal for one frame is stored.
  • the change degree of the QL value becomes smaller than that of the interest region, and the flicker of the non-interest region is reduced when displaying the moving image.
  • FIG. 7 is a flowchart showing a radiation image capturing preparation control routine.
  • step 200 it is determined whether or not a photographing instruction has been issued. If the determination is negative, the routine ends. If the determination is positive, the process proceeds to step 202.
  • step 202 an initial information input screen is displayed on the display 80, and the process moves to step 204. That is, the display driver 92 is controlled to cause the display 80 to display a predetermined initial information input screen.
  • step 204 it is determined whether or not predetermined information is input, and the process waits until the determination is affirmed, and then proceeds to step 206.
  • the initial information input screen for example, the name of the subject who is about to take a radiation image, the region to be taken, the posture at the time of shooting, and the irradiation condition of the radiation X at the time of shooting (in the present embodiment, radiation X is irradiated And a message prompting the user to input a tube voltage and a tube current), and an input region of such information.
  • the photographer can set the name of the subject to be imaged, the region to be imaged, the posture at the time of imaging, and the irradiation condition to the corresponding input area. Enter through.
  • the photographer enters the radiation imaging room 32 with the subject and, for example, in the case of a recumbent position, the electronic cassette 20 is held by the holding portion 44 of the corresponding support table 36, and the radiation irradiation source 22A is supported.
  • the subject After positioning at the position, the subject is positioned at a predetermined imaging position (positioning).
  • a radiographic image is taken in a state in which the holding portion does not hold the electronic cassette 20 such as an arm portion or a leg portion, the subject and the electronic cassette 20 are set in a state where the imaging target portion can be photographed.
  • the radiation source 22A is positioned.
  • step 204 is affirmed and the process moves to step 206.
  • step 204 is an infinite loop, but forced termination may be performed by the operation of a cancel button provided on the operation panel 82.
  • step 206 the information (hereinafter referred to as "initial information") input on the initial information input screen is transmitted to the electronic cassette 20 via the wireless communication unit 96, and then the process proceeds to the next step 208,
  • the irradiation condition is set by transmitting the irradiation condition included in the initial information to the radiation generation apparatus 24 via the wireless communication unit 96.
  • the image processing control unit 102 of the radiation generation apparatus 24 prepares for irradiation under the received irradiation conditions.
  • step 210 the start of ABC control is instructed, and then, the process proceeds to step 212, and instruction information for instructing the start of radiation irradiation is transmitted to the radiation generation apparatus 24 via the wireless communication unit 96, and this routine Ends.
  • FIG. 8 is a flowchart showing a radiation irradiation control routine.
  • step 300 it is determined whether or not an irradiation start instruction has been issued. If a negative determination is made, this routine ends, and if a positive determination is made, the process proceeds to step 302.
  • step 302 the steady state radiation dose (initial value) XN is read, and the process proceeds to step 304.
  • step 304 irradiation is started with the read out steady-state radiation dose, and the process proceeds to step 306. That is, by applying the tube voltage and the tube current according to the irradiation upper limit received from the console 30 to the radiation generator 24, the irradiation from the radiation irradiation source 22A is started.
  • the radiation X emitted from the radiation source 22A reaches the electronic cassette 20 after being transmitted through the subject.
  • step 306 the radiation dose correction information currently stored is read out, and the process proceeds to step 306.
  • the radiation dose correction information is generated by ABC control, and is stored as a correction coefficient ⁇ X.
  • step 308 correction processing based on ABC control is performed, and the process proceeds to step 310. That is, the average value of the QL values of the region of interest image is calculated based on the gradation signal (QL value) obtained from the electronic cassette 20, and the average value of the QL values is compared with a predetermined threshold value, It is feedback controlled to the radiation dose so as to converge to the threshold value.
  • QL value the gradation signal
  • step 310 it is determined whether or not there is an instruction to end imaging, and if the determination is affirmed, the process proceeds to step 312, and if denied, the process returns to step 306 and the above-described process is repeated.
  • step 312 the irradiation is ended, and the radiation irradiation control is ended.
  • FIG. 9 is a flowchart showing an image processing control routine.
  • step 400 gradation information for one frame is sequentially fetched, and the process proceeds to step 402. That is, the gradation signal generated by the TFT substrate 74 of the electronic cassette 20 is sequentially taken into the gradation signal acquisition unit 122.
  • step 402 a still image is generated, and the process proceeds to step 404. That is, when the gradation signal of one frame is taken in, the still image generation unit 128 generates a still image. In addition, at the time of generation of a still image, a still image on which a result adjusted by gradation adjustment control described later is reflected is generated.
  • step 404 a moving image editing process is performed, and the process moves to step 406.
  • moving image editing is performed by the moving image editing unit 130 by combining the still images of each frame generated by the still image generating unit 128.
  • step 406 image display processing is performed, and the process moves to step 408.
  • display on the display 80 is performed by the display driver 92 by transmitting a moving image generated by the moving image editing process to the display driver 92.
  • a region of interest setting is performed, and the process moves to step 410.
  • the setting of the region of interest is performed by, for example, pattern matching, detection of a region having a large amount of movement, or the like to set the region of interest, but the setting of the region of interest may be performed by the user's operation.
  • step 410 the tone signal of the set region of interest is extracted by the region of interest extraction unit 140, and the process proceeds to step 412.
  • step 412 the average QL value of the grayscale signal of the region of interest is calculated by the average QL value calculator 132, and the process proceeds to step 414 where the reference QL value stored in the reference QL value memory 136 is read. Proceed to step 416.
  • step 416 the calculated average QL value and the read reference QL value are compared by the ABC control unit 134 to determine whether or not correction is possible, and the process proceeds to step 418.
  • the determination as to whether the correction is possible may be a so-called on / off determination that a predetermined amount of correction is performed if the difference is greater than or equal to a predetermined result in the comparison result, and no correction is performed if the difference is less than the predetermined
  • it may be a solution calculated by a predetermined arithmetic expression (for example, an arithmetic expression based on PID control or the like) based on the difference.
  • step 418 the correction information ⁇ X of the radiation amount is generated by the ABC control unit 134 based on the comparison / correction determination result in step 416, and the process proceeds to step 420.
  • step 420 the generated correction information ⁇ X is stored by being sent to the radiation dose adjustment unit 120, and the image processing control is ended.
  • FIG. 10 is a flowchart showing a tone adjustment control routine of the tone adjustment unit.
  • step 500 the gradation signal reception unit 150 receives the gradation signal before adjustment acquired by the gradation signal acquisition unit 122, and the process proceeds to step 502.
  • step 502 the gradation signal before adjustment is temporarily stored in the pre-adjustment gradation signal frame memory 152 in units of one frame, and the process proceeds to step 504.
  • step 504 the tone signal of the non-interest region image extracted by the non-interest region extraction unit 126 is temporarily stored in the non-interest region image tone signal memory 156, and the process proceeds to step 506.
  • step 506 the coordinate (x, y) extraction unit 154 extracts pixels of the coordinate (x, y) in order of a predetermined scanning direction from the gradation signal before adjustment, and the process proceeds to step 508.
  • step S ⁇ b> 508 the matching unit 160 determines whether the extracted pixel is a pixel to be adjusted. This determination determines whether or not the pixel of the non-interest region extracted by the non-interest region extraction unit 126 (the pixel extracted by the coordinate (x, y) extraction unit 158), and the determination is affirmed In the case, the process proceeds to step 510, and if not, the process proceeds to step 514.
  • step 510 the lower bit data of the non-interest region is read by the lower bit adjustment processing unit 162, and the process proceeds to step 512.
  • the lower bit adjustment processing unit 162 adjusts the lower bits of the gradation signal, and the process proceeds to step 514.
  • adjustment is made to a predetermined value stored in the lower bit data memory 164. For example, the lower 8 bits in 16 bits are adjusted to "00000000" or "11111111".
  • the adjusted gradation signal is temporarily stored in the adjusted gradation signal frame memory 166 in units of one frame, and the process proceeds to step 516.
  • step 516 it is judged whether or not the gradation signal for one frame is stored in the adjusted gradation signal frame memory 166, and if the judgment is negative, the process returns to step 506 and the gradation signal for one frame Is stored, and the above process is repeated until the determination is affirmed, and when the determination is affirmed, the process proceeds to step 518.
  • step 518 the adjusted gradation signal is sent to the still image generation unit 128, and the gradation adjustment control is ended.
  • the change degree of the gradation of the non-interest region is higher than the gradation signal of the interest region. It can be made smaller.
  • the gradation change of the non-interest region is smaller than that of the region of interest, so it is possible to suppress flicker due to ABC control when shooting a moving image and reduce eye fatigue.
  • the lower bits of the non-interest region are read in step 510, and the lower bits of the non-interest region are adjusted to a predetermined value in step 512, whereby the QL value of the non-interest region is Adjustment was made to reduce the degree of change.
  • the modified example an example will be described in which another method of making the degree of change of the QL value of the non-interest region smaller than the interest region is applied.
  • the variation value of the QL value of the (N-1) frame is applied to the non-interest region of the N frame, and the variation of the QL value is delayed for the region other than the region of interest.
  • the previous tone memory of one frame is provided instead of the lower bit data memory 164, and the previous tone signal replacement process of one frame is provided instead of the lower bit adjustment processing unit 162.
  • the gradation signal of one frame before is stored, and the pixels of the non-interest region are replaced with the gradation signal of one frame before.
  • FIG. 11 is a flowchart showing the tone adjustment control routine of the tone adjustment unit of the modification. The same processes as those in the above embodiment will be described with the same reference numerals.
  • step 500 the gradation signal reception unit 150 receives the gradation signal before adjustment acquired by the gradation signal acquisition unit 122, and the process proceeds to step 502.
  • step 502 the gradation signal before adjustment is temporarily stored in the pre-adjustment gradation signal frame memory 152 in units of one frame, and the process proceeds to step 504.
  • step 504 the tone signal of the non-interest region image extracted by the non-interest region extraction unit 126 is temporarily stored in the non-interest region image tone signal memory 156, and the process proceeds to step 506.
  • step 506 the coordinate (x, y) extraction unit 154 extracts pixels of the coordinate (x, y) in order of a predetermined scanning direction from the gradation signal before adjustment, and the process proceeds to step 508.
  • step S ⁇ b> 508 the matching unit 160 determines whether the extracted pixel is a pixel to be adjusted. This determination determines whether or not the pixel of the non-interest region extracted by the non-interest region extraction unit 126 (the pixel extracted by the coordinate (x, y) extraction unit 158), and the determination is affirmed In the case, the process proceeds to step 511, and in the case of being denied, the process proceeds to step 514.
  • step 511 the gradation signal of one frame before is read, and the process proceeds to step 513.
  • step 513 adjustment is performed to replace the tone signal with the tone signal one frame before, and the process moves to step 514.
  • the adjusted gradation signal is temporarily stored in the adjusted gradation signal frame memory 166 in units of one frame, and the process proceeds to step 516.
  • step 516 it is judged whether or not the gradation signal for one frame is stored in the adjusted gradation signal frame memory 166, and if the judgment is negative, the process returns to step 506 and the gradation signal for one frame Is stored, and the above process is repeated until the determination is affirmed, and when the determination is affirmed, the process proceeds to step 518.
  • step 518 the adjusted gradation signal is sent to the still image generation unit 128, and the gradation adjustment control is ended.
  • the gradation signal adjustment unit 124 applies the variation value of the QL value of the (N-1) frame to the non-interest region of the N frame to change the QL value for the region other than the region of interest.
  • the tone signal is adjusted so as to delay.
  • the fluctuation time constant of the QL value of the non-interest region can be made slower and more gently than the region of interest, so that flickering of the image can be suppressed.
  • the gradation signal adjustment unit 124 adjusts the gradation signal of the non-interest region so as to delay the fluctuation time constant by applying the gradation signal of the previous frame to the non-interest region
  • the gradation signal adjustment unit 124 may adjust the gradation signal of the non-interest region so as to further delay the fluctuation time constant by applying (N ⁇ 1) frames for several consecutive frames.
  • the gradation signal adjustment unit 124 may adjust the lower bits of the non-interest region to fluctuate at a cycle lower than the control period of the interest region. For example, the frame rate of the non-interest region may be lowered relative to the frame rate of the region of interest.
  • the gradation signal adjustment unit 124 changes the QL value of the (N-1) frame until the ABC control ends.
  • a value may be applied to keep the QL value of the non-interest region constant.
  • the X-ray is applied as the radiation of the present invention, but the present invention is not limited to this, and other radiation such as ⁇ -ray and ⁇ -ray may be used. included.

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Medical Informatics (AREA)
  • Physics & Mathematics (AREA)
  • Pathology (AREA)
  • Public Health (AREA)
  • Biophysics (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Optics & Photonics (AREA)
  • Veterinary Medicine (AREA)
  • Radiology & Medical Imaging (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Molecular Biology (AREA)
  • Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Mathematical Physics (AREA)
  • Human Computer Interaction (AREA)
  • Apparatus For Radiation Diagnosis (AREA)

Abstract

This fluoroscopic processing device is provided with: an image information generation unit that generates one frame of still image information on the basis of a digital gradient signal that is in accordance with the amount of radiation received at each pixel, and continuously combines the still image information of a plurality of frames to generate moving picture information; a region-of-interest setting unit that sets a portion of an image indicated by the moving picture information as a region of interest; a control unit that performs feedback control of the set value of radiation energy at a predetermined control cycle in a manner so that the computed value of the gradient signal that is a portion of the still image information of at least one frame becomes a value in a predetermined range; and an adjustment unit that adjusts the gradient signal corresponding to a region of non-interest in a manner so that the degree of change of the gradient signal resulting from the feedback control is less in the region of non-interest than the region of interest.

Description

放射線動画処理装置、放射線動画撮影装置、放射線動画撮影システム、放射線動画撮影方法、及び放射線動画撮影プログラムRadiation movie processing apparatus, radiation movie shooting apparatus, radiation movie shooting system, radiation movie shooting method, and radiation movie shooting program
　本発明は、放射線動画撮影処理装置、放射線動画撮影装置、放射線動画撮影システム、放射線動画撮影方法、及び放射線動画撮影プログラムに関する。 The present invention relates to a radiation moving image photographing processing apparatus, a radiation moving image photographing apparatus, a radiation moving image photographing system, a radiation moving image photographing method, and a radiation moving image photographing program.
　近年、ＴＦＴ（Thin Film Transistor）アクティブマトリクス基板上に放射線感応層を配置し、放射線量をデジタルデータ（電気信号）に変換できるＦＰＤ（Flat Panel Detector）等の放射線検出器（「電子カセッテ」等という場合がある）が実用化されており、この放射線検出器を用いて、照射された放射線量により表わされる放射線画像を撮影する放射線画像撮影装置が実用化されている。 In recent years, a radiation sensitive layer is disposed on a TFT (Thin Film Transistor) active matrix substrate, and a radiation detector ("Electronic cassette" or the like) such as FPD (Flat Panel Detector) capable of converting a radiation dose into digital data (electric signal) In some cases, a radiation image capturing apparatus for capturing a radiation image represented by an irradiated radiation dose using this radiation detector has been put to practical use.
　なお、放射線量は、例えば、互換をもって発光量に変換され、その後、電気信号に変換される間接変換方式と、放射線量から直接電気信号に変換される直接変換方式とがあり、適宜選択して採用される。 Note that the radiation dose is, for example, compatiblely converted to the light emission amount, and then there is an indirect conversion method in which it is converted into an electrical signal, and a direct conversion method in which a radiation dose is directly converted into an electrical signal. Will be adopted.
　このような放射線画像撮影装置の一例としては、例えば、特開２００７-９７９７７号公報に記載の技術などが提案されている。 As an example of such a radiation imaging apparatus, for example, the technology described in JP-A-2007-97977 has been proposed.
　特開２００７-９７９７７号公報に記載の技術では、撮影された放射線画像を関心領域（ＲＯＩ:Region Of Interest）と非関心領域とに分けて、非関心領域の放射線画像をデータ圧縮することによりデータの大きさを小さくして、データ転送時間を短くすることが提案されている。 In the technology described in Japanese Patent Application Laid-Open No. 2007-97977, data is obtained by dividing a captured radiation image into a region of interest (ROI) and a non-interest region, and compressing the radiation image of the non-interest region. It has been proposed to reduce the data transfer time by reducing the size of.
　また、上記のような放射線画像撮影装置では、一定時間毎に放射線検出器で検出した画像情報を連続して再生することで、所謂動画像を表示する。動画では、静止画に比べてデータ量が増加するため、特開２００７-９７９７７号公報の技術を用いることによってデータ転送時間を短くする技術は有効な技術である。 In addition, in the radiation image capturing apparatus as described above, a so-called moving image is displayed by continuously reproducing the image information detected by the radiation detector at predetermined time intervals. In moving pictures, the amount of data increases as compared to still pictures. Therefore, the technique of shortening the data transfer time by using the technique of JP-A-2007-97977 is an effective technique.
特開２００７-９７９７７号公報Japanese Patent Application Publication No. 2007-97977
　ところで、放射線画像撮影装置では、撮影した画像情報に基づき、放射線量を制御して、放射線検出器による検出状態を最適に維持するフィードバック制御（ＡＢＣ「Auto Brightness Control」制御）が行われるが、動画撮影においても必須とされる。 By the way, in the radiation image capturing apparatus, feedback control (ABC “Auto Brightness Control” control) is performed to control the radiation dose based on the captured image information to optimally maintain the detection state by the radiation detector. It is also essential for shooting.
　動画撮影では、一般的に、静止画よりもＲＯＩが狭く、ユーザが注視している領域も狭いため、ＡＢＣ制御によって画像全体の輝度が大きく上下するように変動すると、表示された画像のちらつきによってユーザの目の疲れを引き起こす恐れがある。しかし、特開２００７-９７９７７号公報に記載の技術では、動画撮影やＡＢＣ制御時の画像のちらつきについては考慮していない。 Generally, in moving image shooting, the ROI is narrower than that of a still image and the area at which the user is gazing is also narrow. Therefore, if the brightness of the entire image fluctuates to a large or small part by ABC control, the flicker of the displayed image It may cause tiredness of the user's eyes. However, in the technique described in Japanese Patent Application Laid-Open No. 2007-97977, the flickering of images at the time of moving image shooting and ABC control is not taken into consideration.
　本発明は、上記事実を考慮して成されたもので、動画のＡＢＣ制御による画像のちらつきを抑制して目の疲れを軽減することができる放射線動画撮影処理装置、放射線動画撮影装置、放射線動画撮影システム、放射線動画撮影方法、及び放射線動画撮影プログラムを提供する。 The present invention has been made in consideration of the above facts, and is capable of suppressing flickering of an image by ABC control of a moving image and reducing eye fatigue, a radiation moving image capturing apparatus, a radiation moving image, Provided are an imaging system, a radiation moving image capturing method, and a radiation moving image capturing program.
　本発明の第１の態様によれば、放射線動画処理装置は、設定された設定値に応じた放射線照射エネルギーで放射線を照射する放射線照射部から照射されて被検体を通過した放射線量を、複数の画素を備えた放射線検出器で受け、当該画素毎に受ける放射線量に応じたデジタルの階調信号を出力する放射線画像撮影部から出力される前記階調信号に基づいて、１フレームの静止画像情報を生成し、且つ、前記静止画像情報を連続的に複数フレーム組み合わせて動画像情報を生成する画像情報生成部と、前記画像情報生成部で生成された前記動画像情報が示す画像の一部を関心領域として設定する関心領域設定部と、前記階調信号に基づいて、少なくとも１フレームの前記静止画像情報の一部における前記階調信号の演算値が予め定めた範囲の値になるように、前記放射線照射部から照射される前記放射線エネルギーの設定値を所定の制御周期でフィードバック制御する制御部と、前記制御部の前記フィードバック制御による前記階調信号の変化度合が、前記関心領域設定部によって設定された前記関心領域よりも前記関心領域以外の非関心領域の方が小さくなるように、前記非関心領域に対応する前記階調信号を調整する調整部と、を備える。 According to the first aspect of the present invention, the radiation moving image processing apparatus is configured to transmit a plurality of radiation doses that have been emitted from the radiation irradiating unit that irradiates radiation with radiation irradiation energy according to the set value that has been set. And a still image of one frame based on the gradation signal output from the radiation image capturing unit that outputs a digital gradation signal according to the radiation amount received for each of the pixels. An image information generation unit that generates information and generates moving image information by combining a plurality of frames of the still image information continuously, and a part of the image indicated by the moving image information generated by the image information generation unit The region of interest setting unit sets the region of interest as the region of interest, and the operation value of the gradation signal in a part of the still image information of at least one frame is determined in advance based on the The control unit performs feedback control of the setting value of the radiation energy irradiated from the radiation irradiating unit at a predetermined control cycle, and the change degree of the gradation signal by the feedback control of the control unit is An adjusting unit configured to adjust the gray scale signal corresponding to the non-interest region such that the non-interest region other than the interest region is smaller than the region of interest set by the region-of-interest setting unit.
　本発明の第１の態様による放射線動画処理装置によれば、放射線照射部では、設定された設定値に応じた放射線照射エネルギーで放射線が照射され、放射線画像撮影部では、放射線照射部から照射されて被検体を通過した放射線量が放射線検出器に照射される。また、放射線検出器では、放射線が照射されると画素毎に受ける放射線量に応じたデジタルの階調信号が出力される。 According to the radiation moving image processing apparatus of the first aspect of the present invention, the radiation irradiation unit irradiates radiation with radiation irradiation energy according to the set value set, and the radiation image capturing unit irradiates radiation from the radiation irradiation unit The radiation amount which has passed through the subject is then irradiated to the radiation detector. Further, in the radiation detector, when the radiation is irradiated, a digital gradation signal according to the radiation amount received for each pixel is output.
　また、画像情報生成部では、放射線画像撮影部から出力される階調信号に基づいて１フレームの静止画像情報が生成され、且つ、静止画像情報を連続的に複数フレーム組み合わせて動画像情報が生成され、関心領域設定部では、画像情報生成部で生成された動画像情報が示す画像の一部が関心領域として設定される。 Further, in the image information generation unit, still image information of one frame is generated based on the gradation signal output from the radiation image capturing unit, and moving image information is generated by continuously combining a plurality of still image information. In the region-of-interest setting unit, a part of the image indicated by the moving image information generated by the image information generation unit is set as the region of interest.
　そして、制御部では、階調信号に基づいて、少なくとも１フレームの静止画像情報の一部における階調信号の演算値が予め定めた範囲の値になるように、放射線照射部から照射される放射線エネルギーの設定値が所定の制御周期でフィードバック制御される（ＡＢＣ制御）。なお、階調信号の演算値は、本発明の第２の態様によれば、本発明の第１の態様において、前記関心領域の階調信号の平均値としてもよいし、重み付けを含む加算に基づく値であってもよいし、または他の演算値を適用するようにしてもよい。 Then, in the control unit, the radiation irradiated from the radiation irradiating unit such that the operation value of the gradation signal in a part of at least one frame of the still image information becomes a value in a predetermined range based on the gradation signal. The set value of energy is feedback controlled in a predetermined control cycle (ABC control). According to the second aspect of the present invention, in the first aspect of the present invention, the operation value of the gray level signal may be an average value of the gray level signals of the region of interest. It may be a value based on it, or another calculated value may be applied.
　ところで、制御部によってフィードバック制御されることにより、画像のちらつきを生じる。フィードバック制御量が大きくなると画像のちらつきも大きくなるため目の疲れにつながる。 By the way, the image is flickered by feedback control by the control unit. As the amount of feedback control increases, the flicker of the image also increases, leading to eye fatigue.
　そこで、調整部では、制御部のフィードバック制御による階調信号の変化度合が、関心領域設定部によって設定された関心領域よりも非関心領域の方が小さくなるように、非関心領域の画素として取得する階調信号が調整される。すなわち、非関心領域については、関心領域よりも階調信号の変化度合が小さくなるので、画像のちらつきも小さくなる。従って、動画の場合のＡＢＣ制御による画像のちらつきを抑制して、ユーザの目の疲れを軽減することができる。 Therefore, the adjustment unit acquires pixels of the non-interest region so that the change degree of the gradation signal by feedback control of the control unit is smaller in the non-interest region than in the interest region set by the region-of-interest setting unit. Tone signal is adjusted. That is, in the non-interest region, since the degree of change of the gradation signal is smaller than that in the region of interest, the flickering of the image is also reduced. Therefore, it is possible to suppress the flicker of the image by the ABC control in the case of the moving image, and to alleviate the tiredness of the user's eyes.
　なお、本発明の第３の態様によれば、本発明の第１又は２の態様において、前記階調信号が、Ｎ（Ｎは２以上の自然数）ビットのデジタル信号であり、前記調整部が、前記Ｎビットの下位のｎ（ｎ＜Ｎの自然数）ビットの信号を予め定めた値に調整するようにしてもよい。例えば、本発明の第４の態様によれば、本発明の第３の態様において、前記調整部は、前記予め定めた値として、「０」または「１」に調整するようにしてもよい。これによって関心領域よりも非関心領域の階調信号の変化度合を小さくすることが可能となる。 According to a third aspect of the present invention, in the first or second aspect of the present invention, the gradation signal is a digital signal of N (N is a natural number of 2 or more) bits, and the adjustment unit is The low-order n (n <N natural number) bit signal of the N bits may be adjusted to a predetermined value. For example, according to the fourth aspect of the present invention, in the third aspect of the present invention, the adjustment unit may adjust the value to “0” or “1” as the predetermined value. This makes it possible to make the degree of change of the gradation signal in the non-interest region smaller than the interest region.
　また、本発明の第５の態様によれば、本発明の第１又は２の態様において、前記調整部は、前記非関心画像の画素として取得する前記階調信号として（Ｎ－１）フレームの階調信号を適用して、前記関心領域よりも非関心領域の時定数が遅くなるように調整するようにしてもよい。このように階調信号調整しても関心領域よりも非関心領域の階調信号の変化度合を小さくすることが可能となる。 Further, according to a fifth aspect of the present invention, in the first or second aspect of the present invention, the adjustment unit is configured to acquire the gradation signal as the pixel of the non-interest image in the (N-1) frame. A gradation signal may be applied to adjust the time constant of the non-interest region to be later than the interest region. As described above, even if the gradation signal adjustment is performed, it is possible to make the degree of change of the gradation signal in the non-interest region smaller than the region of interest.
　また、本発明の第６の態様によれば、本発明の第１又は２の態様において、前記調整部は、前記非関心領域の画素として取得する前記階調信号を、前記制御部による制御が終了するまで一定に保持するように調整するようにしてもよい。このように階調信号を調整しても関心領域よりも非関心領域の階調信号の変化度合を小さくすることが可能となる。 Further, according to a sixth aspect of the present invention, in the first or second aspect of the present invention, the adjustment unit controls the gradation signal acquired as a pixel of the non-interest region by the control unit. It may be adjusted to be held constant until the end. As described above, even if the gradation signal is adjusted, it is possible to make the degree of change of the gradation signal in the non-interest region smaller than that in the region of interest.
　さらに、本発明の第７の態様によれば、本発明の第１又は２の態様において、前記調整部は、前記関心領域の階調信号の変化周期よりも前記非関心領域の階調信号の変化周期が遅くなるように前記階調信号を調整するようにしてもよい。このように階調信号を調整しても関心領域よりも非関心領域の階調信号の変化度合を小さくすることが可能となる。 Furthermore, according to the seventh aspect of the present invention, in the first or second aspect of the present invention, the adjustment unit is configured to adjust the gray level signal of the non-interest region more than the change period of the gray level signal of the region of interest. The gradation signal may be adjusted so that the change period is delayed. As described above, even if the gradation signal is adjusted, it is possible to make the degree of change of the gradation signal in the non-interest region smaller than that in the region of interest.
　なお、本発明の第８の態様によれば、設定された設定値に応じた放射線照射エネルギーで放射線を照射する放射線照射部から照射されて被検体を通過した放射線量を、複数の画素を備えた放射線検出器で受け、当該画素毎に受ける放射線量に応じたデジタルの階調信号を出力する放射線画像撮影部と、本発明の第１～７の態様の何れかによる放射線動画処理装置と、を備えた放射線動画撮影装置としてもよい。また、本発明の第９の態様によれば、設定された設定値に応じた放射線照射エネルギーで放射線を照射する放射線照射部と、本発明の第８の態様による放射線動画撮影装置と、を備えた放射線動画撮影システムとしてもよい。 According to the eighth aspect of the present invention, a plurality of pixels are provided with a radiation dose that has been applied from the radiation irradiating unit that irradiates radiation with radiation irradiation energy according to the set value that has been set, and has passed through the subject. A radiation image processing unit which receives a radiation detector and outputs a digital gradation signal according to the radiation amount received for each pixel, and a radiation moving image processing apparatus according to any one of the first to seventh aspects of the present invention; It is good also as a radiographic animation imaging device provided with. Further, according to a ninth aspect of the present invention, there is provided a radiation irradiator for emitting radiation with radiation irradiation energy according to the set value set, and a radiation moving image photographing apparatus according to the eighth aspect of the present invention. It may be a radiation video imaging system.
　一方、本発明の第１０の態様によれば、放射線動画撮影方法は、設定された設定値に応じた放射線エネルギーで被検体に向けて放射線照射部から放射線を照射し、被検体を通過した放射線量を、複数の画素を備えた放射線検出器で受け、当該画素毎に受ける放射線量に応じたデジタルの階調信号に基づいて、１フレームの静止画像情報を生成し、且つ、前記静止画像情報を連続的に複数フレーム組み合わせて動画像情報を生成して、生成した前記動画像情報が示す画像の一部を関心領域として設定し、前記階調信号に基づいて、少なくとも１フレームの前記静止画像情報の一部における前記階調信号の演算値が予め定めた範囲の値になるように、前記放射線エネルギーの設定値を所定の制御周期でフィードバック制御する制御部の前記フィードバック制御による前記階調信号の変化度合が、設定された前記関心領域よりも前記関心領域以外の非関心領域の方が小さくなるように、前記非関心領域に対応する前記階調信号を調整する。 On the other hand, according to the tenth aspect of the present invention, in the radiation moving image photographing method, radiation is irradiated from the radiation irradiating unit toward the subject with radiation energy according to the set value set, and radiation passing through the subject The amount is received by a radiation detector having a plurality of pixels, and one frame of still image information is generated based on a digital gradation signal according to the radiation amount received for each pixel, and the still image information Are sequentially combined to generate moving image information, and a part of the image indicated by the generated moving image information is set as a region of interest, and the still image of at least one frame is set based on the gradation signal. The control unit of the control unit that performs feedback control of the setting value of the radiation energy at a predetermined control cycle such that the operation value of the gradation signal in part of the information becomes a value within a predetermined range. The gradation signal corresponding to the non-interest region is adjusted such that the change degree of the gradation signal due to feedback control is smaller in the non-interest region other than the interest region than the set region of interest .
　本発明の第１０の態様による放射線動画撮影方法によれば、設定された設定値に応じた放射線エネルギーで被検体に向けて放射線を照射し、被検体を通過した放射線量を、複数の画素を備えた放射線検出器で受ける。 According to the radiation moving image radiographing method of the tenth aspect of the present invention, radiation is irradiated toward the subject with radiation energy corresponding to the set value set, and a radiation dose that has passed through the subject is determined by a plurality of pixels. Received by the equipped radiation detector.
　また、放射線検出器の画素毎に受ける放射線量に応じたデジタルの階調信号に基づいて、１フレームの静止画像情報を生成し、且つ、前記静止画像情報を連続的に複数フレーム組み合わせて動画像情報を生成して、生成した動画像情報が示す画像の一部を関心領域として設定する。 In addition, still image information of one frame is generated based on a digital gradation signal according to the radiation amount received for each pixel of the radiation detector, and a plurality of frames of the still image information are continuously combined to form a moving image Information is generated, and a part of the image indicated by the generated moving image information is set as a region of interest.
　ところで、上述のように制御部によってフィードバック制御されることにより、画像のちらつきを生じる。フィードバック制御量が大きくなると画像のちらつきも大きくなるため目の疲れにつながる。 By the way, flickering of an image occurs by being feedback-controlled by the control unit as described above. As the amount of feedback control increases, the flicker of the image also increases, leading to eye fatigue.
　そこで、制御部のフィードバック制御による階調信号の変化度合が、設定された関心領域よりも非関心領域の方が小さくなるように、非関心領域の画素として取得する階調信号を調整する。すなわち、非関心領域については、関心領域よりも階調信号の変化度合が小さくなるので、画像のちらつきも小さくなる。従って、動画の場合のＡＢＣ制御による画像のちらつきを抑制して、ユーザの目の疲れを軽減することができる。なお、階調信号の演算値は、本発明の第１１の態様によれば、本発明の第１０の態様において、前記関心領域の階調信号の平均値としてもよいし、重み付けを含む加算に基づく値であってもよいし、または他の演算値を適用するようにしてもよい。 Therefore, the gradation signal acquired as the pixel of the non-interest region is adjusted so that the change degree of the gradation signal by the feedback control of the control unit becomes smaller in the non-interest region than the set interest region. That is, in the non-interest region, since the degree of change of the gradation signal is smaller than that in the region of interest, the flickering of the image is also reduced. Therefore, it is possible to suppress the flicker of the image by the ABC control in the case of the moving image, and to alleviate the tiredness of the user's eyes. According to the eleventh aspect of the present invention, in the tenth aspect of the present invention, the calculation value of the gradation signal may be an average value of the gradation signal of the region of interest, or an addition including weighting may be performed. It may be a value based on it, or another calculated value may be applied.
　また、本発明の第１２の態様によれば、本発明の第１０又は１１の態様において、前記階調信号が、Ｎ（Ｎは２以上の自然数）ビットのデジタル信号であり、前記非関心領域の画素として取得する前記階調信号の前記Ｎビットの下位のｎ（ｎ＜Ｎの自然数）ビットの信号を予め定めた値に調整するようにしてもよい。例えば、本発明の第１３の態様によれば、本発明の第１２の態様において、前記予め定めた値として、「０」または「１」に調整するようにしてもよい。これによって関心領域よりも非関心領域の階調信号の変化度合を小さくすることが可能となる。 Further, according to a twelfth aspect of the present invention, in the tenth or eleventh aspect of the present invention, the gradation signal is a digital signal of N (N is a natural number of 2 or more) bits, and the non-interest region The signal of the lower n (n <N natural number) bits of the N bits of the gradation signal acquired as the pixel of (1) may be adjusted to a predetermined value. For example, according to a thirteenth aspect of the present invention, in the twelfth aspect of the present invention, the predetermined value may be adjusted to “0” or “1”. This makes it possible to make the degree of change of the gradation signal in the non-interest region smaller than the interest region.
　また、本発明の第１４の態様によれば、本発明の第１０又は１１の態様において、前記非関心画像の画素として取得する前記階調信号として（Ｎ－１）フレームの階調信号を適用して、前記関心領域よりも前記非関心領域の時定数が遅くなるように調整するようにしてもよい。このように階調信号調整しても関心領域よりも非関心領域の階調信号の変化度合を小さくすることが可能となる。 Further, according to a fourteenth aspect of the present invention, in the tenth or eleventh aspect of the present invention, the gradation signal of the (N-1) frame is applied as the gradation signal acquired as a pixel of the non-interest image Then, the time constant of the non-interest region may be adjusted to be later than the interest region. As described above, even if the gradation signal adjustment is performed, it is possible to make the degree of change of the gradation signal in the non-interest region smaller than the region of interest.
　また、本発明の第１５の態様によれば、本発明の第１０又は１１の態様において、前記非関心領域の画素として取得する前記階調信号を、前記フィードバック制御が終了するまで一定に保持するように調整するようにしてもよい。このように階調信号を調整しても関心領域よりも非関心領域の階調信号の変化度合を小さくすることが可能となる。 Further, according to a fifteenth aspect of the present invention, in the tenth or eleventh aspect of the present invention, the gradation signal acquired as a pixel of the non-interest region is held constant until the feedback control is completed. It may be adjusted as follows. As described above, even if the gradation signal is adjusted, it is possible to make the degree of change of the gradation signal in the non-interest region smaller than that in the region of interest.
　さらに、本発明の第１６の態様によれば、本発明の第１０又は１１の態様において、前記関心領域の階調信号の変化周期よりも前記非関心領域の階調信号の変化周期が遅くなるように前記階調信号を調整するようにしてもよい。このように階調信号を調整しても関心領域よりも非関心領域の階調信号の変化度合を小さくすることが可能となる。 Furthermore, according to a sixteenth aspect of the present invention, in the tenth or eleventh aspect of the present invention, the change period of the gradation signal of the non-interest region is later than the change period of the gradation signal of the region of interest. The gradation signal may be adjusted as described above. As described above, even if the gradation signal is adjusted, it is possible to make the degree of change of the gradation signal in the non-interest region smaller than that in the region of interest.
　一方、本発明の第１７の態様によれば、放射線動画撮影プログラムは、コンピュータを本発明の第１～７の態様の何れかによる放射線動画処理装置を構成する各部として機能させるためのものである。 On the other hand, according to a seventeenth aspect of the present invention, a radiation moving image photographing program is for causing a computer to function as each unit constituting a radiation moving image processing apparatus according to any one of the first to seventh aspects of the present invention. .
　従って、本発明によれば、コンピュータを本発明の第１～７の態様の何れかによる放射線動画処理装置を構成する各部として機能させることができるので、本発明の第１の態様による発明と同様に、動画の場合のＡＢＣ制御による画像のちらつきを抑制して、ユーザの目の疲れを軽減することができる。 Therefore, according to the present invention, the computer can be made to function as each unit constituting the radiation moving image processing apparatus according to any one of the first to seventh aspects of the present invention. In addition, it is possible to reduce the tiredness of the user's eyes by suppressing the flicker of the image due to the ABC control in the case of the moving image.
　以上説明した如く本発明では、主として動画撮影する場合に、ＡＢＣ制御による画像のちらつきを抑制して、ユーザの目の疲れを軽減することができる。 As described above, according to the present invention, when shooting moving images mainly, it is possible to suppress the flicker of the image by the ABC control and reduce the tiredness of the user's eyes.
実施の形態に係る放射線情報システムの構成を示すブロック図である。It is a block diagram showing composition of a radiation information system concerning an embodiment. 実施の形態に係る放射線画像撮影システムの放射線撮影室における各装置の配置状態の一例を示す側面図である。It is a side view which shows an example of the arrangement | positioning state of each apparatus in the radiation imaging room of the radiographic imaging system which concerns on embodiment. 実施の形態に係る放射線検出器の３画素部分の概略構成を示す断面模式図である。It is a cross-sectional schematic diagram which shows schematic structure of the 3 pixel part of the radiation detector which concerns on embodiment. 実施の形態に係る撮影システムの制御ブロック図である。It is a control block diagram of an imaging system concerning an embodiment. 実施の形態に係る撮影システムにおける、放射線画像撮影のための制御系に特化した機能ブロック図である。It is a functional block diagram specialized in the control system for radiographic imaging in the imaging system concerning an embodiment. 実施の形態に係る撮影システムにおける階調信号調整部の詳細な機能を示す機能ブロック図である。It is a functional block diagram which shows the detailed function of the gradation signal adjustment part in the imaging | photography system which concerns on embodiment. 実施の形態に係る放射線画像撮影準備制御ルーチンを示すフローチャートである。It is a flowchart which shows the radiographic imaging preparation control routine which concerns on embodiment. 実施の形態に係る放射線照射制御ルーチンを示すフローチャートである。It is a flowchart which shows the radiation irradiation control routine which concerns on embodiment. 実施の形態に係る画像処理制御ルーチンを示すフローチャートである。It is a flowchart which shows the image processing control routine which concerns on embodiment. 実施の形態に係る階調調整部の階調調整制御ルーチンを示すフローチャートである。5 is a flowchart showing a tone adjustment control routine of a tone adjustment unit according to the embodiment. 変形例の階調調整部の階調調整制御ルーチンを示すフローチャートである。It is a flowchart which shows the gradation adjustment control routine of the gradation adjustment part of a modification.
　図１は、本実施の形態に係る放射線情報システム（以下、「ＲＩＳ」（Radiology Information System）という。）１０の概略構成図である。このＲＩＳ１０は、静止画に加え、動画を撮影することが可能である。なお、動画の定義は、静止画を高速に次々と表示して、動画として認知させることを言い、静止画を撮影し、電気信号に変換し、伝送して当該電気信号から静止画を再生する、というプロセスを高速に繰り返すものである。従って、前記「高速」の度合いによって、予め定められた時間内に同一領域（一部又は全部）を複数回撮影し、かつ連続的に再生する、所謂「コマ送り」も動画に包含されるものとする。 FIG. 1 is a schematic configuration diagram of a radiation information system (hereinafter, referred to as “RIS” (Radiology Information System)) 10 according to the present embodiment. This RIS 10 is capable of shooting moving images in addition to still images. In addition, the definition of a moving image means that still images are displayed one after another at high speed and recognized as a moving image, and the still images are photographed, converted into electric signals, and transmitted to reproduce the still images from the electric signals. The process is repeated at high speed. Therefore, depending on the degree of "high speed", so-called "frame feed", in which the same area (part or all) is photographed a plurality of times within a predetermined time and continuously reproduced, is also included in the moving image I assume.
　ＲＩＳ１０は、放射線科部門内における、診療予約、診断記録等の情報管理を行うためのシステムであり、病院情報システム（以下、「ＨＩＳ」（Hospital Information System）という。）の一部を構成する。 The RIS 10 is a system for managing information such as medical treatment reservations and diagnostic records in the radiology department, and constitutes a part of a hospital information system (hereinafter referred to as "HIS" (Hospital Information System)).
　ＲＩＳ１０は、複数台の撮影依頼端末装置（以下、「端末装置」という。）１２、ＲＩＳサーバー１４、および病院内の放射線撮影室（あるいは手術室）の個々に設置された複数の放射線画像撮影システム（以下、「撮影システム」という。）１６を有しており、これらが有線や無線のＬＡＮ（Local Area Network）等から成る病院内ネットワーク１８に各々接続されて構成されている。なお、病院内ネットワーク１８には、ＨＩＳ全体を管理するＨＩＳサーバー（図示省略）が接続されている。また、前記放射線画像撮影システム１６は、単一、或いは３以上の設備であってもよく、図１では、撮影室毎に設置しているが、単一の撮影室に２台以上の放射線画像撮影システム１６を配置してもよい。 The RIS 10 includes a plurality of radiographing systems (hereinafter referred to as "terminals") 12, a RIS server 14, and a plurality of radiographing systems individually installed in radiography rooms (or operating rooms) in a hospital. (Hereafter, it is called "imaging system.") 16, which are respectively connected to an in-hospital network 18 composed of a wired or wireless LAN (Local Area Network) or the like. In addition, the HIS server (illustration omitted) which manages the whole HIS is connected to the network 18 in a hospital. Further, the radiation imaging system 16 may be a single or three or more facilities. In FIG. 1, although it is installed for each imaging room, two or more radiation images are taken in a single imaging room The imaging system 16 may be arranged.
　端末装置１２は、医師や放射線技師が、診断情報や施設予約の入力、閲覧等を行うためのものであり、放射線画像の撮影依頼や撮影予約は、この端末装置１２を介して行われる。各端末装置１２は、表示装置を有するパーソナル・コンピュータを含んで構成され、ＲＩＳサーバー１４と病院内ネットワーク１８を介して相互通信が可能とされている。 The terminal device 12 is used by a doctor or a radiographer to input diagnostic information and facility reservation, to view, and the like. Radiographic image radiographing requests and radiographing reservations are made via the terminal device 12. Each terminal device 12 is configured to include a personal computer having a display device, and can communicate with each other via the RIS server 14 and the hospital network 18.
　一方、ＲＩＳサーバー１４は、各端末装置１２からの撮影依頼を受け付け、撮影システム１６における放射線画像の撮影スケジュールを管理するものであり、データベース１４Ａを含んで構成されている。 On the other hand, the RIS server 14 receives an imaging request from each of the terminal devices 12, manages the imaging schedule of radiation images in the imaging system 16, and includes a database 14A.
　データベース１４Ａは、被検体としての患者（被検者）の属性情報（氏名、性別、生年月日、年齢、血液型、体重、患者ＩＤ（Identification）等）、病歴、受診歴、過去に撮影した放射線画像等の患者に関する情報、撮影システム１６で用いられる、後述する電子カセッテ２０の識別番号（ＩＤ情報）、型式、サイズ、感度、使用開始年月日、使用回数等の電子カセッテ２０に関する情報、および電子カセッテ２０を用いて放射線画像を撮影する環境、すなわち、電子カセッテ２０を使用する環境（一例として、放射線撮影室や手術室等）を示す環境情報を含んで構成されている。 The database 14A was photographed in the patient's (subject's) attribute information (name, gender, date of birth, age, blood type, body weight, patient ID (Identification) etc.) as a subject, medical history, history of medical examination, in the past Information on the patient such as a radiation image, information on the electronic cassette 20 such as identification number (ID information) of the electronic cassette 20 described later, type, size, sensitivity, date of start of use, number of times of use, etc. And the environment which image | photographs a radiographic image using the electronic cassette 20, ie, the environment (for example, a radiography room, an operating room etc.) which uses the electronic cassette 20, is comprised including environmental information.
　なお、医療機関が管理する医療関連データをほぼ永久に保管し、必要なときに、必要な場所から瞬時に取り出すシステム（「医療クラウド」等と言う場合がある）を利用して、病院外のサーバーから、患者（被検者）の過去の個人情報等を入手するようにしてもよい。 In addition, outside the hospital using a system (sometimes referred to as a “medical cloud” etc.) where medical related data managed by a medical institution is stored almost permanently and taken out from the necessary place instantly when needed. Past personal information and the like of the patient (subject) may be obtained from the server.
　撮影システム１６は、ＲＩＳサーバー１４からの指示に応じて医師や放射線技師の操作により放射線画像の撮影を行う。撮影システム１６は、放射線照射制御ユニット２２（図４参照）の制御により放射線Ｘを照射する放射線照射源２２Ａから、照射条件に従った線量とされた放射線Ｘを被検者に照射する放射線発生装置２４と、被検者の撮影対象部位を透過した放射線Ｘを吸収して電荷を発生し、発生した電荷量に基づいて放射線画像を示す画像情報を生成する放射線検出器２６（図３参照）を内蔵する電子カセッテ２０と、電子カセッテ２０に内蔵されているバッテリを充電するクレードル２８と、電子カセッテ２０および放射線発生装置２４を制御するコンソール３０と、を備えている。 The imaging system 16 captures a radiation image by the operation of a doctor or a radiologist in accordance with an instruction from the RIS server 14. The imaging system 16 is a radiation generating apparatus that irradiates the subject with the radiation X, which is a dose according to the irradiation conditions, from the radiation irradiation source 22A that irradiates the radiation X under the control of the radiation irradiation control unit 22 (see FIG. 4) 24 and radiation detector 26 (see FIG. 3) that generates radiation by absorbing radiation X transmitted through the region to be imaged of the subject, and generates image information indicating a radiation image based on the generated charge amount. The electronic cassette 20 is provided, a cradle 28 for charging a battery incorporated in the electronic cassette 20, and a console 30 for controlling the electronic cassette 20 and the radiation generator 24.
　コンソール３０は、ＲＩＳサーバー１４からデータベース１４Ａに含まれる各種情報を取得して後述するＨＤＤ８８（図４参照。）に記憶し、必要に応じて当該情報を用いて、電子カセッテ２０および放射線発生装置２４の制御を行う。 The console 30 acquires various types of information included in the database 14A from the RIS server 14 and stores the information in the HDD 88 (see FIG. 4) described later, using the information as necessary to set the electronic cassette 20 and the radiation generator 24. Control the
　図２には、本実施の形態に係る撮影システム１６の放射線撮影室３２における各装置の配置状態の一例が示されている。 FIG. 2 shows an example of the arrangement of the devices in the radiation imaging room 32 of the imaging system 16 according to the present embodiment.
　図２に示される如く、放射線撮影室３２には、立位での放射線撮影を行う際に用いられる立位台３４と、臥位での放射線撮影を行う際に用いられる臥位台３６とが設置されており、立位台３４の前方空間は立位での放射線撮影を行う際の被検者３８の撮影位置とされ、臥位台３６の上方空間は臥位での放射線撮影を行う際の被検者４０の撮影位置とされている。 As shown in FIG. 2, in the radiography room 32, there are a standing table 34 used when performing radiation imaging in a standing position, and a holding platform 36 used when performing radiation imaging in a prone position. The space in front of the standing stand 34 is taken as the imaging position of the subject 38 at the time of radiographing in a standing position, and the space above the lying stand 36 is when radiographing in a lying position The shooting position of the test subject 40 is
　立位台３４には電子カセッテ２０を保持する保持部４２が設けられており、立位での放射線画像の撮影を行う際には、電子カセッテ２０が保持部４２に保持される。同様に、臥位台３６には電子カセッテ２０を保持する保持部４４が設けられており、臥位での放射線画像の撮影を行う際には、電子カセッテ２０が保持部４４に保持される。 The stand 34 is provided with a holder 42 for holding the electronic cassette 20, and the electronic cassette 20 is held by the holder 42 when a radiation image is taken in the standing position. Similarly, a holding unit 44 for holding the electronic cassette 20 is provided on the holding base 36, and the electronic cassette 20 is held by the holding unit 44 when the radiation image is taken in the lying position.
　また、放射線撮影室３２には、単一の放射線照射源２２Ａからの放射線によって立位での放射線撮影も臥位での放射線撮影も可能とするために、放射線照射源２２Ａを、水平な軸回り（図２の矢印Ａ方向）に回動可能に、鉛直方向（図２の矢印Ｂ方向）に移動可能に、さらに水平方向（図２の矢印Ｃ方向）に移動可能に支持する支持移動機構４６が設けられている。この図２の矢印Ａ～Ｃ方向へ放射線照射源２２Ａを移動（回動を含む）させる駆動源は、支持移動機構４６に内蔵されており、ここでは、図示を省略する。 In addition, in the radiography room 32, the radiation irradiation source 22A is turned around a horizontal axis so that radiography in a standing position and radiography in a recumbent position are also possible by radiation from a single radiation irradiation source 22A. A supporting and moving mechanism 46 for movably supporting in the vertical direction (direction of arrow B in FIG. 2) and movable in the horizontal direction (direction of arrow C in FIG. 2) so as to be rotatable in the direction of arrow A in FIG. Is provided. A drive source for moving (including rotating) the radiation irradiation source 22A in the directions of arrows A to C in FIG. 2 is incorporated in the support moving mechanism 46, and is not shown here.
　一方、クレードル２８には、電子カセッテ２０を収納可能な収容部２８Ａが形成されている。 On the other hand, the cradle 28 is formed with a housing portion 28A capable of housing the electronic cassette 20.
　電子カセッテ２０は、未使用時にはクレードル２８の収容部２８Ａに収納された状態で内蔵されているバッテリに充電が行われ、放射線画像の撮影時には放射線技師等によってクレードル２８から取り出され、撮影姿勢が立位であれば立位台３４の保持部４２に保持され、撮影姿勢が臥位であれば臥位台３６の保持部４４に保持される。 When the electronic cassette 20 is not in use, the battery contained in the housing 28A of the cradle 28 is charged, and when taking a radiation image, the electronic cassette 20 is taken out of the cradle 28 by a radiologist etc. If the photographing position is the recumbent position, the image is held by the holding portion 44 of the holding base 36.
　ここで、本実施の形態に係る撮影システム１６では、図４に示される如く、放射線発生装置２４とコンソール３０との間、および電子カセッテ２０とコンソール３０との間で、無線通信によって各種情報の送受信を行う（詳細後述）。 Here, in the imaging system 16 according to the present embodiment, as shown in FIG. 4, various types of information are communicated by wireless communication between the radiation generating device 24 and the console 30 and between the electronic cassette 20 and the console 30. Send and receive (details will be described later).
　なお、電子カセッテ２０は、立位台３４の保持部４２や臥位台３６の保持部４４で保持された状態のみで使用されるものではなく、その可搬性から、腕部，脚部等を撮影する際には、保持部に保持されていない状態で使用することもできる。 The electronic cassette 20 is not used only in a state of being held by the holding portion 42 of the standing base 34 and the holding portion 44 of the recumbent base 36, but from the viewpoint of its portability, the arms, legs, etc. When taking a picture, it can be used in a state where it is not held by the holding unit.
　図３は、電子カセッテ２０に装備される放射線検出器２６の３画素部分の構成を概略的に示す断面模式図である。 FIG. 3 is a schematic cross-sectional view schematically showing the configuration of three pixel portions of the radiation detector 26 provided in the electronic cassette 20. As shown in FIG.
　図３に示される如く、放射線検出器２６は、絶縁性の基板５０上に、信号出力部５２、センサ部５４（ＴＦＴ基板７４）、およびシンチレータ５６が順次積層しており、信号出力部５２およびセンサ部５４によりＴＦＴ基板７４の画素群が構成されている。すなわち、複数の画素は、基板５０上にマトリクス状に配列されており、各画素における信号出力部５２とセンサ部５４とが重なりを有するように構成されている。なお、信号出力部５２とセンサ部５４との間には、絶縁膜５３が介在されている。 As shown in FIG. 3, in the radiation detector 26, the signal output unit 52, the sensor unit 54 (the TFT substrate 74), and the scintillator 56 are sequentially stacked on the insulating substrate 50. The sensor unit 54 constitutes a pixel group of the TFT substrate 74. That is, the plurality of pixels are arranged in a matrix on the substrate 50, and the signal output unit 52 and the sensor unit 54 in each pixel are configured to have an overlap. An insulating film 53 is interposed between the signal output unit 52 and the sensor unit 54.
　シンチレータ５６は、センサ部５４上に透明絶縁膜５８を介して形成されており、上方（基板５０の反対側）または下方から入射してくる放射線を光に変換して発光する蛍光体を成膜したものである。このようなシンチレータ５６を設けることで、被写体を透過した放射線を吸収して発光することになる。 The scintillator 56 is formed on the sensor unit 54 via the transparent insulating film 58, and forms a film of a phosphor which converts radiation incident from the upper side (the opposite side of the substrate 50) or the lower side into light and emits light. It is By providing such a scintillator 56, the radiation transmitted through the subject is absorbed and emitted.
　シンチレータ５６が発する光の波長域は、可視光域（波長３６０ｎｍ～８３０ｎｍ）であることが好ましく、この放射線検出器２６によってモノクロ撮像を可能とするためには、緑色の波長域を含んでいることがより好ましい。 The wavelength range of light emitted by the scintillator 56 is preferably a visible light range (wavelength 360 nm to 830 nm), and in order to enable monochrome imaging by this radiation detector 26, it includes a green wavelength range. Is more preferred.
　シンチレータ５６に用いる蛍光体としては、具体的には、放射線としてＸ線を用いて撮像する場合、ヨウ化セシウム（ＣｓＩ）を含むものが好ましく、Ｘ線照射時の発光スペクトルが４００ｎｍ～７００ｎｍにあるＣｓＩ（Ｔｌ）（タリウムが添加されたヨウ化セシウム）を用いることが特に好ましい。なお、ＣｓＩ（Ｔｌ）の可視光域における発光ピーク波長は５６５ｎｍである。 Specifically, in the case of imaging using X-ray as radiation, the phosphor used for the scintillator 56 preferably contains cesium iodide (CsI), and the emission spectrum at the time of X-ray irradiation is in the range of 400 nm to 700 nm It is particularly preferred to use CsI (Tl) (cesium iodide to which thallium is added). The emission peak wavelength of CsI (Tl) in the visible light range is 565 nm.
　センサ部５４は、上部電極６０、下部電極６２、および当該上下の電極間に配置された光電変換膜６４を有する。光電変換膜６４は、シンチレータ５６が発する光を吸収して電荷が発生する有機光電変換材料により構成されている。 The sensor unit 54 includes an upper electrode 60, a lower electrode 62, and a photoelectric conversion film 64 disposed between the upper and lower electrodes. The photoelectric conversion film 64 is made of an organic photoelectric conversion material that absorbs light emitted by the scintillator 56 to generate charges.
　上部電極６０は、シンチレータ５６により生じた光を光電変換膜６４に入射させる必要があるため、少なくともシンチレータ５６の発光波長に対して透明な導電性材料で構成することが好ましく、具体的には、可視光に対する透過率が高く、抵抗値が小さい透明導電性酸化物（TCO：Transparent Conducting Oxide）を用いることが好ましい。なお、上部電極６０としてＡｕなどの金属薄膜を用いることもできるが、透過率を９０％以上得ようとすると抵抗値が増大し易いため、ＴＣＯの方が好ましい。例えば、ＩＴＯ、ＩＺＯ、ＡＺＯ、ＦＴＯ、ＳｎＯ２、ＴｉＯ２、ＺｎＯ２等を好ましく用いることができ、プロセス簡易性、低抵抗性、透明性の観点からはＩＴＯが最も好ましい。なお、上部電極６０は、全画素で共通の一枚構成としてもよく、画素毎に分割してもよい。 The upper electrode 60 is preferably made of a conductive material that is transparent to at least the light emission wavelength of the scintillator 56 because the light generated by the scintillator 56 needs to be incident on the photoelectric conversion film 64, specifically, It is preferable to use a transparent conductive oxide (TCO) having a high transmittance to visible light and a small resistance value. Although a metal thin film of Au or the like can be used as the upper electrode 60, TCO is preferable because the resistance value tends to increase if it is desired to obtain a transmittance of 90% or more. For example, ITO, IZO, AZO, FTO, SnO 2 , TiO 2 , ZnO 2 and the like can be preferably used, and ITO is most preferable from the viewpoint of process simplicity, low resistance, and transparency. Note that the upper electrode 60 may be configured as a single sheet common to all the pixels, or may be divided for each pixel.
　光電変換膜６４は、有機光電変換材料を含み、シンチレータ５６から発せられた光を吸収し、吸収した光に応じた電荷を発生する。このように有機光電変換材料を含む光電変換膜６４であれば、可視域にシャープな吸収スペクトルを持ち、シンチレータ５６による発光以外の電磁波が光電変換膜６４に吸収されることがほとんどなく、Ｘ線等の放射線が光電変換膜６４で吸収されることによって発生するノイズを効果的に抑制することができる。 The photoelectric conversion film 64 contains an organic photoelectric conversion material, absorbs light emitted from the scintillator 56, and generates a charge according to the absorbed light. As described above, the photoelectric conversion film 64 containing the organic photoelectric conversion material has a sharp absorption spectrum in the visible region, and electromagnetic waves other than the light emitted by the scintillator 56 are hardly absorbed by the photoelectric conversion film 64, and X-rays The noise generated by the absorption of radiation such as by the photoelectric conversion film 64 can be effectively suppressed.
　光電変換膜６４を構成する有機光電変換材料は、シンチレータ５６で発光した光を最も効率よく吸収するために、その吸収ピーク波長が、シンチレータ５６の発光ピーク波長と近いほど好ましい。有機光電変換材料の吸収ピーク波長とシンチレータ５６の発光ピーク波長とが一致することが理想的であるが、双方の差が小さければシンチレータ５６から発された光を十分に吸収することが可能である。具体的には、有機光電変換材料の吸収ピーク波長と、シンチレータ５６の放射線に対する発光ピーク波長との差が、１０ｎｍ以内であることが好ましく、５ｎｍ以内であることがより好ましい。 It is preferable that the absorption peak wavelength of the organic photoelectric conversion material forming the photoelectric conversion film 64 be closer to the emission peak wavelength of the scintillator 56 in order to absorb the light emitted by the scintillator 56 most efficiently. Ideally, the absorption peak wavelength of the organic photoelectric conversion material matches the emission peak wavelength of the scintillator 56, but if the difference between the two is small, it is possible to sufficiently absorb the light emitted from the scintillator 56. . Specifically, the difference between the absorption peak wavelength of the organic photoelectric conversion material and the emission peak wavelength of radiation of the scintillator 56 is preferably 10 nm or less, and more preferably 5 nm or less.
　このような条件を満たすことが可能な有機光電変換材料としては、例えばキナクリドン系有機化合物およびフタロシアニン系有機化合物が挙げられる。例えばキナクリドンの可視域における吸収ピーク波長は５６０ｎｍであるため、有機光電変換材料としてキナクリドンを用い、シンチレータ５６の材料としてＣｓＩ（Ｔｌ）を用いれば、上記ピーク波長の差を５ｎｍ以内にすることが可能となり、光電変換膜６４で発生する電荷量をほぼ最大にすることができる。 As an organic photoelectric conversion material which can satisfy such conditions, a quinacridone organic compound and a phthalocyanine organic compound are mentioned, for example. For example, since the absorption peak wavelength of quinacridone in the visible region is 560 nm, the difference between the peak wavelengths can be made within 5 nm by using quinacridone as the organic photoelectric conversion material and CsI (Tl) as the material of the scintillator 56 Thus, the amount of charge generated in the photoelectric conversion film 64 can be substantially maximized.
　各画素を構成するセンサ部５４は、少なくとも下部電極６２、光電変換膜６４、および上部電極６０を含んでいればよいが、暗電流の増加を抑制するため、電子ブロッキング膜６６および正孔ブロッキング膜６８の少なくともいずれかを設けることが好ましく、両方を設けることがより好ましい。 The sensor unit 54 constituting each pixel may include at least the lower electrode 62, the photoelectric conversion film 64, and the upper electrode 60. However, in order to suppress an increase in dark current, the electron blocking film 66 and the hole blocking film It is preferable to provide at least one of 68, and it is more preferable to provide both.
　電子ブロッキング膜６６は、下部電極６２と光電変換膜６４との間に設けることができ、下部電極６２と上部電極６０間にバイアス電圧を印加したときに、下部電極６２から光電変換膜６４に電子が注入されて暗電流が増加してしまうのを抑制することができる。電子ブロッキング膜６６には、電子供与性有機材料を用いることができる。 The electron blocking film 66 can be provided between the lower electrode 62 and the photoelectric conversion film 64, and when a bias voltage is applied between the lower electrode 62 and the upper electrode 60, the electrons from the lower electrode 62 to the photoelectric conversion film 64 Can be suppressed to increase the dark current. For the electron blocking film 66, an electron donating organic material can be used.
　正孔ブロッキング膜６８は、光電変換膜６４と上部電極６０との間に設けることができ、下部電極６２と上部電極６０間にバイアス電圧を印加したときに、上部電極６０から光電変換膜６４に正孔が注入されて暗電流が増加してしまうのを抑制することができる。正孔ブロッキング膜６８には、電子受容性有機材料を用いることができる。 The hole blocking film 68 can be provided between the photoelectric conversion film 64 and the upper electrode 60, and when a bias voltage is applied between the lower electrode 62 and the upper electrode 60, the upper electrode 60 to the photoelectric conversion film 64. It is possible to suppress an increase in dark current due to the injection of holes. For the hole blocking film 68, an electron accepting organic material can be used.
　信号出力部５２は、下部電極６２に対応して、下部電極６２に移動した電荷を蓄積するコンデンサ７０と、コンデンサ７０に蓄積された電荷を電気信号に変換して出力する電界効果型薄膜トランジスタ（Thin Film Transistor、以下、単に薄膜トランジスタという場合がある。）７２が形成されている。コンデンサ７０および薄膜トランジスタ７２の形成された領域は、平面視において下部電極６２と重なる部分を有しており、このような構成とすることで、各画素における信号出力部５２とセンサ部５４とが厚さ方向で重なりを有することとなる。なお、放射線検出器２６（画素）の平面積を最小にするために、コンデンサ７０および薄膜トランジスタ７２の形成された領域が下部電極６２によって完全に覆われていることが望ましい。 The signal output unit 52 corresponds to the lower electrode 62, a capacitor 70 for storing the charge transferred to the lower electrode 62, and a field effect thin film transistor (Thin for converting the charge stored in the capacitor 70 into an electric signal and outputting it. In the following, the film transistor may be simply referred to as a thin film transistor) 72 is formed. The region where the capacitor 70 and the thin film transistor 72 are formed has a portion overlapping the lower electrode 62 in a plan view, and with such a configuration, the signal output portion 52 and the sensor portion 54 in each pixel are thick. It will have an overlap in the longitudinal direction. In order to minimize the planar area of the radiation detector 26 (pixel), it is desirable that the region in which the capacitor 70 and the thin film transistor 72 are formed be completely covered by the lower electrode 62.
　図４は、本実施の形態に係る撮影システム１６の制御ブロック図である。 FIG. 4 is a control block diagram of the imaging system 16 according to the present embodiment.
　コンソール３０は、サーバー・コンピュータとして構成されており、操作メニューや撮影された放射線画像等を表示するディスプレイ８０と、複数のキーを含んで構成され、各種の情報や操作指示が入力される操作パネル８２と、を備えている。 The console 30 is configured as a server computer, and includes an operation menu and a display 80 for displaying a captured radiation image and the like, and a plurality of keys, and an operation panel on which various information and operation instructions are input. And 82.
　また、本実施の形態に係るコンソール３０は、装置全体の動作を司るＣＰＵ８４と、制御プログラムを含む各種プログラム等が予め記憶されたＲＯＭ８６と、各種データを一時的に記憶するＲＡＭ８７と、各種データを記憶して保持するＨＤＤ（ハードディスク・ドライブ）８８と、ディスプレイ８０への各種情報の表示を制御するディスプレイドライバ９２と、操作パネル８２に対する操作状態を検出する操作入力検出部９０と、を備えている。 In addition, the console 30 according to the present embodiment includes a CPU 84 for controlling the operation of the entire apparatus, a ROM 86 in which various programs including control programs are stored in advance, a RAM 87 for temporarily storing various data, and various data. An HDD (hard disk drive) 88 that stores and holds, a display driver 92 that controls the display of various information on the display 80, and an operation input detection unit 90 that detects an operation state of the operation panel 82. .
　また、コンソール３０は、無線通信により、画像処理装置２３及び放射線発生装置２４との間で後述する照射条件等の各種情報の送受信を行い、且つ、電子カセッテ２０との間で画像データ等の各種情報の送受信を行うＩ／Ｆ（例えば、無線通信部）９６及びＩ／Ｏ９４を備えている。 The console 30 transmits and receives various information such as irradiation conditions to be described later to and from the image processing device 23 and the radiation generation device 24 by wireless communication, and various types of image data and the like to and from the electronic cassette 20. An I / F (for example, a wireless communication unit) 96 and an I / O 94 that transmit and receive information are provided.
　ＣＰＵ８４、ＲＯＭ８６、ＲＡＭ８７、ＨＤＤ８８、ディスプレイドライバ９２、操作入力検出部９０、Ｉ／Ｏ９４、および無線通信部９６は、システムバスやコントロールバス等のバス９８を介して相互に接続されている。従って、ＣＰＵ８４は、ＲＯＭ８６、ＲＡＭ８７、ＨＤＤ８８へのアクセスを行うことができ、ディスプレイドライバ９２を介したディスプレイ８０への各種情報の表示の制御、および無線通信部９６を介した放射線発生装置２４および電子カセッテ２０との各種情報の送受信の制御を各々行うことができる。また、ＣＰＵ８４は、操作入力検出部９０を介して操作パネル８２に対するユーザの操作状態を把握することができる。 The CPU 84, the ROM 86, the RAM 87, the HDD 88, the display driver 92, the operation input detection unit 90, the I / O 94, and the wireless communication unit 96 are mutually connected via a bus 98 such as a system bus or control bus. Therefore, the CPU 84 can access the ROM 86, the RAM 87, and the HDD 88, controls the display of various information on the display 80 via the display driver 92, and the radiation generator 24 and the electronics via the wireless communication unit 96. Control of transmission and reception of various information with the cassette 20 can be performed respectively. In addition, the CPU 84 can grasp the operation state of the user on the operation panel 82 through the operation input detection unit 90.
　一方、画像処理装置２３は、コンソール３０との間で照射条件等の各種情報を送受信するＩ／Ｆ（例えば無線通信部）１００と、照射条件に基づいて、電子カセッテ２０及び放射線発生装置２４を制御する画像処理制御ユニット１０２と、を備えている。また、放射線発生装置２４は、放射線照射源２２Ａからの放射線照射を制御する放射線照射制御ユニット２２を備えている。 On the other hand, the image processing device 23 transmits and receives various information such as irradiation conditions to and from the console 30 (for example, a wireless communication unit) 100, and the electronic cassette 20 and the radiation generator 24 based on the irradiation conditions. And an image processing control unit 102 for controlling. The radiation generator 24 also includes a radiation irradiation control unit 22 that controls the radiation irradiation from the radiation irradiation source 22A.
　画像処理制御ユニット１０２は、システム制御部１０４、パネル制御部１０６、および画像処理制御部１０８を備え、相互にバス１１０によって情報をやりとりしている。パネル制御部１０６では、前記電子カセッテ２０からの情報を、無線又は有線により受け付け、画像処理制御部１０８で画像処理が施される。 The image processing control unit 102 includes a system control unit 104, a panel control unit 106, and an image processing control unit 108, and exchanges information with each other via a bus 110. The panel control unit 106 receives information from the electronic cassette 20 wirelessly or by wire, and the image processing control unit 108 performs image processing.
　一方、システム制御部１０４は、コンソール３０から照射条件には管電圧、管電流等の情報を受信し、受信した照射条件に基づいて放射線照射制御ユニット２２の放射線照射源２２Ａから放射線Ｘを照射させる制御を行う。 On the other hand, the system control unit 104 receives information such as tube voltage and tube current under the irradiation conditions from the console 30, and causes the radiation X to be irradiated from the radiation irradiation source 22A of the radiation irradiation control unit 22 based on the received irradiation conditions. Take control.
　ところで、放射線画像を撮影するにあたり、全撮影領域に対して、注目するべき領域（関心領域）が限定される場合がある。例えば、特に動画撮影の場合、ほぼ静止している臓器や骨格が注目される画像である場合は少ない。言い換えれば、例えば、心臓等、鼓動している臓器、或いは、血管内を案内されて移動するカテーテル管等が注目される画像である場合が多い。 By the way, when imaging a radiation image, an area to be noted (area of interest) may be limited with respect to the entire imaging area. For example, particularly in the case of moving image shooting, there are few cases in which an almost stationary organ or skeleton is an image of interest. In other words, for example, a heart beating organ or a catheter tube guided and moved in a blood vessel is often an image of interest.
　このため、本実施の形態における、撮影システム１６では、撮影画像の動作状態に基づいて、自動的に関心領域を設定する機能を備えており、撮影指示があると、放射線画像撮影準備制御の後、関心領域（以下、「ＲＯＩ」という場合がある）を設定するための制御が実行されるようになっている。なお、表示された画像を指示することにより手動でＲＯＩを設定するようにしてもよい。 Therefore, in the present embodiment, the imaging system 16 has a function of automatically setting the region of interest based on the operation state of the captured image, and when there is an instruction to perform imaging, after radiation image imaging preparation control Control for setting a region of interest (hereinafter sometimes referred to as “ROI”) is performed. The ROI may be manually set by designating the displayed image.
　また、本実施の形態の撮影システム１６では、ＡＢＣ「Auto Brightness Control」制御によって、被検者への放射線の放射線量をフィードバック補正して、適正な画像情報を得ることがなされている。この場合、撮影初期では、実際に照射される放射線量と、適正な画像情報を得るための放射線量との間に大きな開きがあると、振幅の激しいフィードバック制御が繰り返され、徐々に収束していくため、収束するまでは放射線量の増減によってディスプレイ８０の表示画面がちらつくので目の疲れにつながる。 Further, in the imaging system 16 according to the present embodiment, the radiation dose of the radiation to the subject is feedback-corrected by ABC “Auto Brightness Control” control to obtain appropriate image information. In this case, if there is a large difference between the actually irradiated radiation dose and the radiation dose for obtaining appropriate image information in the initial stage of imaging, the feedback control of the amplitude is repeated repeatedly and gradually converges. Because the display screen of the display 80 flickers due to the increase and decrease of the radiation dose until convergence, it leads to eye fatigue.
　そこで、本実施の形態では、ＡＢＣ制御の際の画像のちらつきを軽減するために、非関心領域を抽出して、非関心領域における階調信号（以下、ＱＬ値という場合がある）の変化度合が小さくなるようにしている。なお、ＱＬ値は、放射線を照射して得られた放射線画像のフィルムの濃度に相当する値であり、階調信号そのものであってもよいし、階調信号に対して所定の処理を行った信号であってもよい。 Therefore, in the present embodiment, in order to reduce the flickering of the image at the time of ABC control, the non-interest region is extracted, and the degree of change of the gradation signal (hereinafter sometimes referred to as QL value) in the non-interest region To make it smaller. Note that the QL value is a value corresponding to the film density of a radiation image obtained by irradiating radiation, and may be a gray scale signal itself, or a predetermined process was performed on the gray scale signal. It may be a signal.
　図５は、撮影システム１６（主として、電子カセッテ２０、コンソール３０、画像処理装置２３、放射線発生装置２４）における、放射線画像撮影（ＲＯＩ設定を含む）のための制御系に特化した機能ブロック図である。なお、このブロック図は、放射線画像撮影制御を機能別に分類したものであり、ハードウェア構成を限定するものではない。 FIG. 5 is a functional block diagram specialized in a control system for radiation image capturing (including ROI setting) in the imaging system 16 (mainly, the electronic cassette 20, the console 30, the image processing device 23, the radiation generating device 24). It is. Note that this block diagram is a classification of radiation imaging control by function, and does not limit the hardware configuration.
　撮影システム１６は、図５に示すように、放射線量照射制御ユニット２２、放射線量調整部１２０、ＴＦＴ基板７４、階調信号取得部１２２、階調信号調整部１２４、関心領域（ＲＯＩ）設定部１３８、関心領域抽出部１４０、非関心領域抽出部１２６、静止画像生成部１２８、動画編集部１３０、ディスプレイドライバ９２、ディスプレイ８０、平均ＱＬ値演算部１３２、ＡＢＣ制御部１３４、及び基準ＱＬ値メモリ１３６の機能を有する。 As shown in FIG. 5, the imaging system 16 includes a radiation dose irradiation control unit 22, a radiation dose adjustment unit 120, a TFT substrate 74, a gradation signal acquisition unit 122, a gradation signal adjustment unit 124, and a region of interest (ROI) setting unit 138, region of interest extraction unit 140, non-interest region extraction unit 126, still image generation unit 128, moving image editing unit 130, display driver 92, display 80, average QL value calculation unit 132, ABC control unit 134, and reference QL value memory It has 136 functions.
　放射線照射制御ユニット２２では、放射線量調整部１２０によって調整された放射線量に基づいて、放射線照射源２２Ａから放射線を照射する。 The radiation irradiation control unit 22 irradiates radiation from the radiation irradiation source 22A based on the radiation dose adjusted by the radiation dose adjusting unit 120.
　放射線照射制御ユニット２２から被験者に照射された放射線は、被験者を透過して電子カセッテ２０の放射線検出器２６（図３参照）へ至るようになっている。放射線検出器２６では、蛍光体膜５６（図３参照）によって放射線量に応じた光量の光で発光し、ＴＦＴ基板７４によって光電変換されて階調信号が生成される。 The radiation emitted from the radiation control unit 22 to the subject passes through the subject and reaches the radiation detector 26 (see FIG. 3) of the electronic cassette 20. In the radiation detector 26, the phosphor film 56 (see FIG. 3) emits light with a light amount corresponding to the radiation amount, and is photoelectrically converted by the TFT substrate 74 to generate a gradation signal.
　階調信号取得部１２２では、ＴＦＴ基板７４によって生成された階調信号を取得して階調信号調整部１２４へ送出する。なお、この光電変換信号は、アナログ信号であってもよいし、電子カセッテ２０内の制御部において、デジタル信号に変換した後の信号であってもよい。 The gradation signal acquisition unit 122 acquires the gradation signal generated by the TFT substrate 74 and sends the gradation signal to the gradation signal adjustment unit 124. The photoelectric conversion signal may be an analog signal or may be a signal after being converted into a digital signal by the control unit in the electronic cassette 20.
　階調信号調整部１２４では、ＡＢＣ制御による階調信号（ＱＬ値）の変化度合が、関心領域（ＲＯＩ）設定部１３８によって設定された関心領域の階調信号の変化度合よりも非関心領域の変化度合の方が小さくなるように、階調信号の調整を行う。例えば、本実施の形態では、非関心領域の階調信号の下位ビットを予め定めた値（例えば、「０」又は「１」）に固定することにより、非関心領域の変化度合を小さくする。 In the gradation signal adjustment unit 124, the change degree of the gradation signal (QL value) due to ABC control is lower than the change degree of the gradation signal of the region of interest set by the region of interest (ROI) setting unit 138. The gradation signal is adjusted so that the degree of change is smaller. For example, in the present embodiment, the degree of change of the non-interest region is reduced by fixing the lower bits of the gradation signal of the non-interest region to a predetermined value (for example, “0” or “1”).
　静止画像生成部１２８では、１フレーム分の階調信号に基づいて静止画像を順次生成する。なお、動画像撮影の場合と静止画撮影の場合とでは、電子カセッテ２０から送られる光電変換信号そのものが異なり、例えば、本実施の形態のように、動画像撮影の場合には、転送速度を優先するため、ビニング処理がなされる。一方、仮に、静止画撮影をする場合には、画質を優先するため、ＴＦＴ基板７４における最大の画素数に基づく画像データが生成される。 The still image generation unit 128 sequentially generates still images based on the gradation signal of one frame. Note that the photoelectric conversion signal itself sent from the electronic cassette 20 differs between moving image shooting and still image shooting, and for example, in the case of moving image shooting as in the present embodiment, the transfer speed is set. A binning process is performed to give priority. On the other hand, when taking a still image, image data based on the maximum number of pixels in the TFT substrate 74 is generated in order to give priority to the image quality.
　動画編集部１３０では、静止画像生成部１２８によって生成された１フレーム毎の画像データを組み合わせて動画編集を行う。編集された動画像は、ディスプレイドライバ９２を介してディスプレイ８０に表示されるようになっている。なお、静止画を表する場合には、静止画像生成部１２８によって生成された静止画がディスプレイドライバ９２を介してディスプレイ８０に表示されるようになっている。 The moving image editing unit 130 performs moving image editing by combining the image data of each frame generated by the still image generating unit 128. The edited moving image is displayed on the display 80 via the display driver 92. In the case of representing a still image, the still image generated by the still image generation unit 128 is displayed on the display 80 via the display driver 92.
　また、関心領域（ＲＯＩ）設定部１３８では、パターンマッチングや、移動量が大きい領域の検出などを行うことにより、関心領域を設定する。なお、ユーザの操作によって関心領域を設定するようにしてもよい。 In addition, a region of interest (ROI) setting unit 138 sets a region of interest by performing pattern matching, detecting a region having a large amount of movement, and the like. The region of interest may be set by the user's operation.
　非関心領域抽出部１２６では、関心領域（ＲＯＩ）設定部１３８によって設定された関心領域に基づいて、非関心領域の部分を抽出し、関心領域抽出部１４０では、関心領域（ＲＯＩ）設定部１３８によって設定された関心領域の部分を抽出する。 The non-interest region extraction unit 126 extracts a portion of the non-interest region based on the region of interest set by the region of interest (ROI) setting unit 138, and the region of interest extraction unit 140 sets the region of interest (ROI) setting unit 138. Extract the part of the region of interest set by.
　平均ＱＬ値演算部１３２では、動画像の各フレーム（或いは、適宜抜き取った１フレーム）における関心領域のＱＬ値の平均値を演算する。平均値ＱＬ値演算部１３２の演算結果は、ＡＢＣ制御部１３４へ送出されるようになっている。 The average QL calculation unit 132 calculates the average value of the QL values of the region of interest in each frame (or one frame appropriately extracted) of the moving image. The calculation result of the average value QL value calculation unit 132 is sent to the ABC control unit 134.
　ＡＢＣ制御部１３４では、平均ＱＬ値演算部１３２によって演算されたＱＬ平均値と、基準ＱＬ値メモリ１３６に格納された基準ＱＬ値とを比較して、ＱＬ平均値を基準ＱＬ値に収束させるための補正情報ΔＸを生成する。この補正情報ΔＸは、放射線照射源２２Ａから照射される放射線量（放射線エネルギー）を増減させるための補正係数として適用される。 The ABC control unit 134 compares the QL average value calculated by the average QL value calculation unit 132 with the reference QL value stored in the reference QL value memory 136 to converge the QL average value to the reference QL value. Correction information .DELTA.X is generated. The correction information ΔX is applied as a correction coefficient to increase or decrease the radiation dose (radiation energy) emitted from the radiation irradiation source 22A.
　ＡＢＣ制御部１３４で生成された補正情報ΔＸは、放射線量調整部１２０へ送出される。放射線量調整部１２０では、補正情報ΔＸに基づいて放射線量ＸＮを増減させる（ＸＮ←ＸＮ×ΔＸ）。すなわち、放射線量調整部１２０は、照射指示があった時点では、予め定めた初期値から照射を開始し、その後、補正情報ΔＸに基づいて放射線量を増減して、基準ＱＬ値になるように補正する。なお、本実施の形態では、放射線量ＸＮの補正の際、補正情報ΔＸを乗（除）算の係数としたが、加（減）算係数（ＸＮ←ＸＮ＋ΔＸＮ）としてもよい。 The correction information ΔX generated by the ABC control unit 134 is sent to the radiation dose adjustment unit 120. The radiation dose adjustment unit 120 increases or decreases the radiation dose XN based on the correction information ΔX (XN ← XN × ΔX). That is, at the time when the radiation instruction is issued, the radiation dose adjustment unit 120 starts radiation from a predetermined initial value, and thereafter increases or decreases the radiation dose based on the correction information ΔX to become the reference QL value. to correct. In the present embodiment, at the time of correction of the radiation dose XN, the correction information ΔX is used as a coefficient for multiplication (division), but may be an addition (subtraction) coefficient (XNXXN + ΔXN).
　なお、本実施の形態では、１フレームのＱＬ値の平均値が基準ＱＬ値になるようにＡＢＣ制御部１３４によって放射線量を補正するものとして説明するが、ＡＢＣ制御部１３４は、少なくとも１フレームの静止画像情報の一部における階調信号の平均値に代表される演算値が予め定めた範囲の値になるように放射線量を補正するようにしてもよい。例えば、ＡＢＣ制御部１３４は、１フレームの階調信号の発生頻度をヒストグラム（例えば、横軸を階調信号とし、縦軸をその発生頻度としたヒストグラム）にしたときに、発生頻度が最大の階調（或いは最大の階調を含む所定の範囲の階調）が予め定めた範囲の値に収まるように放射線量を補正するようにしてもよいし、１フレームの静止画像情報の一部における階調信号の平均値以外の他の演算値（階調信号の加算値等）が予め定めた値（又は予め定めた範囲の値）になるように放射線量を補正するようにしてもよい。演算値として階調信号の加算値を用いる場合、例えば、１フレームの静止画像情報における階調信号に対して対応する画素位置等に応じて重み付けを行い、重み付け後の階調信号を加算した値を用いてもよい。重み付けは、関心領域（ＲＯＩ）の中央部において重み付け係数を高くし、周辺部に向かうに従って重み付け係数を低くするものであってもよく、この重み付け係数の設定は段階的（例えば２段階等）であっても、関数により定義された連続的に変化するものであってもよい。 In the present embodiment, although it is described that the radiation amount is corrected by the ABC control unit 134 so that the average value of the QL values of one frame becomes the reference QL value, the ABC control unit 134 corrects the radiation amount. The radiation dose may be corrected so that the operation value represented by the average value of the gradation signals in a part of the still image information becomes a value in a predetermined range. For example, when the ABC control unit 134 sets the occurrence frequency of the gradation signal of one frame to a histogram (for example, a histogram in which the horizontal axis is the gradation signal and the vertical axis is the occurrence frequency), the occurrence frequency is maximum. The radiation dose may be corrected so that the gray level (or the gray level within a predetermined range including the maximum gray level) falls within a predetermined range of values, or in part of still image information of one frame. The radiation dose may be corrected such that another calculated value (addition value of the gradation signal, etc.) other than the average value of the gradation signal becomes a predetermined value (or a value in a predetermined range). When using the addition value of the gradation signal as the operation value, for example, weighting is performed according to the pixel position corresponding to the gradation signal in still image information of one frame, and the value obtained by adding the weighted gradation signal May be used. The weighting may be to increase the weighting factor in the center of the region of interest (ROI) and lower the weighting factor toward the periphery, and setting of the weighting factor is stepwise (for example, in two stages) It may be continuous or it may be defined by a function.
　ここで、上述の階調信号調整部１２４について更に詳細に説明する。図６は、階調信号調整部１２４の詳細な機能を示す機能ブロック図である。 Here, the above-mentioned gradation signal adjustment unit 124 will be described in more detail. FIG. 6 is a functional block diagram showing the detailed function of the gradation signal adjustment unit 124. As shown in FIG.
　階調信号調整部１２４は、図６に示すように、階調信号受付部１５０、調整前階調信号フレームメモリ１５２、座標（ｘ、ｙ）画素抽出部１５４、非関心領域画像階調信号メモリ１５６、座標（ｘ、ｙ）抽出部１５８、照合部１６０、下位ビット調整処理部１６２、下位ビットデータメモリ１６４、調整後階調信号フレームメモリ１６６、及び階調信号送出部１６８の機能を有する。 As shown in FIG. 6, the gradation signal adjustment unit 124 includes the gradation signal reception unit 150, the adjustment gradation signal frame memory 152, the coordinates (x, y) pixel extraction unit 154, and the non-interest region image gradation signal memory. A function of the coordinate (x, y) extraction unit 158, the collation unit 160, the lower bit adjustment processing unit 162, the lower bit data memory 164, the adjusted gradation signal frame memory 166, and the gradation signal transmission unit 168 is provided.
　階調信号受付部１５０では、階調信号取得部１２２によって取得した階調信号を受け付け、調整前階調信号フレームメモリ１５２に格納する。 The gradation signal reception unit 150 receives the gradation signal acquired by the gradation signal acquisition unit 122 and stores the gradation signal in the pre-adjustment gradation signal frame memory 152.
　座標（ｘ、ｙ）抽出部１５４では、調整前階調信号フレームメモリ１５２に格納された階調信号を座標毎に順次取り出して、照合部１６０へ送出する。 The coordinate (x, y) extraction unit 154 sequentially extracts the gradation signal stored in the pre-adjustment gradation signal frame memory 152 for each coordinate, and sends it to the collation unit 160.
　また、非関心領域抽出部１２６によって抽出された非関心領域の階調信号を非関心領域画像階調信号メモリ１５６に一旦格納する。 Also, the grayscale signal of the non-interest region extracted by the non-interest region extraction unit 126 is temporarily stored in the non-interest region image grayscale signal memory 156.
　座標（ｘ、ｙ）抽出部１５８では、非関心領域画像階調信号メモリ１５６に格納された非関心領域画像を座標毎に順次取り出して照合部１６０へ送出する。 The coordinate (x, y) extraction unit 158 sequentially extracts the non-interest region images stored in the non-interest region image tone signal memory 156 for each coordinate and sends the non-interest region images to the collation unit 160.
　照合部１６０では、非関心領域画像の画素か否かを判断して、非関心領域画像の階調信号については下位ビット調整処理部１６２へ送出し、関心領域の画像階調信号については調整不要画素階調信号としてそのまま調整後階調信号フレームメモリ１６６に格納する。 The collation unit 160 determines whether or not it is a pixel of the non-interest region image, sends the gradation signal of the non-interest region image to the lower bit adjustment processing unit 162, and adjustment of the image gradation signal of the interest region is unnecessary. The adjusted gray scale signal frame memory 166 is stored as it is as a pixel gray scale signal.
　下位ビット調整処理部１６２では、下位ビットデータメモリ１６４に予め格納された値（例えば、「０」又は「１」）を読み出して、非関心領域画像の階調信号の下位ビット（例えば、１６ビット中の下位８ビット等）に読み出した値を割り当てて、調整済画素階調信号として調整後階調信号フレームメモリ１６６に格納する。なお、本実施の形態では、下位ビットに「０」または「１」を割り当てるものとして説明するが、これに限るものではなく、例えば、１６ビット中の下位８ビットに予め定めた値（「０００１０００１」、「１０００１０００」等の値）を割り当てるようにしてもよい。また、調整対象の下位ビットは、１６ビット中の下位８ビットに限定されるものではない。 The lower bit adjustment processing unit 162 reads out a value (for example, “0” or “1”) stored in advance in the lower bit data memory 164, and lower bits (for example, 16 bits) of the grayscale signal of the non-interest area image. The read out value is assigned to the lower 8 bits in the middle, etc., and the adjusted value is stored in the adjusted gradation signal frame memory 166 as an adjusted pixel gradation signal. In the present embodiment, although it is described that “0” or “1” is assigned to the lower bits, the present invention is not limited to this. For example, a predetermined value (“00010001”) is set to lower 8 bits in 16 bits. And “10001000” may be assigned. Also, the lower bits to be adjusted are not limited to the lower 8 bits of the 16 bits.
　調整後階調信号フレームメモリ１６６は、１フレーム分の階調信号が格納された時点で階調信号送出部１６８を介して静止画像生成部１２８へ階調信号を送出する。 The adjusted gradation signal frame memory 166 transmits the gradation signal to the still image generation unit 128 via the gradation signal transmission unit 168 when the gradation signal for one frame is stored.
　すなわち、非関心領域画像については、下位ビットが固定値に固定されることにより、関心領域よりもＱＬ値の変化度合が小さくなり、動画を表示した時に非関心領域のちらつきが軽減される。 That is, for the non-interest region image, by fixing the lower bits to a fixed value, the change degree of the QL value becomes smaller than that of the interest region, and the flicker of the non-interest region is reduced when displaying the moving image.
　続いて、本実施の形態の作用を図７～図１０のフローチャートに従い説明する。 Subsequently, the operation of the present embodiment will be described according to the flowcharts of FIG. 7 to FIG.
　図７は、放射線画像撮影準備制御ルーチンを示すフローチャートである。 FIG. 7 is a flowchart showing a radiation image capturing preparation control routine.
　ステップ２００では、撮影指示があったか否かが判断され、該判定が否定された場合にはこのルーチンは終了し、肯定された場合にはステップ２０２へ移行する。 In step 200, it is determined whether or not a photographing instruction has been issued. If the determination is negative, the routine ends. If the determination is positive, the process proceeds to step 202.
　ステップ２０２では、初期情報入力画面がディスプレイ８０に表示されてステップ２０４へ移行する。すなわち、予め定められた初期情報入力画面をディスプレイ８０により表示させるようにディスプレイドライバ９２を制御する。 In step 202, an initial information input screen is displayed on the display 80, and the process moves to step 204. That is, the display driver 92 is controlled to cause the display 80 to display a predetermined initial information input screen.
　ステップ２０４では、所定情報が入力されたか否かが判定され、該判定が肯定されるまで待機して、ステップ２０６へ移行する。初期情報入力画面では、例えば、これから放射線画像の撮影を行う被検者の氏名、撮影対象部位、撮影時の姿勢、および撮影時の放射線Ｘの照射条件（本実施の形態では、放射線Ｘを照射する際の管電圧および管電流）の入力を促すメッセージと、これらの情報の入力領域とが表示される。 In step 204, it is determined whether or not predetermined information is input, and the process waits until the determination is affirmed, and then proceeds to step 206. On the initial information input screen, for example, the name of the subject who is about to take a radiation image, the region to be taken, the posture at the time of shooting, and the irradiation condition of the radiation X at the time of shooting (in the present embodiment, radiation X is irradiated And a message prompting the user to input a tube voltage and a tube current), and an input region of such information.
　初期情報入力画面がディスプレイ８０に表示されると、撮影者は、撮影対象とする被検者の氏名、撮影対象部位、撮影時の姿勢、および照射条件を、各々対応する入力領域に操作パネル８２を介して入力する。 When the initial information input screen is displayed on the display 80, the photographer can set the name of the subject to be imaged, the region to be imaged, the posture at the time of imaging, and the irradiation condition to the corresponding input area. Enter through.
　撮影者は、被検者と共に放射線撮影室３２に入室し、例えば、臥位である場合は、対応する臥位台３６の保持部４４に電子カセッテ２０を保持させ、放射線照射源２２Ａを対応する位置に位置決めした後、被検者を所定の撮影位置に位置（ポジショニング）させる。なお、撮影対象部位が腕部、脚部等の電子カセッテ２０を保持部に保持させない状態で放射線画像の撮影を行う場合は、当該撮影対象部位を撮影可能な状態に被検者、電子カセッテ２０、および放射線照射源２２Ａを位置決め（ポジショニング）させる。 The photographer enters the radiation imaging room 32 with the subject and, for example, in the case of a recumbent position, the electronic cassette 20 is held by the holding portion 44 of the corresponding support table 36, and the radiation irradiation source 22A is supported. After positioning at the position, the subject is positioned at a predetermined imaging position (positioning). In the case where a radiographic image is taken in a state in which the holding portion does not hold the electronic cassette 20 such as an arm portion or a leg portion, the subject and the electronic cassette 20 are set in a state where the imaging target portion can be photographed. And the radiation source 22A is positioned.
　その後、撮影者は、放射線撮影室３２を退室し、例えば、初期情報入力画面の下端近傍に表示されている終了ボタンを、操作パネル８２を介して指定する。撮影者によって終了ボタンが指定されると、前記ステップ２０４が肯定されてステップ２０６へ移行する。なお、図７のフローチャートでは、ステップ２０４を無限ループとしたが、操作パネル８２上に設けたキャンセルボタンの操作によって、強制終了させるようにしてもよい。 Thereafter, the photographer leaves the radiation imaging room 32, and designates, for example, an end button displayed near the lower end of the initial information input screen via the operation panel 82. When the photographer designates the end button, step 204 is affirmed and the process moves to step 206. In the flowchart of FIG. 7, step 204 is an infinite loop, but forced termination may be performed by the operation of a cancel button provided on the operation panel 82.
　ステップ２０６では、上記初期情報入力画面において入力された情報（以下、「初期情報」という。）を電子カセッテ２０に無線通信部９６を介して送信した後、次のステップ２０８へ移行して、前記初期情報に含まれる照射条件を放射線発生装置２４へ無線通信部９６を介して送信することにより当該照射条件を設定する。これに応じて放射線発生装置２４の画像処理制御ユニット１０２は、受信した照射条件での照射準備を行う。 In step 206, the information (hereinafter referred to as "initial information") input on the initial information input screen is transmitted to the electronic cassette 20 via the wireless communication unit 96, and then the process proceeds to the next step 208, The irradiation condition is set by transmitting the irradiation condition included in the initial information to the radiation generation apparatus 24 via the wireless communication unit 96. In response to this, the image processing control unit 102 of the radiation generation apparatus 24 prepares for irradiation under the received irradiation conditions.
　次のステップ２１０では、ＡＢＣ制御の起動を指示し、次いで、ステップ２１２へ移行して、放射線の照射開始を指示する指示情報を放射線発生装置２４へ無線通信部９６を介して送信し、このルーチンは終了する。 In the next step 210, the start of ABC control is instructed, and then, the process proceeds to step 212, and instruction information for instructing the start of radiation irradiation is transmitted to the radiation generation apparatus 24 via the wireless communication unit 96, and this routine Ends.
　次に、図８のフローチャートに従い、放射線照射制御の流れを説明する。図８は、放射線照射制御ルーチンを示すフローチャートである。 Next, the flow of radiation irradiation control will be described according to the flowchart of FIG. FIG. 8 is a flowchart showing a radiation irradiation control routine.
　ステップ３００では、照射開始指示があった否かが判断され、否定判定された場合はこのルーチンは終了し、肯定判定された場合はステップ３０２へ移行する。 In step 300, it is determined whether or not an irradiation start instruction has been issued. If a negative determination is made, this routine ends, and if a positive determination is made, the process proceeds to step 302.
　ステップ３０２では、定常時放射線量（初期値）ＸＮが読み出されて、ステップ３０４へ移行する。 In step 302, the steady state radiation dose (initial value) XN is read, and the process proceeds to step 304.
　ステップ３０４では、読み出された定常時放射線量で照射が開始されて、ステップ３０６へ移行する。すなわち、コンソール３０から受信した照射上限に応じた管電圧及び管電流を放射線発生装置２４に印加することにより、放射線照射源２２Ａからの照射を開始する。放射線照射源２２Ａから射出された放射線Ｘは、被検者を透過した後に電子カセッテ２０に到達する。 In step 304, irradiation is started with the read out steady-state radiation dose, and the process proceeds to step 306. That is, by applying the tube voltage and the tube current according to the irradiation upper limit received from the console 30 to the radiation generator 24, the irradiation from the radiation irradiation source 22A is started. The radiation X emitted from the radiation source 22A reaches the electronic cassette 20 after being transmitted through the subject.
　ステップ３０６では、現在格納されている放射線量補正情報が読み出されて、ステップ３０６へ移行する。この放射線量補正情報は、ＡＢＣ制御によって生成されるものであり、補正係数ΔＸとして格納されている。 In step 306, the radiation dose correction information currently stored is read out, and the process proceeds to step 306. The radiation dose correction information is generated by ABC control, and is stored as a correction coefficient ΔX.
　次のステップ３０８では、ＡＢＣ制御に基づく補正処理が実行されて、ステップ３１０へ移行する。すなわち、電子カセッテ２０から得た階調信号（ＱＬ値）に基づいて、関心領域画像のＱＬ値の平均値を演算し、このＱＬ値の平均値が予め定めたしきい値と比較され、しきい値に収束するように、放射線量にフィードバック制御される。 In the next step 308, correction processing based on ABC control is performed, and the process proceeds to step 310. That is, the average value of the QL values of the region of interest image is calculated based on the gradation signal (QL value) obtained from the electronic cassette 20, and the average value of the QL values is compared with a predetermined threshold value, It is feedback controlled to the radiation dose so as to converge to the threshold value.
　ステップ３１０では、撮影終了の指示があったか否かが判断され、該判定が肯定された場合には、ステップ３１２へ移行し、否定された場合にはステップ３０６に戻って上述の処理が繰り返される。 In step 310, it is determined whether or not there is an instruction to end imaging, and if the determination is affirmed, the process proceeds to step 312, and if denied, the process returns to step 306 and the above-described process is repeated.
　そして、ステップ３１２では、照射を終了し、放射線照射制御を終了する。 Then, in step 312, the irradiation is ended, and the radiation irradiation control is ended.
　続いて、図９のフローチャートに従い、画像処理制御の流れを説明する。図９は、画像処理制御ルーチンを示すフローチャートである。 Subsequently, the flow of image processing control will be described according to the flowchart of FIG. FIG. 9 is a flowchart showing an image processing control routine.
　上述のように放射線画像撮影制御が行われると、ステップ４００では、１フレーム分の階調情報が順次取り込まれて、ステップ４０２へ移行する。すなわち、電子カセッテ２０のＴＦＴ基板７４によって生成された階調信号が階調信号取得部１２２に順次取り込まれる。 As described above, when the radiation image capturing control is performed, in step 400, gradation information for one frame is sequentially fetched, and the process proceeds to step 402. That is, the gradation signal generated by the TFT substrate 74 of the electronic cassette 20 is sequentially taken into the gradation signal acquisition unit 122.
　ステップ４０２では、静止画が生成されて、ステップ４０４へ移行する。すなわち、１フレーム分の階調信号を取り込んだところで静止画像生成部１２８によって静止画像を生成する。なお、静止画の生成の際には、後述する階調調整制御によって調整された結果が反映された静止画が生成される。 In step 402, a still image is generated, and the process proceeds to step 404. That is, when the gradation signal of one frame is taken in, the still image generation unit 128 generates a still image. In addition, at the time of generation of a still image, a still image on which a result adjusted by gradation adjustment control described later is reflected is generated.
　ステップ４０４では、動画編集処理が行われて、ステップ４０６へ移行する。動画編集処理は、静止画像生成部１２８によって生成された１フレーム毎の静止画像を組み合わせて動画編集が動画編集部１３０によって行われる。 In step 404, a moving image editing process is performed, and the process moves to step 406. In the moving image editing process, moving image editing is performed by the moving image editing unit 130 by combining the still images of each frame generated by the still image generating unit 128.
　ステップ４０６では、画像表示処理が行われて、ステップ４０８へ移行する。画像表示処理は、動画編集処理によって生成された動画像をディスプレイドライバ９２へ送出することにより、ディスプレイドライバ９２によってディスプレイ８０への表示が行われる。 In step 406, image display processing is performed, and the process moves to step 408. In the image display process, display on the display 80 is performed by the display driver 92 by transmitting a moving image generated by the moving image editing process to the display driver 92.
　ステップ４０８では、関心領域設定が行われて、ステップ４１０へ移行する。関心領域の設定は、例えば、パターンマッチングや、移動量が大きい領域の検出などを行うことにより、関心領域を設定するが、ユーザの操作によって関心領域の設定を行うようにしてもよい。 In step 408, a region of interest setting is performed, and the process moves to step 410. The setting of the region of interest is performed by, for example, pattern matching, detection of a region having a large amount of movement, or the like to set the region of interest, but the setting of the region of interest may be performed by the user's operation.
　ステップ４１０では、設定された関心領域の階調信号が関心領域抽出部１４０によって抽出されて、ステップ４１２へ移行する。 In step 410, the tone signal of the set region of interest is extracted by the region of interest extraction unit 140, and the process proceeds to step 412.
　ステップ４１２では、関心領域の階調信号の平均ＱＬ値が平均ＱＬ値演算部１３２によって演算されて、ステップ４１４へ移行し、基準ＱＬ値メモリ１３６に格納された基準ＱＬ値が読み出されて、ステップ４１６へ移行する。 In step 412, the average QL value of the grayscale signal of the region of interest is calculated by the average QL value calculator 132, and the process proceeds to step 414 where the reference QL value stored in the reference QL value memory 136 is read. Proceed to step 416.
　ステップ４１６では、演算された平均ＱＬ値と、読み出された基準ＱＬ値とがＡＢＣ制御部１３４によって比較されて、補正の可否が判定されて、ステップ４１８へ移行する。例えば、補正の可否の判定は、比較の結果において、差が所定以上のであれば予め定めた量の補正を行い、差が所定未満であれば補正しないといった所謂オン／オフ判定であってもよいし、差に基づいて、予め定めた演算式（例えば、ＰＩＤ制御等に基づく演算式）により演算された解であってもよい。 In step 416, the calculated average QL value and the read reference QL value are compared by the ABC control unit 134 to determine whether or not correction is possible, and the process proceeds to step 418. For example, the determination as to whether the correction is possible may be a so-called on / off determination that a predetermined amount of correction is performed if the difference is greater than or equal to a predetermined result in the comparison result, and no correction is performed if the difference is less than the predetermined Alternatively, it may be a solution calculated by a predetermined arithmetic expression (for example, an arithmetic expression based on PID control or the like) based on the difference.
　ステップ４１８では、ステップ４１６の比較・補正可否判定結果に基づいて、放射線量の補正情報ΔＸがＡＢＣ制御部１３４によって生成されて、ステップ４２０へ移行する。 In step 418, the correction information ΔX of the radiation amount is generated by the ABC control unit 134 based on the comparison / correction determination result in step 416, and the process proceeds to step 420.
　そして、ステップ４２０では、生成した補正情報ΔＸが放射線量調整部１２０に送出されることにより格納されて、画像処理制御を終了する。 Then, in step 420, the generated correction information ΔX is stored by being sent to the radiation dose adjustment unit 120, and the image processing control is ended.
　次に、図１０のフローチャートに従い、階調調整制御の流れを説明する。図１０は、階調調整部の階調調整制御ルーチンを示すフローチャートである。 Next, the flow of gradation adjustment control will be described according to the flowchart of FIG. FIG. 10 is a flowchart showing a tone adjustment control routine of the tone adjustment unit.
　ステップ５００では、階調信号受付部１５０により、階調信号取得部１２２によって取得された調整前の階調信号を受け付けて、ステップ５０２へ移行する。 In step 500, the gradation signal reception unit 150 receives the gradation signal before adjustment acquired by the gradation signal acquisition unit 122, and the process proceeds to step 502.
　ステップ５０２では、調整前の階調信号が調整前階調信号フレームメモリ１５２に１フレーム単位で一時格納されて、ステップ５０４へ移行する。 In step 502, the gradation signal before adjustment is temporarily stored in the pre-adjustment gradation signal frame memory 152 in units of one frame, and the process proceeds to step 504.
　ステップ５０４では、非関心領域抽出部１２６によって抽出された非関心領域画像の階調信号が非関心領域画像階調信号メモリ１５６に一時格納されて、ステップ５０６へ移行する。 In step 504, the tone signal of the non-interest region image extracted by the non-interest region extraction unit 126 is temporarily stored in the non-interest region image tone signal memory 156, and the process proceeds to step 506.
　ステップ５０６では、座標（ｘ、ｙ）抽出部１５４により、調整前の階調信号から予め定めた走査方向順に、座標（ｘ、ｙ）の画素が抽出されて、ステップ５０８へ移行する。 In step 506, the coordinate (x, y) extraction unit 154 extracts pixels of the coordinate (x, y) in order of a predetermined scanning direction from the gradation signal before adjustment, and the process proceeds to step 508.
　ステップ５０８では、抽出された画素が調整対象の画素か否か照合部１６０によって判定される。該判定は、非関心領域抽出部１２６によって抽出された非関心領域の画素（座標（ｘ、ｙ）抽出部１５８によって抽出された画素）であるか否かを判定し、該判定が肯定された場合にはステップ５１０へ移行し、否定された場合にはステップ５１４へ移行する。 In step S <b> 508, the matching unit 160 determines whether the extracted pixel is a pixel to be adjusted. This determination determines whether or not the pixel of the non-interest region extracted by the non-interest region extraction unit 126 (the pixel extracted by the coordinate (x, y) extraction unit 158), and the determination is affirmed In the case, the process proceeds to step 510, and if not, the process proceeds to step 514.
　ステップ５１０では、非関心領域の下位ビットデータが下位ビット調整処理部１６２によって読み出されて、ステップ５１２へ移行する。 At step 510, the lower bit data of the non-interest region is read by the lower bit adjustment processing unit 162, and the process proceeds to step 512.
　ステップ５１２では、下位ビット調整処理部１６２によって階調信号の下位ビットが調整されて、ステップ５１４へ移行する。本実施の形態では、下位ビットデータメモリ１６４に格納された予め定めた値に調整する。例えば、１６ビット中の下位８ビットを「00000000」又は「11111111」に調整する。 At step 512, the lower bit adjustment processing unit 162 adjusts the lower bits of the gradation signal, and the process proceeds to step 514. In the present embodiment, adjustment is made to a predetermined value stored in the lower bit data memory 164. For example, the lower 8 bits in 16 bits are adjusted to "00000000" or "11111111".
　ステップ５１４では、調整後の階調信号が１フレーム単位で調整後階調信号フレームメモリ１６６に一時格納されて、ステップ５１６へ移行する。 At step 514, the adjusted gradation signal is temporarily stored in the adjusted gradation signal frame memory 166 in units of one frame, and the process proceeds to step 516.
　ステップ５１６では、調整後階調信号フレームメモリ１６６に１フレーム分の階調信号が格納されたか否か判定され、該判定が否定された場合にはステップ５０６へ戻って１フレーム分の階調信号が格納されて、判定が肯定されるまで上述の処理が繰り返され、判定が肯定されたところでステップ５１８へ移行する。 At step 516, it is judged whether or not the gradation signal for one frame is stored in the adjusted gradation signal frame memory 166, and if the judgment is negative, the process returns to step 506 and the gradation signal for one frame Is stored, and the above process is repeated until the determination is affirmed, and when the determination is affirmed, the process proceeds to step 518.
　ステップ５１８では、調整後の階調信号が静止画像生成部１２８へ送出されて、階調調整制御を終了する。 In step 518, the adjusted gradation signal is sent to the still image generation unit 128, and the gradation adjustment control is ended.
　すなわち、階調調整制御によって非関心領域の階調信号（ＱＬ値）の下位ビットを予め定めた値に調整することによって、関心領域の階調信号よりも非関心領域の階調の変化度合を小さくすることができる。これによって、動画を生成した時には、非関心領域の階調変化が関心領域よりも小さくなるので、動画撮影する場合のＡＢＣ制御によるちらつきを抑制して目の疲れを軽減することができる。 That is, by adjusting the lower bits of the gradation signal (QL value) of the non-interest region to a predetermined value by gradation adjustment control, the change degree of the gradation of the non-interest region is higher than the gradation signal of the interest region. It can be made smaller. Thus, when a moving image is generated, the gradation change of the non-interest region is smaller than that of the region of interest, so it is possible to suppress flicker due to ABC control when shooting a moving image and reduce eye fatigue.
　続いて、変形例について説明する。上記の実施の形態では、ステップ５１０で非関心領域の下位ビットを読み出し、ステップ５１２で非関心領域の下位ビットを予め定めた値に調整することにより、関心領域よりも非関心領域のＱＬ値の変化度合が小さくなるように調整した。変形例では、非関心領域のＱＬ値の変化度合を関心領域よりも小さくする別の方法を適用した例を説明する。 Subsequently, modified examples will be described. In the above embodiment, the lower bits of the non-interest region are read in step 510, and the lower bits of the non-interest region are adjusted to a predetermined value in step 512, whereby the QL value of the non-interest region is Adjustment was made to reduce the degree of change. In the modified example, an example will be described in which another method of making the degree of change of the QL value of the non-interest region smaller than the interest region is applied.
　変形例では、Ｎフレームの非関心領域については、（Ｎ－１）フレームのＱＬ値の変動値を適用して、関心領域以外の領域についてはＱＬ値の変動を遅延させるようにしたものである。すなわち、図６において、下位ビットデータメモリ１６４の代わりに１フレーム前階調メモリを設け、下位ビット調整処理部１６２の代わりに１フレーム前階調信号置き換え処理を設ける。そして、１フレーム前の階調信号を格納しておいて、非関心領域の画素については１フレーム前の階調信号に置き換えるようにしたものである。 In the modification, the variation value of the QL value of the (N-1) frame is applied to the non-interest region of the N frame, and the variation of the QL value is delayed for the region other than the region of interest. . That is, in FIG. 6, the previous tone memory of one frame is provided instead of the lower bit data memory 164, and the previous tone signal replacement process of one frame is provided instead of the lower bit adjustment processing unit 162. Then, the gradation signal of one frame before is stored, and the pixels of the non-interest region are replaced with the gradation signal of one frame before.
　図１１は、変形例の階調調整部の階調調整制御ルーチンを示すフローチャートである。なお、上記の実施の形態と同一処理については同一符号を付して説明する。 FIG. 11 is a flowchart showing the tone adjustment control routine of the tone adjustment unit of the modification. The same processes as those in the above embodiment will be described with the same reference numerals.
　ステップ５００では、階調信号受付部１５０により、階調信号取得部１２２によって取得された調整前の階調信号を受け付けて、ステップ５０２へ移行する。 In step 500, the gradation signal reception unit 150 receives the gradation signal before adjustment acquired by the gradation signal acquisition unit 122, and the process proceeds to step 502.
　ステップ５０２では、調整前の階調信号が調整前階調信号フレームメモリ１５２に１フレーム単位で一時格納されて、ステップ５０４へ移行する。 In step 502, the gradation signal before adjustment is temporarily stored in the pre-adjustment gradation signal frame memory 152 in units of one frame, and the process proceeds to step 504.
　ステップ５０４では、非関心領域抽出部１２６によって抽出された非関心領域画像の階調信号が非関心領域画像階調信号メモリ１５６に一時格納されて、ステップ５０６へ移行する。 In step 504, the tone signal of the non-interest region image extracted by the non-interest region extraction unit 126 is temporarily stored in the non-interest region image tone signal memory 156, and the process proceeds to step 506.
　ステップ５０６では、座標（ｘ、ｙ）抽出部１５４により、調整前の階調信号から予め定めた走査方向順に、座標（ｘ、ｙ）の画素が抽出されて、ステップ５０８へ移行する。 In step 506, the coordinate (x, y) extraction unit 154 extracts pixels of the coordinate (x, y) in order of a predetermined scanning direction from the gradation signal before adjustment, and the process proceeds to step 508.
　ステップ５０８では、抽出された画素が調整対象の画素か否か照合部１６０によって判定される。該判定は、非関心領域抽出部１２６によって抽出された非関心領域の画素（座標（ｘ、ｙ）抽出部１５８によって抽出された画素）であるか否かを判定し、該判定が肯定された場合にはステップ５１１へ移行し、否定された場合にはステップ５１４へ移行する。 In step S <b> 508, the matching unit 160 determines whether the extracted pixel is a pixel to be adjusted. This determination determines whether or not the pixel of the non-interest region extracted by the non-interest region extraction unit 126 (the pixel extracted by the coordinate (x, y) extraction unit 158), and the determination is affirmed In the case, the process proceeds to step 511, and in the case of being denied, the process proceeds to step 514.
　ステップ５１１では、１フレーム前の階調信号が読み出されて、ステップ５１３へ移行する。 In step 511, the gradation signal of one frame before is read, and the process proceeds to step 513.
　ステップ５１３では、階調信号が１フレーム前の階調信号に置き換える調整が行われて、ステップ５１４へ移行する。 At step 513, adjustment is performed to replace the tone signal with the tone signal one frame before, and the process moves to step 514.
　ステップ５１４では、調整後の階調信号が１フレーム単位で調整後階調信号フレームメモリ１６６に一時格納されて、ステップ５１６へ移行する。 At step 514, the adjusted gradation signal is temporarily stored in the adjusted gradation signal frame memory 166 in units of one frame, and the process proceeds to step 516.
　ステップ５１６では、調整後階調信号フレームメモリ１６６に１フレーム分の階調信号が格納されたか否か判定され、該判定が否定された場合にはステップ５０６へ戻って１フレーム分の階調信号が格納されて、判定が肯定されるまで上述の処理が繰り返され、判定が肯定されたところでステップ５１８へ移行する。 At step 516, it is judged whether or not the gradation signal for one frame is stored in the adjusted gradation signal frame memory 166, and if the judgment is negative, the process returns to step 506 and the gradation signal for one frame Is stored, and the above process is repeated until the determination is affirmed, and when the determination is affirmed, the process proceeds to step 518.
　ステップ５１８では、調整後の階調信号が静止画像生成部１２８へ送出されて、階調調整制御を終了する。 In step 518, the adjusted gradation signal is sent to the still image generation unit 128, and the gradation adjustment control is ended.
　すなわち、変形例では、階調信号調整部１２４が、Ｎフレームの非関心領域については、（Ｎ－１）フレームのＱＬ値の変動値を適用して、関心領域以外の領域についてＱＬ値の変動を遅延させるように階調信号を調整している。これにより、関心領域よりも非関心領域のＱＬ値の変動時定数を遅くして緩やかに変動させることができるので、画像のちらつきを抑制することができる。 That is, in the modification, the gradation signal adjustment unit 124 applies the variation value of the QL value of the (N-1) frame to the non-interest region of the N frame to change the QL value for the region other than the region of interest. The tone signal is adjusted so as to delay. As a result, the fluctuation time constant of the QL value of the non-interest region can be made slower and more gently than the region of interest, so that flickering of the image can be suppressed.
　なお、変形例では、階調信号調整部１２４が、非関心領域については１フレーム前の階調信号を適用して変動時定数を遅くするように非関心領域の階調信号を調整したが、階調信号調整部１２４は、数フレーム続けて（Ｎ－１）フレームを適用して変動時定数を更に遅くするように非関心領域の階調信号を調整するようにしてもよい。また、階調信号調整部１２４は、非関心領域の下位ビットを関心領域の制御周期よりも低い周期で変動するように調整するようにしてもよい。例えば、関心領域のフレームレートに対して非関心領域のフレームレートを低くするようにしてもよい。 In the modification, although the gradation signal adjustment unit 124 adjusts the gradation signal of the non-interest region so as to delay the fluctuation time constant by applying the gradation signal of the previous frame to the non-interest region, The gradation signal adjustment unit 124 may adjust the gradation signal of the non-interest region so as to further delay the fluctuation time constant by applying (N−1) frames for several consecutive frames. In addition, the gradation signal adjustment unit 124 may adjust the lower bits of the non-interest region to fluctuate at a cycle lower than the control period of the interest region. For example, the frame rate of the non-interest region may be lowered relative to the frame rate of the region of interest.
　また、非関心領域のＱＬ値の変化度合を関心領域よりも小さくする上記以外の方法としては、階調信号調整部１２４が、ＡＢＣ制御が終了するまで（Ｎ－１）フレームのＱＬ値の変動値を適用して非関心領域のＱＬ値を一定に保持するようにしてもよい。 Further, as another method for making the change degree of the QL value of the non-interest region smaller than the interest region, the gradation signal adjustment unit 124 changes the QL value of the (N-1) frame until the ABC control ends. A value may be applied to keep the QL value of the non-interest region constant.
　また、上記の実施の形態及び変形例における各フローチャートで示した処理は、プログラムとして各種記憶媒体に記憶して流通するようにしてもよい。 Further, the processes shown in the flowcharts in the above-described embodiment and modification may be stored as a program in various storage media and distributed.
　また、上記の実施の形態では、本発明の放射線としてＸ線を適用した場合について説明したが、本発明はこれに限定されるものではなく、例えば、α線、γ線等の他の放射線が含まれる。 In the above embodiment, the X-ray is applied as the radiation of the present invention, but the present invention is not limited to this, and other radiation such as α-ray and γ-ray may be used. included.
　尚、日本出願特願２０１１－２０７５６８号の開示はその全体が参照により本明細書に取り込まれる。明細書に記載された全ての文献、特許出願、および技術規格は、個々の文献、特許出願、および技術規格が参照により取り込まれることが具体的かつ個々に記された場合と同程度に、本明細書中に参照により取り込まれる。 The disclosure of Japanese Patent Application No. 2011-207568 is incorporated herein by reference in its entirety. All documents, patent applications and technical standards mentioned in the specification are as accurate as if each individual document, patent application and technical standard were specifically and individually indicated to be incorporated by reference. It is incorporated by reference in the specification.
　　　　１０　　放射線情報システム
　　　　１６　　撮影システム
　　　　２０　　電子カセッテ
　　　　２２　　放射線照射制御ユニット
　　　　２２Ａ　　放射線照射源
　　　　２４　　放射線発生装置
　　　　２６　　放射線検出器
　　　　３０　　コンソール
　　　　７４　　ＴＦＴ基板
　　　　１０２　　画像処理制御ユニット
　　　　１０４　　システム制御部
　　　　１０６　　パネル制御部
　　　　１０８　　画像処理制御部
　　　　１２０　　放射線量調整部
　　　　１２２　　階調信号取得部
　　　　１２４　　階調信号調整部
　　　　１２６　　非関心領域抽出部
　　　　１２８　　静止画像生成部
　　　　１３０　　動画編集部
　　　　１３２　　平均ＱＬ値演算部
　　　　１３４　　ＡＢＣ制御部
　　　　１３６　　基準ＱＬ値メモリ
　　　　１６２　　下位ビット調整部
　　　　１６４　　下位ビットデータメモリ DESCRIPTION OF SYMBOLS 10 radiation information system 16 imaging system 20 electronic cassette 22 radiation irradiation control unit 22A radiation irradiation source 24 radiation generation device 26 radiation detector 30 console 74 TFT substrate 102 image processing control unit 104 system control part 106 panel control part 108 image processing control part 120 radiation dose adjustment unit 122 gradation signal acquisition unit 124 gradation signal adjustment unit 126 non-interest region extraction unit 128 still image generation unit 130 moving image editing unit 132 average QL value calculation unit 134 ABC control unit 136 reference QL value memory 162 low order bit Adjustment unit 164 lower bit data memory

Claims (17)

  1. 　設定された設定値に応じた放射線照射エネルギーで放射線を照射する放射線照射部から照射されて被検体を通過した放射線量を、複数の画素を備えた放射線検出器で受け、当該画素毎に受ける放射線量に応じたデジタルの階調信号を出力する放射線画像撮影部から出力される前記階調信号に基づいて、１フレームの静止画像情報を生成し、且つ、前記静止画像情報を連続的に複数フレーム組み合わせて動画像情報を生成する画像情報生成部と、
    　前記画像情報生成部で生成された前記動画像情報が示す画像の一部を関心領域として設定する関心領域設定部と、
    　前記階調信号に基づいて、少なくとも１フレームの前記静止画像情報の一部における前記階調信号の演算値が予め定めた範囲の値になるように、前記放射線照射部から照射される前記放射線エネルギーの設定値を所定の制御周期でフィードバック制御する制御部と、
    　前記制御部の前記フィードバック制御による前記階調信号の変化度合が、前記関心領域設定部によって設定された前記関心領域よりも前記関心領域以外の非関心領域の方が小さくなるように、前記非関心領域に対応する前記階調信号を調整する調整部と、
    　を備えた放射線動画処理装置。     A radiation detector including a plurality of pixels receives a radiation dose that has been irradiated from a radiation irradiation unit that irradiates radiation with radiation energy corresponding to the set value set, and the radiation received for each of the pixels Still image information of one frame is generated based on the gradation signal output from the radiation image capturing unit that outputs a digital gradation signal according to the amount, and the still image information is continuously divided into a plurality of frames An image information generation unit that generates moving image information in combination;
    A region of interest setting unit configured to set, as a region of interest, a part of the image represented by the moving image information generated by the image information generation unit;
    The radiation energy irradiated from the radiation irradiator such that the calculated value of the gradation signal in a part of the still image information of at least one frame becomes a value in a predetermined range based on the gradation signal A control unit that performs feedback control of the set value of at a predetermined control cycle;
    The non-interest region such that the change degree of the gradation signal by the feedback control of the control unit is smaller in the non-interest regions other than the interest region than the interest region set by the region-of-interest setting unit. An adjusting unit that adjusts the gradation signal corresponding to the area;
    Radiation video processing equipment with.
  2. 　前記階調信号の演算値が、前記関心領域の階調信号の平均値または重み付けを含む加算に基づく値である
    　請求項１に記載の放射線動画処理装置。     The radiation moving image processing apparatus according to claim 1, wherein the operation value of the gradation signal is a value based on addition including an average value or weighting of the gradation signal of the region of interest.
  3. 　前記階調信号が、Ｎ（Ｎは２以上の自然数）ビットのデジタル信号であり、前記調整部が、前記Ｎビットの下位のｎ（ｎ＜Ｎの自然数）ビットの信号を予め定めた値に調整する
    　請求項１又は請求項２に記載の放射線動画処理装置。     The gradation signal is a digital signal of N (N is a natural number of 2 or more) bits, and the adjustment unit sets the lower n (n <N natural number) bit signal of the N bits to a predetermined value. The radiation moving image processing apparatus according to claim 1, wherein the adjustment is performed.
  4. 　前記調整部は、前記予め定めた値として、「０」または「１」に調整する
    　請求項３に記載の放射線動画撮影装置。     The radiation moving image imaging apparatus according to claim 3, wherein the adjustment unit adjusts the value to "0" or "1" as the predetermined value.
  5. 　前記調整部は、前記非関心画像の画素として取得する前記階調信号として（Ｎ－１）フレームの階調信号を適用して、前記関心領域よりも前記非関心領域の時定数が遅くなるように調整する
    　請求項１又は請求項２に記載の放射線動画処理装置。     The adjustment unit applies a gradation signal of (N-1) frame as the gradation signal acquired as a pixel of the non-interest image so that a time constant of the non-interest region is later than that of the interest region. The radiation moving image processing apparatus according to claim 1 or 2.
  6. 　前記調整部は、前記非関心領域の画素として取得する前記階調信号を、前記制御部による制御が終了するまで一定に保持するように調整する
    　請求項１又は請求項２に記載の放射線動画処理装置。     The radiation moving image processing according to claim 1 or 2, wherein the adjustment unit adjusts the gradation signal acquired as a pixel of the non-interest region so as to be held constant until the control by the control unit ends. apparatus.
  7. 　前記調整部は、前記関心領域の階調信号の変化周期よりも前記非関心領域の階調信号の変化周期が遅くなるように前記階調信号を調整する
    　請求項１又は請求項２に記載の放射線動画処理装置。     The said adjustment part adjusts the said gradation signal so that the change period of the gradation signal of the said non-interest region may become late rather than the change period of the gradation signal of the said region of interest. Radiation video processing equipment.
  8. 　設定された設定値に応じた放射線照射エネルギーで放射線を照射する放射線照射部から照射されて被検体を通過した放射線量を、複数の画素を備えた放射線検出器で受け、当該画素毎に受ける放射線量に応じたデジタルの階調信号を出力する放射線画像撮影部と、
    　請求項１～７の何れか１項に記載の放射線動画処理装置と、
    　を備えた放射線動画撮影装置。     A radiation detector including a plurality of pixels receives a radiation dose that has been irradiated from a radiation irradiation unit that irradiates radiation with radiation energy corresponding to the set value set, and the radiation received for each of the pixels A radiation imaging unit that outputs digital gradation signals according to the amount;
    A radiation moving image processing apparatus according to any one of claims 1 to 7;
    Radiation video camera equipped with
  9. 　設定された設定値に応じた放射線照射エネルギーで放射線を照射する放射線照射部と、
    　請求項８に記載の放射線動画撮影装置と、
    　を備えた放射線動画撮影システム。     A radiation irradiating unit that irradiates radiation with radiation energy according to the set value set;
    A radiation moving image photographing apparatus according to claim 8;
    Radiography system equipped with
  10. 　設定された設定値に応じた放射線エネルギーで被検体に向けて放射線照射部から放射線を照射し、被検体を通過した放射線量を、複数の画素を備えた放射線検出器で受け、
    　当該画素毎に受ける放射線量に応じたデジタルの階調信号に基づいて、１フレームの静止画像情報を生成し、且つ、前記静止画像情報を連続的に複数フレーム組み合わせて動画像情報を生成して、生成した前記動画像情報が示す画像の一部を関心領域として設定し、
    　前記階調信号に基づいて、少なくとも１フレームの前記静止画像情報の一部における前記階調信号の演算値が予め定めた範囲の値になるように、前記放射線エネルギーの設定値を所定の制御周期でフィードバック制御する制御部の前記フィードバック制御による前記階調信号の変化度合が、設定された前記関心領域よりも前記関心領域以外の非関心領域の方が小さくなるように、前記非関心領域に対応する前記階調信号を調整する
    　放射線動画撮影方法。     The radiation irradiating unit irradiates radiation from the radiation irradiating unit with radiation energy according to the set value set, and receives a radiation dose that has passed through the object with a radiation detector including a plurality of pixels,
    Still image information of one frame is generated based on a digital gradation signal according to the radiation amount received for each pixel, and moving image information is generated by combining a plurality of frames of the still image information continuously. Setting a part of the image indicated by the generated moving image information as a region of interest;
    The set value of the radiation energy is set to a predetermined control period so that the calculated value of the gradation signal in a part of the still image information of at least one frame becomes a value in a predetermined range based on the gradation signal. Corresponds to the non-interest region such that the change degree of the gradation signal by the feedback control of the control unit that performs feedback control is smaller in the non-interest region other than the interest region than the set region of interest A radiation moving image photographing method for adjusting the gradation signal.
  11. 　前記階調信号の演算値が、前記関心領域の階調信号の平均値または重み付けを含む加算に基づく値である
    　請求項１０に記載の放射線動画撮影方法。     The radiation moving image photographing method according to claim 10, wherein the operation value of the gradation signal is a value based on addition including an average value or weighting of the gradation signal of the region of interest.
  12. 　前記階調信号が、Ｎ（Ｎは２以上の自然数）ビットのデジタル信号であり、前記非関心領域の画素として取得する前記階調信号の前記Ｎビットの下位のｎ（ｎ＜Ｎの自然数）ビットの信号を予め定めた値に調整する
    　請求項１０又は請求項１１に記載の放射線動画撮影方法。     The gradation signal is a digital signal of N (N is a natural number of 2 or more) bits, and the lower n of the N bits of the gradation signal acquired as a pixel of the non-interest region (natural number of n <N) The radiation moving image photographing method according to claim 10, wherein the bit signal is adjusted to a predetermined value.
  13. 　前記予め定めた値として、「０」または「１」に調整する
    　請求項１２に記載の放射線動画撮影方法。     The method according to claim 12, wherein the predetermined value is adjusted to "0" or "1".
  14. 　前記非関心画像の画素として取得する前記階調信号として（Ｎ－１）フレームの階調信号を適用して、前記関心領域よりも前記非関心領域の時定数が遅くなるように調整する
    　請求項１０又は請求項１１に記載の放射線動画撮影方法。     The gradation signal of the (N-1) frame is applied as the gradation signal acquired as a pixel of the non-interest image, and the time constant of the non-interest region is adjusted to be later than the interest region. The radiation moving image imaging method according to claim 10 or claim 11.
  15. 　前記非関心領域の画素として取得する前記階調信号を、前記フィードバック制御が終了するまで一定に保持するように調整する
    　請求項１０又は請求項１１に記載の放射線動画撮影方法。     The radiation moving image photographing method according to claim 10, wherein the gradation signal acquired as a pixel of the non-interest region is adjusted so as to be kept constant until the feedback control is completed.
  16. 　前記関心領域の階調信号の変化周期よりも前記非関心領域の階調信号の変化周期が遅くなるように前記階調信号を調整する
    　請求項１０又は請求項１１に記載の放射線動画撮影方法。     The radiation moving image photographing method according to claim 10, wherein the gradation signal is adjusted such that a change period of the gradation signal of the non-interest region is later than a change period of the gradation signal of the region of interest.
  17. 　コンピュータを請求項１～７の何れか１項に記載の放射線動画処理装置を構成する各部として機能させるための放射線動画撮影プログラム。 A radiation moving image photographing program for causing a computer to function as each unit constituting the radiation moving image processing apparatus according to any one of claims 1 to 7.
PCT/JP2012/065617 2011-09-22 2012-06-19 Fluoroscopic processing device, fluoroscopy device, fluoroscopy system, fluoroscopy method, and fluoroscopy program WO2013042410A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2011207568 2011-09-22
JP2011-207568 2011-09-22

Publications (1)

Publication Number Publication Date
WO2013042410A1 true WO2013042410A1 (en) 2013-03-28

Family

ID=47914191

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2012/065617 WO2013042410A1 (en) 2011-09-22 2012-06-19 Fluoroscopic processing device, fluoroscopy device, fluoroscopy system, fluoroscopy method, and fluoroscopy program

Country Status (1)

Country Link
WO (1) WO2013042410A1 (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006105861A (en) * 2004-10-07 2006-04-20 Toshiba It & Control Systems Corp X-ray inspection apparatus and tube voltage/tube current regulation method therefor
JP2007029161A (en) * 2005-07-22 2007-02-08 Toshiba Corp X-ray apparatus
JP2011005050A (en) * 2009-06-26 2011-01-13 Canon Inc Image processing method and image processing apparatus

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006105861A (en) * 2004-10-07 2006-04-20 Toshiba It & Control Systems Corp X-ray inspection apparatus and tube voltage/tube current regulation method therefor
JP2007029161A (en) * 2005-07-22 2007-02-08 Toshiba Corp X-ray apparatus
JP2011005050A (en) * 2009-06-26 2011-01-13 Canon Inc Image processing method and image processing apparatus

Similar Documents

Publication Publication Date Title
JP5738510B2 (en) Image acquisition and processing chain for dual energy radiation imaging using a portable flat panel detector
JP5840588B2 (en) Radiation image capturing apparatus, correction data acquisition method and program
JP5998615B2 (en) Radiation imaging system
JP5643131B2 (en) Radiation imaging system
JP5797630B2 (en) Radiation image capturing apparatus, pixel value acquisition method, and program
JP5042887B2 (en) Radiation imaging equipment
US20130077746A1 (en) Device and method for assisting in initial setting of imaging condition, and radiation imaging apparatus
WO2013125113A1 (en) Radiographic imaging control device, radiographic imaging system, control method for radiographic imaging device, and control program for radiographic imaging
JP6225690B2 (en) Tomographic image generation system
WO2013042416A1 (en) Radiographic moving image processing device, radiographic moving image shooting device, radiographic moving image shooting system, radiographic moving image shooting method, radiographic moving image shooting program, and memory medium for radiographic moving image shooting program
WO2013042514A1 (en) Fluoroscopy device, method for setting region of interest for fluoroscopy device, radiography system, and fluoroscopy control program
JP2006026283A (en) Radiography system
WO2013042410A1 (en) Fluoroscopic processing device, fluoroscopy device, fluoroscopy system, fluoroscopy method, and fluoroscopy program
JP2012075798A (en) Radiographic imaging apparatus and radiographic imaging system, image processing device, and program
JP2005296277A (en) X-ray diagnostic apparatus and diagnostic method using the same
WO2013042413A1 (en) Radiographic moving image processing device, radiographic moving image shooting device, radiographic moving image shooting system, radiographic moving image shooting method, and radiographic moving image shooting program
JP2004188094A (en) Radiographic apparatus and radiographic system
JP2013056031A (en) Device and method for aid with decision on photographing condition
JP2007330275A (en) Radiography system
JP4754812B2 (en) X-ray equipment
WO2013042415A1 (en) Radiographic moving image shooting device, method for setting region-of-interest for radiographic moving image shooting device, radioactive moving image shooting system, radiographic moving image shooting control program, and memory medium for radiographic moving image shooting control program
JP2004337197A (en) X-ray imaging device
KR101708116B1 (en) The apparatus and method for x-ray imaging using portable x-ray device
JP2013180050A (en) Radiographic imaging control device, radiation image photographing system, control method for radiographic apparatus and control program for radiation image photographing
JP2013066558A (en) Fluoroscopic processing device, fluoroscopy device, fluoroscopy system, fluoroscopy method, and fluoroscopy program

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12833994

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12833994

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP