JP2009240468A - Radiographic imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a photographer to confirm an imaging range easily without imposing a burden on a subject in a radiographic imaging apparatus prepared for long-length imaging of a range larger than a detecting range of a radiographic image detection means. <P>SOLUTION: In the radiographic imaging apparatus 3, a plurality of regions partitioned in a moving direction (in Fig.1, the vertical direction) of a radiographic imaging part are displayed on a surface facing the subject on a screen 16 disposed between the radiographic imaging part 15 and the subject. When the region which is the imaging range is entered out of the plurality of regions, moving ranges of a radiation emitting part 12 and the radiographic imaging part 15 in long-length imaging are determined from the entered imaging region. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a radiographic image capturing apparatus that supports long imaging in a range wider than the detection range of a radiographic image detecting means.

  2. Description of the Related Art Conventionally, in the medical field and the like, various types of radiation detectors that record a radiation image related to a subject by irradiation with radiation that has passed through the subject have been proposed and put into practical use.

  As the radiation detector, for example, as described in Patent Document 1, there is a radiation detector using a semiconductor such as amorphous selenium that generates a charge by irradiation of radiation, and as such a radiation detector, a so-called radiation detector is used. An optical reading type and a TFT reading type have been proposed.

  If such a radiation detector is used, image information obtained by imaging can be acquired as digital data, so that affinity with a diagnosis support apparatus using a computer can be increased.

  For example, as described in Patent Literature 2-4, in order to perform long imaging in a range wider than the detection range of the radiation image detection means, the radiation detector is moved in parallel along the radiation detection surface. It has been proposed to shoot a plurality of times at different locations and then combine the obtained images to generate an image in a wider range than the detection range of the radiation detector.

Furthermore, in such an apparatus for taking an image by moving the radiation detector, in order to prevent the subject from coming into contact with the radiation detector, it is also proposed to arrange a screen between the radiation detector and the subject. Has been made.
JP 2000-105297 A JP 2005-270277 A JP 2006-500126 A JP 2004-358254 A Noto 3118190

  In the long shooting as described above, the shooting range can be freely changed according to the contents of the examination, such as the whole subject, only the upper body, only the lower body, etc. It is necessary to set the imaging range, that is, the range of movement of the radiation detector for each subject with the subject standing in front of the radiographic imaging device.

  Until now, when setting the movement range of the radiation detector, a lamp that irradiates the radiation irradiation field of view to the subject by darkening the radiographic imaging room after standing the subject in front of the radiographic imaging device Or, a laser marker or the like was irradiated, and the photographer determined the photographing range for the subject by using the light of the lamp or the laser marker.

  However, with such a method, the subject is exposed to a lamp or laser marker in a relatively dark environment, which may cause a burden on the subject, such as feeling dazzling, and sets the range of movement of the radiation detector In order to do so, there is a problem that it takes time to start photographing because the above procedure must be taken.

  Therefore, there is a demand for an apparatus that does not place a burden on the subject and that allows the photographer to easily check the shooting range.

  The present invention has been made in view of the above circumstances, and does not place a burden on a subject in a radiographic image capturing apparatus that supports long imaging in a range wider than the detection range of the radiographic image detection means. An object of the present invention is to provide a radiographic image capturing apparatus capable of easily confirming an imaging range.

  The radiographic image capturing apparatus of the present invention includes a radiographic image detection unit that captures a radiographic image of a subject by receiving radiation that has passed through the subject, and a radiographic image detection unit that are parallel to the radiation detection surface of the radiographic image detection unit. An image generating means for combining a plurality of radiographic images taken at different positions of the radiographic image detecting means and generating a wider range than the detection range of the radiographic image detecting means; A region display unit that extends in the movement direction of the radiation image detection unit, is arranged in the vicinity of the subject, and is divided in the movement direction of the radiation image detection unit, and a plurality of regions displayed on the region display unit Based on the input means for receiving the input of the area as the imaging range of the areas, and the information of the area as the imaging range input to the input means, There is obtained a control means for controlling the moving means to move the radiation image detecting means to include all areas that shooting range.

  Here, the “radiation image detecting means” obtains an image signal representing a radiographic image related to a subject by converting incident radiation directly or once into light and then converting it into electric charge and outputting the electric charge to the outside. Can be used.

  There are various types of solid-state detectors. For example, from the aspect of the charge generation process that converts radiation into electric charge, the photoconductive layer detects fluorescence emitted from the phosphor when irradiated with radiation. The signal charge obtained in this way is temporarily stored in the power storage unit, the stored charge is converted into an image signal (electrical signal) and output, or the photoconductive layer is irradiated with radiation. The signal charge generated in step 1 is collected by the charge collection electrode, temporarily stored in the power storage unit, and the stored charge is converted into an electrical signal and output, or the direct conversion type solid state detector that reads the stored charge to the outside From the aspect of the reading process, a TFT reading method that scans and reads a TFT (thin film transistor) connected to a power storage unit, or an optical reading method that reads a reading light (reading electromagnetic wave) by irradiating a detector to the detector. Such as those of news, there is such an improved direct conversion type which is proposed in the Patent Document 1 filed by the present applicant that combines the direct conversion type and the optical readout type.

  In addition, “area display means displaying a plurality of areas divided in the moving direction of the radiation image detection means” means a boundary line that completely divides each area as shown in FIG. 2A, for example. It is not limited to the drawn one, and any scale can be used as long as each area can be uniquely determined, such as a scale that can be uniquely determined as shown in FIG. I do not care.

  In the radiographic image capturing apparatus according to the present invention, the area display means has a facing surface facing the subject extending in the moving direction of the radiation image detecting means, and is arranged between the radiation image detecting means and the subject. It is preferable that the screen is a screen in which a plurality of areas divided in the moving direction of the detection means are displayed.

  In addition, it is preferable that the image generation unit narrows a pattern matching region when a plurality of radiation images are combined as the movement accuracy of the movement unit is higher.

  According to the radiographic image capturing apparatus of the present invention, in the radiographic image capturing apparatus corresponding to the long imaging in a range wider than the detection range of the radiographic image detecting means, it extends in the moving direction of the radiographic image detecting means, and the subject (subject) An area display unit that displays a plurality of areas that are arranged in the vicinity and divided in the moving direction of the radiation image detection unit, and an input of an area that is an imaging range among the plurality of areas that are displayed on the area display unit Based on the receiving input means and the information of the area to be taken as an imaging range input to the input means, the moving means is controlled to move the radiation image detecting means so as to include all the areas to be taken as the radiographic image detecting means. A control unit that performs the imaging range when the subject is at a predetermined imaging position and is compared with a plurality of areas displayed on the area display unit. It is possible to easily set. As a result, there is no need to irradiate the subject with a lamp, a laser marker, or the like, so that the subject is not burdened, and the photographer can more easily check the photographing range as compared with the prior art.

  Further, by displaying a plurality of areas divided in the moving direction of the radiation image detecting means on the partition arranged between the radiation image detecting means and the subject, and using this partition as the area displaying means, it is unnecessary. No member is required, and the present invention can be realized with a simple configuration.

  In addition, the higher the moving accuracy of the moving means, the narrower the pattern matching area when combining a plurality of radiographic images, so that the pattern matching processing is not performed on an unnecessary range. Therefore, the time required for image synthesis can be shortened.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic side view showing a radiographic imaging system as an example of a preferred embodiment of the present invention, FIG. 2 is a front view of a radiation irradiating apparatus of this system, and FIG. 3 is used for a radiographic apparatus of the above system. It is the schematic of a solid state detector.

  This radiographic imaging system 1 includes a radiation irradiation apparatus 2 including a radiation source, a radiation imaging apparatus 3 including a solid detector 20 for detecting radiation, the radiation irradiation apparatus 2 and the radiation imaging apparatus 3. The computer 4 is connected and a monitor 5 is connected to the computer 4.

  The radiation irradiation apparatus 2 includes a base 10, a support column 11 fixed to the base 10, and a radiation irradiation unit 12 containing a radiation source therein. It is attached to be movable in the direction (vertical direction in FIG. 1).

  In the radiation irradiating apparatus 2, the operation of the radiation source and the movement operation of the radiation irradiating unit 12 are all integrated and controlled by a control means (not shown).

  The radiation imaging apparatus 3 includes a base 13, a column 14 fixed to the base 13, a radiographic imaging unit 15 that houses a solid detector 20 therein, and the radiographic imaging unit 15 and a subject. 1 and a handrail 17 fixed to the base 13. The radiographic image capturing unit 15 is attached to be movable in the longitudinal direction (vertical direction in FIG. 1) of the column 14.

  As shown in FIG. 2 (A), a plurality of areas divided in the moving direction of the radiographic image capturing unit 15 (vertical direction in FIG. 2) are displayed on the facing surface facing the subject of the screen 16. The partitions 16 function as area display means. The number of areas to be divided is not limited, but finer control becomes possible as the area is divided into more areas.

  The system of the present embodiment can perform two types of shooting: normal shooting (only one shooting) and long shooting (image combining after shooting multiple times). It is configured so as to be detachable from the base 13, and when taking a long picture, a screen 16 is attached for photographing, and when not taking a long picture, the screen 16 is removed for photographing. In addition, a sensor for detecting the attachment / detachment state of the partition 16 is attached to the base 13.

  The solid state detector 20 is arranged inside the radiographic image capturing unit 15 so that its radiation detection surface is parallel to the radiation incident surface of the radiographic image capturing unit 15.

  As shown in FIG. 3, the solid state detector 20 includes a first conductive layer 24 made of an a-si TFT on a glass substrate 25, a photoconductivity that generates electric charge by receiving radiation and exhibits conductivity. The layer 23, the second conductive layer 22, and the insulating layer 21 are laminated in this order.

  The first conductive layer 24 is formed with a TFT corresponding to each pixel, the output of each TFT is connected to an IC chip 26, and the IC chip 26 is an image signal processing unit (not shown) on the printed circuit board 27. It is connected to the.

  When the solid state detector 20 irradiates the photoconductive layer 23 with radiation when an electric field is formed between the first conductive layer 24 and the second conductive layer 22, the solid state detector 20 enters the photoconductive layer 23. Charge pairs are generated, and latent image charges corresponding to the amount of the charge pairs are accumulated in the first conductive layer 24. When reading the accumulated latent image charge, the TFTs of the first conductive layer 24 are sequentially driven to output an analog signal corresponding to the latent image charge corresponding to each pixel, and this analog signal is processed by image signal processing. The detection is performed for each pixel in the unit, and the analog signals detected for each pixel are combined in the pixel arrangement order. The combined analog signal is AD converted by an AD converter (not shown) to generate a digital image signal. The generated digital image signal is transmitted from the image signal processing unit to the computer 4 via the memory.

  In the radiation imaging apparatus 3, the operation of the solid state detector 20 and the movement operation of the radiation image capturing unit 15 are all integrated and controlled by a control unit (not shown). The control means also has a function of notifying the computer 4 of the attachment / detachment state of the partition 16 on the base 13.

  The computer 4 includes an input device such as a mouse and a keyboard, and functions as an input unit that receives an input of a region to be captured among a plurality of regions displayed on the partition 16 or a photographing input to the input unit. A function as a control unit that controls the radiation imaging apparatus 3 to move the radiation image capturing unit 15 so that the radiation image capturing unit 15 includes all the regions to be captured based on the information of the region to be the range; The function of designating the intensity of the radiation dose in the radiation irradiation device 2 described above, the function of receiving and storing the image signal acquired in the radiation imaging device 3, and the position of the radiation image photographing unit 15 are different from each other. It has a function as an image generation unit that combines a plurality of radiographed images and generates an image in a wider range than the detection range of the radiographic image capturing unit 15. That.

  In addition to this, it also has a function of recording and managing information related to the patient, such as the name and sex of the patient to be imaged, and information related to imaging such as the region to be imaged, radiation dose, and procedure.

  Next, the operation of the radiographic imaging system 1 configured as described above will be described. FIG. 4 is a diagram showing an example of an image photographed by this system.

  In this system, two types of shooting, normal shooting and long shooting, can be performed. Here, a case where long shooting is performed will be described.

  The photographer attaches the partition 16 to the base 13 when performing long shooting. When the screen 16 is attached to the base 13, the radiation imaging apparatus 3 notifies the computer 4 to that effect.

  When the computer 4 receives information indicating that the partition 16 is attached to the base 13 from the radiation imaging apparatus 3, the computer 4 automatically enters the long imaging mode and displays the long imaging menu on the monitor 5.

  The photographer puts the subject at a position facing the partition 16 of the radiation imaging apparatus 3, and then inputs, to the computer 4, an area that is an imaging range among a plurality of areas displayed on the partition 16. Here, it is assumed that the range from A to G in FIG. 2A is selected, and three times of imaging are performed in order to capture the entire range.

  After that, when the irradiation radiation intensity, time, etc. are designated and the first stage of the two-stage radiation exposure switch (not shown) is pressed, the radiation irradiation section 12 and the radiation image capturing section 15 are moved to the first capturing position, When the second stage of the two-stage radiation exposure switch is pressed, imaging starts. This second-stage switch is continuously pressed until all the imaging is completed, and is configured to immediately stop the radiation irradiation when the pressing is canceled halfway.

  When imaging is started, radiation is irradiated from the radiation irradiating unit 12 toward the radiation image capturing unit 15, and the first imaging is performed.

  When radiation is irradiated, latent image charges carrying radiation image information are accumulated in the solid state detector 20. Since the amount of accumulated latent image charge is substantially proportional to the amount of radiation transmitted through the subject, this latent image charge carries an electrostatic latent image.

  After the predetermined time elapses, recording on the solid state detector 20 is stopped and photographing is finished. Then, an analog signal corresponding to the latent image charge is output from the solid state detector 20, and AD conversion is performed in the image signal processing unit to obtain the digital image signal N1. Is generated. The generated digital image signal N1 is transmitted from the image signal processing unit to the computer 4 via the memory.

  When the computer 4 receives the digital image signal N1 from the radiation imaging apparatus 3, the computer 4 displays a preview image of the digital image signal N1 on the monitor 5 and ends the first imaging.

  Thereafter, the radiation irradiation unit 12 and the radiation image capturing unit 15 are moved downward to perform the next imaging. At this time, the radiographic image capturing unit 15 is moved so as to include the previous imaging range slightly (including the overlap), and the radiation irradiating unit 12 is also moved correspondingly. Then, in the same procedure as the first time, the second shooting and the third shooting are performed, and the digital image signals N2 and N3 are acquired.

  In the case of long shooting, when the digital image signals N1, N2, and N3 are acquired, the image is synthesized by the computer 4 and an image having a wider range than the detection range of the solid state detector 20 is generated. In the system, image synthesis is started when two digital image signals adjacent to each other are acquired, not after all of the digital image signals N1, N2, and N3 are acquired.

  As shown in FIG. 4, the images are synthesized by adding and averaging overlapping portions of adjacent images. The synthesis process is not limited to the averaging process, and may be performed by any process such as a weighted addition process.

  At this time, pattern matching was performed line by line in the vertical direction in FIG. 4 to maximize the correlation in order to make the combination position of the second image signal N2 with the first image signal N1 appropriate. Perform synthesis at the location. The area where the pattern matching is performed may be in the same range as the movement accuracy of the moving means for moving the radiation image capturing unit 15.

  For example, when the movement accuracy of the moving means is 1 mm, pattern matching may be performed by shifting the pixels one line at a time in the range of 1 mm above and below around the position where the locations recognized as overlapping portions are overlapped. . By adopting such an aspect, the pattern matching process is not performed for an unnecessary range, so that the time required for image synthesis can be shortened.

  In the present embodiment, when the digital image signals N1 and N2 are acquired, the digital image signals N1 and N2 are combined, a combined image of N1 and N2 is displayed on the monitor 5, and the digital image signal is further displayed. When N3 is acquired, the composite image signal of N1, N2 and the digital image signal N3 are combined, and the composite image of N1, N2, N3 is displayed on the monitor 5.

  At this time, the length in the vertical direction (vertical direction in FIGS. 1, 2, and 4) indicated by the finally obtained composite image signal of N1, N2, and N3 and the vertical direction of the initially set shooting range (FIG. 1). 2 and 4), and if the error is within a predetermined range, it is determined that the composition is normally performed. If the error exceeds the predetermined range, the composition is normally performed. It may be determined that there is no error, and an abnormal message may be displayed on the monitor 5.

  Further, if a marker or the like is displayed at the joint portion in the composite image, it can be easily confirmed whether the image is normally combined.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to the said embodiment, For example, a radiation irradiation part is not restricted to what moves in parallel as mentioned above, The height is It is good also as what fixes only the irradiation direction of a radiation.

  Further, although a TFT readout type is used as the solid state detector, the same effect can be obtained even with an individual detector of another type such as an optical readout type.

Schematic showing a radiographic imaging system according to the invention Front view of the radiation irradiation device of the above system Schematic diagram of a solid state detector used in the radiographic apparatus of the above system The figure which shows an example of the image image | photographed by the said system

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Radiation imaging system 2 Radiation irradiation apparatus 3 Radiation imaging apparatus 4 Computer 5 Monitor 10 Base 11 Prop 12 Radiation irradiation part 13 Base 14 Post 15 Radiation imaging part 16 Screen 17 Handrail 20 Solid state detector

Claims (3)

A radiation image detecting means for taking a radiation image of the subject under irradiation of radiation transmitted through the subject;
Moving means for moving the radiation image detecting means in parallel along the radiation detection surface of the radiation image detecting means;
Image generating means for combining a plurality of the radiographic images taken at different positions of the radiographic image detecting means and generating an image in a range wider than the detection range of the radiographic image detecting means;
A region display unit that extends in the movement direction of the radiation image detection unit, is arranged in the vicinity of the subject, and displays a plurality of regions divided in the movement direction of the radiation image detection unit;
An input unit that receives an input of a region to be a shooting range among the plurality of regions displayed on the region display unit;
Based on the information on the region to be the imaging range input to the input unit, the moving unit is configured to move the radiological image detection unit so that the radiation image detecting unit includes all the regions to be the imaging range. A radiographic imaging apparatus comprising a control means for controlling.   The area display means has a facing surface facing the subject extending in a moving direction of the radiation image detecting means, and is arranged between the radiation image detecting means and the subject, and the radiation image detecting means is disposed on the facing surface. The radiographic image capturing apparatus according to claim 1, wherein a plurality of areas divided in the moving direction are displayed on the screen.   3. The radiographic image capturing apparatus according to claim 1, wherein the image generation unit narrows a pattern matching region when the plurality of radiographic images are combined as the movement accuracy of the moving unit is higher.