JP5036576B2 - Radiation imaging system - Google Patents

Description

  The present invention relates to a radiation image capturing system for capturing a radiation image by irradiating a subject with radiation.

  2. Description of the Related Art In the medical field, radiation image capturing apparatuses that irradiate a subject with radiation and guide the radiation transmitted through the subject to a radiation converter to capture a radiation image are widely used.

  In this case, as a radiation conversion panel constituting the radiation converter, a conventional radiation film in which a radiation image is exposed and recorded, or radiation energy as a radiation image is accumulated in a phosphor and irradiated with excitation light. An accumulative phosphor panel capable of taking out an image as stimulated emission light is known. These radiation conversion panels supply a radiation film on which a radiographic image is recorded to a developing device to perform development processing, or supply a stimulable phosphor panel to a reading device to perform reading processing so that a visible image can be obtained. A radiographic image is obtained.

  On the other hand, in a medical field such as an operating room, in order to perform a quick and accurate treatment on a patient, it is required that a radiation image can be read and displayed immediately from the radiation conversion panel. Radiation conversion using a solid-state detector that converts radiation directly into an electrical signal, or converts radiation into visible light with a scintillator and then converts it into an electrical signal and reads it as a radiation conversion panel that can meet such requirements Panels are being developed.

  By the way, in order to record an appropriate radiation image on the radiation converter, it is necessary to adjust the positional relationship between the subject and the radiation converter with high accuracy.

  Therefore, for example, in the prior art disclosed in Patent Document 1, as shown in FIG. 7, contact sensors 4a to 4d are arranged at four locations on the outer peripheral portion of the radiation converter 2 so that the subject 6 contacts. The imaging region 8 of the radiation converter 2 is set with the contact sensor 4a specified in this way as a reference, and a radiation image is captured by irradiating the imaging region 8 with radiation X from the radiation source 10. ing.

  In the prior art disclosed in Patent Document 2, as shown in FIG. 8, a switch 14 is disposed at the lower part of the imaging table 12 configured to be movable in the direction of the arrow, and the imaging table 12 is moved up and down. The photographing stand 12 is positioned and photographed at the position where the switch 14 is turned on by the subject 6.

  Furthermore, in the prior art disclosed in Patent Document 3, contact detection means is provided in a part of the radiation converter, and when the subject comes into contact with the contact detection means, power is supplied to the radiation converter. So that it can be photographed.

JP 2006-218216 A JP 2002-272732 A JP 2005-173432 A

  In this case, in Patent Documents 1 and 2, the subject 6 can be set in a predetermined imaging region of the radiation converter 2 or the imaging table 12, but the adhesion of the subject 6 to the radiation converter 2 or the imaging table 12 is ensured. There is no guarantee that you can. Therefore, for example, in Patent Document 1, the distance between the radiation source 10 and the radiation converter varies depending on the location, and a clear image may not be obtained.

  Moreover, in patent document 3, only the contact with a radiation converter and a to-be-photographed object is detected, and also in this case, there is no guarantee about adhesion.

  The present invention has been made in view of the above problems, and provides a radiographic imaging system capable of determining whether or not a subject is in close contact with a radiation converter and performing good imaging in an appropriate state. For the purpose.

The radiographic imaging system of the present invention detects a radiation transmitted through a subject and converts it into image information,
A contact state detection means that is disposed in an imaging region of the radiation converter and detects a contact state of the subject with the radiation converter;
The contact state detection means detects the contact state of the subject at at least three points that are not on a straight line, and determines whether or not the subject is in a predetermined contact state with the radiation converter from the detection result. Close contact state determination means,
A determination result notifying means for notifying the determination result of the contact state;
It is characterized by providing.

  According to the present invention, when it is detected that the subject is in contact with at least three points that are not on a straight line in the imaging region of the radiation converter, the subject is within a predetermined range of the radiation converter including these three points. It can be determined that they are in close contact. By irradiating the subject with radiation in this state, a good radiation image can be recorded in the radiation converter at least in the predetermined range.

  FIG. 1 is an explanatory diagram of a radiographic image capturing system 20 according to the present embodiment. The radiographic imaging system 20 includes a radiation source 24 that irradiates a patient 22 (subject) with radiation X having a dose according to imaging conditions, a radiation source control device 26 that controls the radiation source 24, and radiation that has passed through the patient 22. An electronic cassette 28 (radiation converter) having a radiation conversion panel for detecting X, a cradle 30 for charging the electronic cassette 28, and an imaging switch for the radiation source 24, for status confirmation including imaging operations And a console 34 (control device) for controlling the radiation source control device 26, the electronic cassette 28, the cradle 30 and the portable information terminal 32 and for transferring necessary information.

  The radiation source 24, the radiation source control device 26, and the cradle 30 are disposed in the imaging room 36, and the console 34 is disposed in the operation room 38 outside the imaging room 36. Necessary information is transmitted and received between the radiation source control device 26, the electronic cassette 28, the cradle 30, the portable information terminal 32, and the console 34 by wireless communication.

  FIG. 2 is an internal configuration diagram of the electronic cassette 28. The electronic cassette 28 includes a casing 40 made of a material that transmits the radiation X. Inside the casing 40, from the irradiation surface side irradiated with the radiation X, a grid 42 for removing scattered radiation of the radiation X by the patient 22, a radiation conversion panel 44 for detecting the radiation X transmitted through the patient 22, and radiation A lead plate 46 that absorbs X backscattered rays is disposed in order. In addition, a plurality of pressure sensors 48 (contact state detection means) that detect that the patient 22 is in contact with the radiation surface of the casing 40 irradiated with the radiation X are arranged in a matrix at predetermined intervals. These pressure sensors 48 are preferably made of a material that can sufficiently transmit the radiation X.

  Inside the casing 40, there are a battery 50 that is a power source of the electronic cassette 28, a cassette control unit 52 that drives and controls the radiation conversion panel 44 with electric power supplied from the battery 50, and an electrical signal from the radiation X by the radiation conversion panel 44. A transmission / reception unit 54 that transmits / receives a signal including information converted into the cradle 30, the portable information terminal 32, and the console 34 is accommodated. In addition, it is preferable that a lead plate or the like is disposed on the irradiation surface side of the casing 40 in the cassette control unit 52 and the transmission / reception unit 54 in order to avoid damage due to irradiation with the radiation X.

  FIG. 3 is a circuit configuration block diagram of the radiation conversion panel 44. The radiation conversion panel 44 has a photoelectric conversion layer 56 made of a substance such as amorphous selenium (a-Se) that senses the radiation X and generates charges on an array of matrix-shaped thin film transistors (TFTs) 58. After the generated charge is stored in the storage capacitor 60, the TFT 58 is sequentially turned on for each row, and the charge is read as an image signal. In FIG. 3, only the connection relationship between one pixel 62 including the photoelectric conversion layer 56 and the storage capacitor 60 and one TFT 58 is shown, and the configuration of the other pixels 62 is omitted. Amorphous selenium must be used within a predetermined temperature range because its structure changes and its function decreases at high temperatures. Therefore, it is preferable to provide a means for cooling the radiation conversion panel 44 in the electronic cassette 28.

  The TFT 58 connected to each pixel 62 is connected to a gate line 64 extending in parallel to the row direction and a signal line 66 extending in parallel to the column direction. Each gate line 64 is connected to a line scanning drive unit 68, and each signal line 66 is connected to a multiplexer 76 constituting a reading circuit.

  Control signals Von and Voff for controlling on / off of the TFTs 58 arranged in the row direction are supplied from the line scanning drive unit 68 to the gate line 64. In this case, the line scan driving unit 68 includes a plurality of switches SW1 for switching the gate lines 64 and an address decoder 70 for outputting a selection signal for selecting one of the switches SW1. An address signal is supplied from the cassette control unit 52 to the address decoder 70.

  In addition, the charge held in the storage capacitor 60 of each pixel 62 flows out to the signal line 66 through the TFTs 58 arranged in the column direction. This charge is amplified by the amplifier 72. A multiplexer 76 is connected to the amplifier 72 via a sample and hold circuit 74. The multiplexer 76 includes a plurality of switches SW2 that switches the signal line 66 and an address decoder 78 that outputs a selection signal for selecting one of the switches SW2. An address signal is supplied from the cassette control unit 52 to the address decoder 78. An A / D converter 80 is connected to the multiplexer 76, and radiation image information converted into a digital signal by the A / D converter 80 is supplied to the cassette control unit 52.

  FIG. 4 is a configuration block diagram of the radiographic image capturing system 20. The console 34 is connected to a radiology information system (RIS) 82 that comprehensively manages radiographic image information and other information handled in the radiology department in the hospital, and the RIS 82 stores medical information in the hospital. A medical information system (HIS) 84 that is centrally managed is connected.

  A cassette control unit 52 (see FIG. 2) constituting the electronic cassette 28 includes a sensor memory 86 that stores the pressure detected by each pressure sensor 48 as pressure information, and an image that stores the radiation image information detected by the radiation conversion panel 44. And a memory 88. The pressure information and the radiation image information are transmitted to the cradle 30, the portable information terminal 32, and the console 34 via the transmission / reception unit 54. The radiographic image information is transmitted in a compressed state as necessary.

  The control unit 90 of the cradle 30 controls the charge processing unit 92 that performs the charging process of the battery 50 of the electronic cassette 28, while processing the pressure information received from the electronic cassette 28 via the transmission / reception unit 94, and displays the processing result. While displaying on the display part 96, based on a process result, the speaker 98 (alarm alerting | reporting part) is sounded as needed. Note that the radiation image information acquired by the electronic cassette 28 may be displayed on the display unit 96 as a preview image.

  Here, the control unit 90 of the cradle 30 serves as a contact state determination unit that determines whether the contact state of the patient 22 with respect to the electronic cassette 28 is in a predetermined contact state based on the pressure information detected by each pressure sensor 48. Function. The display unit 96 and the speaker 98 function as a determination result notifying unit that notifies the determination result of the contact state that is the processing result.

  The control unit 100 of the portable information terminal 32 supplies an imaging signal generated by the imaging switch 102 that drives the radiation source 24 to the radiation source control device 26 via the transmission / reception unit 104. In addition, the control unit 100 processes the pressure information received from the electronic cassette 28 via the transmission / reception unit 104, displays the determination result of the contact state as the processing result on the display unit 106, and based on the determination result, it is necessary. In response, the speaker 108 (alarm notification unit) is sounded. The display unit 106 may display radiation image information acquired by the electronic cassette 28 as a preview image. Note that the portable information terminal 32 includes an operation unit 110 that can set necessary information.

  The console 34 includes a control unit 112, a transmission / reception unit 114 that transmits and receives necessary information to and from the radiation source control device 26, the electronic cassette 28, the cradle 30, and the portable information terminal 32, and a patient who sets patient information. An information setting unit 116, an imaging condition setting unit 118 that sets imaging conditions necessary for imaging by the radiation source control device 26, an image processing unit 120 that performs image processing on radiation image information transmitted from the electronic cassette 28, and a processing An image memory 122 for storing the radiographic image information, and a display unit 124 for displaying the radiographic image information while displaying the determination result of the contact state of the patient 22 with respect to the electronic cassette 28 based on the pressure information transmitted from the electronic cassette 28. And a speaker 126 that sounds an alarm as necessary based on the determination result.

  The imaging conditions are conditions for determining a tube voltage, a tube current, an irradiation time, and the like for irradiating radiation X having an appropriate dose to an imaging region of the patient 22, for example, an imaging region. And conditions such as a photographing method. The patient information is information for specifying the patient 22 such as the name, sex, and patient ID number of the patient 22. The imaging ordering information including these imaging conditions and patient information can be set directly on the console 34 or supplied to the console 34 from the outside via the RIS 82. The cassette information is cassette ID information for specifying the electronic cassette 28.

  The radiographic image capturing system 20 of the present embodiment is basically configured as described above, and the operation thereof will be described next.

  When capturing a radiographic image of the patient 22, the patient information setting unit 116 of the console 34 is used to set the patient information of the patient 22, and the imaging condition setting unit 118 is used to set necessary imaging conditions. These pieces of information may be acquired from the upstream RIS 82 and HIS 84 via the transmission / reception unit 114.

  The set patient information and imaging conditions are transmitted to the portable information terminal 32 owned by the technician and displayed on the display unit 106. In this case, the engineer can confirm the patient information and the imaging conditions displayed on the display unit 106 of the portable information terminal 32, and can make a desired imaging preparation.

  Therefore, the technician sets the electronic cassette 28 at a desired imaging region of the patient 22. At this time, the pressure sensor 48 in contact with the patient 22 among the plurality of pressure sensors 48 arranged in the casing 40 of the electronic cassette 28 detects a predetermined pressure, and the pressure information is temporarily stored in the sensor memory 86. Is done. Next, the pressure information is transmitted to the cradle 30, the portable information terminal 32, and the console 34 via the transmission / reception unit 54.

  In this case, the control unit 100 of the portable information terminal 32 that has received the pressure information via the transmission / reception unit 104 is detected by, for example, three or more pressure sensors 48a that are not on a straight line, as shown by hatching in FIG. When the pressure is equal to or higher than the predetermined pressure, it is determined that the planar predetermined region 128 of the patient 22 surrounded by the closed curve is in close contact with the electronic cassette 28, and the determination result is displayed on the display unit 106 and imaging is performed. The permission signal is transmitted to the radiation source control device 26 via the transmission / reception unit 104. The engineer who possesses the portable information terminal 32 confirms that the electronic cassette 28 is set in an appropriate state for the patient 22 on the display unit 106, and then starts taking a radiographic image.

  On the other hand, when the number of pressure sensors 48 that detect a predetermined pressure or more among the three pressure sensors 48 that are not on a straight line is two or less, the control unit 100 of the portable information terminal 32 causes the electronic cassette 28 to The electronic cassette 28 is not set in an appropriate state for the patient 22 because it is determined that the surface is not in close contact and is not in an appropriate close contact state, and the determination result is displayed on the display unit 106 and the speaker 108 is sounded. Let the engineer recognize this. In addition, an imaging prohibition signal is transmitted to the radiation source control device 26 to prohibit imaging in an inappropriate state. The engineer adjusts the patient 22 to an appropriate state suitable for imaging according to the determination result.

  Here, as a contact state detection means for detecting the contact state of the patient 22, as shown in FIG. 6, instead of the pressure sensor 48, the transparent electrode 140 is formed on the surface of the casing 40 of the electronic cassette 28a. A touch panel arranged in an array can be used. In this case, the position of the intersection of the transparent electrodes 140 that the patient 22 contacts can be detected, and the close contact state of the electronic cassette 28a with respect to the patient 22 can be determined from the detection result.

  The close contact state of the electronic cassette 28 with respect to the patient 22 is recognized by an engineer using the display unit 96 and the speaker 98 of the cradle 30 as well as the portable information terminal 32, or the display unit 124 and the speaker 126 of the console 34. The engineer may be made to recognize using. Further, the imaging permission signal or the imaging prohibition signal may be transmitted from the cradle 30 or the console 34 to the radiation source control device 26.

  After the electronic cassette 28 is set to an appropriate state for the patient 22, the engineer operates the imaging switch 102 of the portable information terminal 32 to capture a radiographic image. When the imaging switch 102 is operated, the control unit 100 of the portable information terminal 32 transmits an imaging start signal to the radiation source control device 26 via the transmission / reception unit 104. The radiation source control device 26 that has received the imaging start signal controls the radiation source 24 according to the imaging conditions supplied in advance from the console 34 and irradiates the patient 22 with the radiation X.

  Note that while the patient 22 is irradiated with the radiation X, the pressure sensor 48 detects the pressure generated by the patient 22 coming into contact with the electronic cassette 28, and the detection result is displayed in real time in the cradle 30, the portable information terminal 32, and Send to console 34. The cradle 30, the portable information terminal 32, and the console 34 determine the contact state of the patient 22 with respect to the electronic cassette 28 based on the detected pressure. For example, from the change in the contact state during imaging or the change in pressure distribution, When it is determined that the patient 22 has moved, a warning can be notified to the technician using the display units 96, 106, 124 and the speakers 98, 108, 126.

  The radiation X transmitted through the patient 22 is radiated to the radiation conversion panel 44 after the scattered radiation is removed by the grid 42 of the electronic cassette 28, and an electric signal is transmitted by the photoelectric conversion layer 56 of each pixel 62 constituting the radiation conversion panel 44. And is stored as charges in the storage capacitor 60 (see FIG. 3). Next, the charge information that is the radiation image information of the patient 22 held in each storage capacitor 60 is read according to the address signal supplied from the cassette control unit 52 to the line scan driving unit 68 and the multiplexer 76.

  That is, the address decoder 70 of the line scan driving unit 68 outputs a selection signal according to the address signal supplied from the cassette control unit 52 to select one of the switches SW1 and the TFT 58 connected to the corresponding gate line 64. A control signal Von is supplied to the gate. On the other hand, the address decoder 78 of the multiplexer 76 outputs a selection signal in accordance with the address signal supplied from the cassette control unit 52 to sequentially switch the switch SW2, and is connected to the gate line 64 selected by the line scan driving unit 68. Radiation image information, which is charge information held in the storage capacitor 60 of the pixel 62, is sequentially read out via the signal line 66.

  The radiation image information read from the storage capacitor 60 of each pixel 62 connected to the selected gate line 64 of the radiation conversion panel 44 is amplified by each amplifier 72 and then sampled by each sample and hold circuit 74. The signal is supplied to the A / D converter 80 via the multiplexer 76 and converted into a digital signal. The radiographic image information converted into the digital signal is temporarily stored in the image memory 88 of the cassette control unit 52.

  Similarly, the address decoder 70 of the line scan driving unit 68 sequentially switches the switch SW1 in accordance with the address signal supplied from the cassette control unit 52 and holds it in the storage capacitor 60 of each pixel 62 connected to each gate line 64. The radiographic image information as the charge information is read out via the signal line 66 and stored in the image memory 88 of the cassette control unit 52 via the multiplexer 76 and the A / D converter 80.

  The radiation image information stored in the image memory 88 is transmitted to the console 34 by wireless communication via the transmission / reception unit 54, subjected to image processing by the image processing unit 120, and then associated with the patient information. 122. Next, the radiation image information stored in the image memory 122 is displayed on the display unit 124.

  Here, immediately before the radiation conversion panel 44, a pressure sensor 48 is arranged as shown in FIG. If the pressure sensor 48 is made of a material that completely transmits the radiation X, there is no problem, but if the pressure sensor 48 is made of a material that blocks the radiation X to some extent, a shadow of the pressure sensor 48 is formed on the radiation image. . However, this shadow image can be easily removed by image processing in the image processing unit 120 if the pressure sensors 48 are regularly arranged and the transmittance of the radiation X is known in advance. The same applies when a touch panel is used instead of the pressure sensor 48.

  On the other hand, the radiation image information stored in the image memory 88 of the electronic cassette 28 is compressed by the cassette control unit 52 and then transmitted to the cradle 30 or the portable information terminal 32 and displayed on the display unit 96 or 106 as a compressed image. Can be made. The engineer can check the compressed image displayed on the display unit 96 or 106 and determine whether or not re-shooting is necessary. The radiographic image information can be quickly displayed because the amount of information is reduced by being compressed.

  The battery 50 is consumed in the electronic cassette 28 that has been subjected to the radiographic image information imaging process. In this case, the electronic cassette 28 is charged by being mounted on the cradle 30.

  In addition, this invention is not limited to embodiment mentioned above, Of course, it can change freely in the range which does not deviate from the main point of this invention.

  For example, the radiation conversion panel 44 accommodated in the electronic cassette 28 converts the dose of the incident radiation X directly into an electrical signal by the photoelectric conversion layer 56. Instead, the incident radiation X is converted by a scintillator. Once converted into visible light, a radiation conversion panel configured to convert the visible light into an electrical signal using a solid state detection element such as amorphous silicon (a-Si) may be used (Japanese Patent No. 3494683). reference).

  Also, radiation image information can be obtained using a light conversion type radiation conversion panel. In this light conversion type radiation conversion panel, when radiation is incident on each solid detection element arranged in a matrix, an electrostatic latent image corresponding to the dose is accumulated and recorded in the solid detection element. When reading the electrostatic latent image, the radiation conversion panel is irradiated with reading light, and the value of the generated current is acquired as radiation image information. In addition, the radiation conversion panel can erase and reuse the radiation image information which is the remaining electrostatic latent image by irradiating the radiation conversion panel with erasing light (see Japanese Patent Laid-Open No. 2000-105297). .

  Furthermore, a stimulable phosphor panel can also be used as the radiation conversion panel.

It is explanatory drawing of the radiographic imaging system which concerns on this embodiment. It is an internal block diagram of an electronic cassette. It is a circuit block diagram of the radiation conversion panel which comprises an electronic cassette. 1 is a configuration block diagram of a radiographic image capturing system. It is explanatory drawing of the contact | adherence range of the to-be-photographed object detected by the pressure sensor arrange | positioned at an electronic cassette. It is a block diagram of the electronic cassette which has arrange | positioned the touch panel. It is explanatory drawing of position adjustment of the imaging | photography range of the radiation converter which concerns on a prior art. It is explanatory drawing of position adjustment of the imaging stand concerning a prior art.

Explanation of symbols

20 ... Radiological imaging system 22 ... Patient 24 ... Radiation source 26 ... Radiation source control device 28, 28a ... Electronic cassette 30 ... Cradle 32 ... Personal digital assistant 34 ... Console 36 ... Imaging room 38 ... Control room 40 ... Casing 44 ... Radiation Conversion panel 48 ... Pressure sensor 50 ... Battery 52 ... Cassette control unit 82 ... RIS
84 ... HIS
96, 106, 124 ... display units 98, 108, 126 ... speaker 140 ... transparent electrode

Claims (12)

A portable radiation converter comprising: a radiation conversion panel that detects radiation transmitted through a subject and converts the radiation into image information; and a casing made of a material that houses the radiation conversion panel and transmits the radiation;
A contact state detection unit that is disposed in an imaging region of the irradiation surface irradiated with the radiation in the casing and detects a contact state of the subject with the irradiation surface ;
The contact state detecting means detects the contact state of the subject at at least three points that are not on a straight line in the imaging region , and based on the detection result, whether or not the subject is in a predetermined contact state with the imaging region . A contact state determination means for determining whether or not
A determination result notifying means for notifying the determination result of the contact state;
A radiographic imaging system comprising: The system of claim 1, wherein
The radiographic imaging system, wherein the contact state detection means is a plurality of pressure sensors that are arranged in a matrix at predetermined intervals on the irradiation surface and detect pressure applied from the subject. The system of claim 2, wherein
A radiation source for irradiating the subject with the radiation;
While the radiation source irradiates the subject with the radiation, each pressure sensor detects the pressure applied from the subject, and outputs the detected pressure to the contact state determination means in real time,
When the contact state determination unit determines that the subject has moved based on the pressure, the determination unit notifies the determination result via the determination result notification unit. The system of claim 1, wherein
The contact state detecting means, a radiographic imaging system, characterized in that the transparent electrode was constructed by arranging in a matrix, wherein the subject is a touch panel for detecting a position of an intersection of the transparent electrodes in contact. The system according to any one of claims 1 to 4,
A radiographic imaging system, further comprising: an image processing unit that removes the shadow of the contact state detection unit formed in the image information by image processing based on the radiation transmittance of the contact state detection unit. The system of claim 1, wherein
The radiographic imaging system characterized in that the judgment result notifying means is a portable information terminal possessed by an engineer operating the system. The system of claim 1, wherein
The radiation converter further includes a battery housed in the casing and driving the radiation conversion panel ;
The radiographic imaging system characterized in that the judgment result notifying means is a cradle for charging the battery. The system of claim 1, wherein
The determination result notifying means is a control device that controls a radiation source. The system according to any one of claims 6 to 8 ,
The determination result notifying means has a display unit for displaying the determination result. The system according to any one of claims 6 to 8 ,
The radiographic imaging system, wherein the determination result notifying unit includes an alarm notifying unit that notifies the determination result as an alarm. The system of claim 1, wherein
A radiographic imaging system comprising: a radiation source control device that controls an irradiation operation of a radiation source in accordance with a determination result of the contact state by the contact state determination unit. The system of claim 1, wherein
The radiographic imaging system according to claim 1, wherein the contact state determination unit determines the contact state of the subject from the change in the contact state detected by the contact state detection unit.

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