WO2003081282A1

WO2003081282A1 - Radiation image pickup apparatus, radiation image pick up system, image pickup method using radiation, and radiation detector

Info

Publication number: WO2003081282A1
Application number: PCT/JP2002/002962
Authority: WO
Inventors: Hiroshi Kitaguchi; Kazuma Yokoi; Kensuke Amemiya; Yuuichirou Ueno; Norihito Yanagida; Shinichi Kojima; Kikuo Umegaki
Original assignee: Hitachi, Ltd.
Priority date: 2002-03-27
Filing date: 2002-03-27
Publication date: 2003-10-02
Also published as: JPWO2003081282A1; JP4231414B2

Abstract

A radiation image pickup apparatus (3) comprising an X-ray generator (2) and a detector (6) which detects X-rays which has transmitted through a specific part (an object for image pickup) of a patient, and outputs an image thereof. The detector (6) has a configuration in which module detection units (11) having detection elements (21) are arrayed in a holder (12), and the array of the module detection units (11) is determined by a processor (8) according to the size and the shape of the image pickup object which has been input by using an operator console (10). A requested image can be captured rapidly by flexibly meeting the image pickup condition.

Description

Description Radiation imaging apparatus, radiation imaging system, imaging method using radiation, and radiation detector

The present invention relates to a radiation imaging apparatus for imaging radiation, a radiation imaging system including a radiation generator, an imaging method using radiation, and a radiation detector thereof. Background art

As a conventional radiation imaging apparatus using radiation, there are a film method and an imaging plate (IP) method (reference: RDI0IS0T0PES: 44, 433 (1995)). Detectors, which are sensors used in these methods, all have a radiation sensitive thickness of several 10 μπι to several 100 / m, and after imaging, develop or read image information by laser. Is necessary indirect imaging. Further, a radiation imaging apparatus using such an indirect imaging method has a small radiation sensitive thickness and a low radiation detection sensitivity, so that a large amount of radiation is required for imaging. This does not adversely affect the human body, but there was a request to minimize the radiation exposure of patients.

Therefore, in recent years, an imaging method using a flat panel sensor equipped with a phosphor with a thickness of several hundred μππ and a TFT (Thin Film Transistor) as a detector (Reference: IEEJ Technical Meeting Materials; Nuclear Research Meeting, NE-01 -25, P21 (2001)) is attracting attention. This imaging method can obtain a real-time image, and is called direct imaging in contrast to the indirect imaging described above. For this reason, radiation imaging devices capable of direct imaging are being widely used as important devices for mass screening and medical diagnosis. In addition, the main purpose of the conventional radiation imaging apparatus is to perform X-ray imaging of a patient, and the target energy of the radiation is about 100 keV (the effective average energy is about 50 keV). On the other hand, in recent radiological imaging techniques of nuclear medicine, the number of diagnoses of imaging by administering a radioactive substance (RI: Radio Isotope) to a patient is increasing. For such images, Tc-99 m (141 KeV) for gamma cameras and O-l5 and F-18 (51 keV) for PET (Positron Emission Tomography) Is the main RI. However, the above-mentioned RI is a high-energy source compared to the energy of X-rays used for X-ray imaging. Therefore, when imaging such a radiation source with a conventional radiation imaging device, the sensitivity of the detector is further insufficient, so that the imaging time is prolonged and exposure of the patient may become a problem. There is. Also, depending on the type of radiation source, sufficient detection sensitivity cannot be secured, and the required image may not be obtained. From this point of view, there is a demand for the development of a radiation imaging apparatus equipped with a detector having appropriate sensitivity to the radiation source used.

Furthermore, there are many X-ray and nuclear medicine imaging targets that differ in size, from the largest area of the entire breast to the small area of the gall bladder and kidneys. It is manufactured to the size of the largest breast area. However, such large detectors were inconvenient to handle. In addition, when a small site such as a kidney is to be imaged, other unnecessary portions are also imaged. Therefore, there has been a demand that only the necessary site be imaged. Such a demand is prominent in intraoperative local imaging. In order to respond to such demands, it is necessary to prepare all types of radiation sources, detectors that match the area of the imaging target, and radiation imaging devices equipped with such detectors. If three types of energy are used, 30 types of imaging parts (imaging organs, etc.), and 3 types of infants, children, and adults are required, it is necessary to have 270 types of radiation imaging devices in advance. This is not desirable in terms of storage space and management costs.

Therefore, the present invention provides flexible imaging conditions for imaging performed using radiation. The purpose is to be able to respond flexibly and quickly obtain the required image. It is another object of the present invention to minimize the exposure dose of a subject by flexibly responding to imaging conditions. DISCLOSURE OF THE INVENTION.

As a means for solving the above-mentioned problem, there is a radiation imaging apparatus having a radiation detector configured by arranging rectangular detection elements according to an imaging target. The detection element is desirably mounted on the holder as a detection module. If the detection modules are arranged based on the imaging parameters, such as the type of radiation source, the body shape of the imaging target, and the imaging site, it is possible to reliably obtain the required image. Further, as the detection element, any of a compound semiconductor such as CdTe, CZT, and GaAs, or a semiconductor such as Si can be used. Further, it is desirable that the radiation imaging apparatus includes a holder for arranging the detection modules. As such a holder, there is a configuration having a plate for positioning the detection module while sliding the detection module and a long hole. If the gap between the detection elements when the detection modules are arranged in the holder is 2 mm or less, the gap at the time of arrangement can be minimized, and the required image can be obtained reliably. In addition, if a concave portion or a convex portion for assisting the arrangement is provided in the detection module, the arrangement work becomes easy. Here, the detection module arrangement work may be done manually, but a handling mechanism is provided, the detector module is automatically transported from the storage position to the holder, and when assembled, the detector is set up quickly. It becomes possible. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a diagram showing a configuration of a radiation imaging system according to an embodiment of the present invention. FIG. 2 is a conceptual diagram when a radiation imaging device is used as an X-ray imaging device.

FIG. 3 is a configuration diagram of a module detection unit. FIG. 4 is a view taken along line AA of FIG.

FIG. 5 is a schematic diagram illustrating an arrangement of an image of an imaging target and a module detection unit. FIG. 6 is a diagram showing the main medical radiation sources used in nuclear medicine.

FIG. 7 is a diagram showing the relationship between the thickness of the detection element and the amount of absorbed radiation.

FIG. 8 is (a) a side view and (b) a front view showing the structure of the holder.

FIG. 9 is a flowchart of an imaging process in the radiation imaging system.

FIG. 10 is a diagram showing a configuration of the radiation imaging apparatus according to the embodiment of the present invention. FIG. 11 is a perspective view of a module detection unit.

FIG. 12 is a diagram showing an arrangement state of the module detection units shown in FIG. BEST MODE FOR CARRYING OUT THE INVENTION

(First embodiment)

A first embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram illustrating a configuration of a radiation imaging system according to the present embodiment. FIG. 2 is a conceptual diagram when a radiation imaging apparatus is used as an X-ray imaging apparatus.

As shown in Fig. 1, a radiation imaging system 1 is an X-ray generator 2 that emits X-rays as radiation, and an X-ray that is transmitted through a specific part (imaging target) of a patient. The radiation imaging apparatus 3 is included. Further, as shown in FIG. 2, a bed 4 on which the person to be imaged lays, a holding means (not shown) for holding the X-ray generator 2 and the like may be included. The holding means is composed of a C-shaped arm or the like, and the X-ray generator 2 and its detector 6 are fixed to both ends of the arm so as to face each other. It is possible to perform radiation imaging by moving such an arm forward and backward with respect to the imaging target W of the patient, or by rotating the arm in the X and Y directions. In a gamma camera that administers a radioactive substance (RI) to a patient or a radiation imaging device 3 used for SPECT (Single Photon Emission CT) imaging, radiation is emitted from the imaging target itself, so an X-ray generator 2 becomes unnecessary. The radiation imaging device 3 shown in FIG. 1 includes a detector 6 for detecting radiation from an imaging target, a data collection device 7 functioning as an interface for collecting imaging data output from the detector 6, and an imaging device. An operator console 10 that includes a processing device 8 that is a computer that performs image creation and the like and a display device 9 that is an output unit that displays the created captured image. The operator console 10 performs operations of each unit and inputs parameters during imaging. It has. Further, the detector 6 is configured to include a module detection unit 11 that is a detection module that captures an image of an imaging target with one or a plurality of assemblies, and a holder 12 that holds the module detection unit 11. I have.

The configuration of the module detection unit 11 will be described with reference to FIGS. FIG. 3 is a configuration diagram of the module detection unit, and FIG. 4 is a view taken along the line AA of FIG. 3. As shown in FIG. 3, the module detection unit 11 of the detector 6 includes A detector element 21 that generates a charge (electron-hole pair) due to the incident light and forms a rectangular detection surface in a plate shape, a readout circuit 22 for reading out the charge from the detection element 21, and a detection element It has an information controller 23 that functions as an interface to smoothly transfer the huge amount of two-dimensional information from 21 and these are housed in a housing (see FIG. 2) not shown in FIG. It is connected to a data collection device 7 (see FIG. 1) by a cable 24.

As shown in FIG. 4, the detection element 21 has a width W, a length, and a thickness t, and sandwiches the semiconductor 2 la, which is a detection unit that absorbs radiation and generates electric charge, and the semiconductor 2 la. And a force source electrode 21 b and an anode electrode 21 c for applying an electric field to the semiconductor 21 a in order to extract electric charges. As the semiconductor 2 la, for example, a compound semiconductor such as CdTe (cadmium telluride), CZT (cadmium zinc telluride), GaAs (gallium arsenide) or a semiconductor such as Si is used. The cathode electrode 2 lb is provided on the entire surface of the semiconductor 21a using a gold or platinum film. The anode electrode 21c is a signal for each area (pixel) divided into each mesh. It is formed independently so that it can be taken out. For example, when the area of the semiconductor film 21a is 40.times.40 mm and the anode electrode 21c is formed so as to have a mesh of 0.2 mm, the number of nodes becomes 4.0000. The electric charge generated when the radiation is incident on the semiconductor 21a is taken out from each node, read in real time as a detection signal, and becomes information of a two-dimensional radiation image (the above-described imaging data). The total number of pixels of the image created using the detection unit 11 is 400000 pixels. The applied voltage for creating an electric field in the semiconductor element 21a is supplied from the data collection device 7 via the high voltage supply wiring 21d shown in FIG.

The read circuit 22 shown in FIG. 3 is composed of ASIC (application specific IC) and LSI. In order to collect detailed two-dimensional information individually, a bump (fine pole-shaped solder) 25 is used to connect the readout circuit 22 to the anode electrode 21c. The readout circuit 22 and the information controller 23 have a size that does not protrude from the detection element 21 in order to minimize the insensitive part (the part where no image is obtained) when the module detection part 11 is used in combination. is there.

The housing 26 shown in FIG. 2 is for integrally housing and holding the detection element 21 including the above-described high-voltage supply wiring 21 d, the data readout circuit 22, and the information controller 23. And has a thickness of about 0.5 mm to 1 mm. A cable 24 extending from the take-out unit 27 on the back of the module detection unit 11 transmits a signal from the information controller 23 to the data collection device 7 or transmits a signal from the data collection device 7 to the detection element 21. It is used to supply voltage to the power supply. It is desirable that the cable 24 be provided with a connector or the like and be detachable from the take-out portion 27 of the housing 26.

Here, in the present embodiment, an optimal and minimum detector 6 is configured by arbitrarily combining the module detection sections 11, so that it is easy to handle and a small detection suitable for intraoperative imaging or the like. Container 6 is realized. This will be described with reference to the schematic diagram of FIG. 5 as an example. The dimensions of the object to be imaged by the radiation imaging apparatus 3 differ greatly depending on the site (organ or bone). For example, FIG. 5 (a) shows the result of imaging the chest, that is, the moon market W1 as the imaging target. FIG. 2 also shows a combination of the module detection units 11, and each of the square cells corresponds to the detection element 21 of the module detection unit 11. In other words, since the lung W1 is the largest object to be imaged, a total of 16 module detectors 11 in four rows and four columns are mounted in combination with the holder 12 to form a substantially square imaging area. Imaging is being performed. Note that the grid-like area 29 is an insensitive part where an image cannot be obtained due to the housing 26 of the module detection unit 11, so that an actual image cannot be obtained. However, since it has a very small area, it is developed in the processing device 8. 'Sufficient compensation is possible with the processing of the image processing software to be started. In order to minimize this area 29, it is desirable that each module detector 11 be arranged so that adjacent module detectors 11 contact each other. At this time, the region 29 can be minimized when the housing 26 is not provided on the outer periphery of the detection element 21, and the width of the region 29 is “0 mm”. On the other hand, when the outer periphery of the detection element 21 is covered with the housing 26 and the insensitive part is supplemented by image processing, the width of the region 29 is preferably within “2 mni”. This is to prevent the lesion from being overlooked due to the lack of a real image.

Similarly, FIG. 5 (b) shows the result of imaging the stomach W2 using eight module detectors 11 as an imaging target. In this case, the module detection unit 11 combines four, three, and one three rows from the lower part to the upper part of the stomach W 2, so that a total of eight pieces are aligned so that the ends of each row are aligned. If the imaging target is the liver W3 shown in FIG. 5 (c), imaging is performed by combining the module detection units 11 in two rows of three. The imaging target is the module detection unit 11 in the kidney W4 (Fig. 5 (d)), the pancreas W5 (Fig. 5 (e)), and the hand W6 (Fig. 5 (f)). Two single rows, two two rows, and two two rows are combined for imaging. Here, when imaging the pancreas W5, since the shape is elongated, two module detectors 11 in the first row and two module detectors in the second row are used. The module detection unit 11 is combined with the module detection unit 11 shifted by one module detection unit. On the other hand, when the image of the hand W6 is taken, the outer shape of the hand W6 is close to a square, so that the module detection units 11 are combined so that two rows of two hands are arranged in parallel. In addition, in order to minimize the exposure of the patient and obtain a clearer image, it is necessary to optimize the sensitivity of the detector 21, which involves the energy of the radiation source (Fig. 6), This will be described with reference to the relationship between the thickness of the detection element 21 and the amount of absorbed radiation (FIG. 7). Note that the thickness of the force source electrode 21b and the anode electrode 21c shown in FIG. 4 is sufficiently thinner than the semiconductor element 21a, so that the thickness of the detection element 21 is equivalent to the thickness of the semiconductor element 21a for detection. It will be described as.

Figure 6 shows the main medical radiation sources used in nuclear medicine. As is clear from the figure, the energy of the radioactive material (RI) source is large at 80 keV, 150 keV, and 500 keV. It can be divided into three areas. If an X-ray source is used, its energy will be about 75 keV to 140 keV. Since the generated energy of the X-ray source indicates the maximum energy, the effective energy (average energy) is less than about 1/2 of the maximum energy. That is, the effective energy of the X-ray source ranges from 40 to 70 keV. Since the amount of absorption per unit thickness of the detecting element 21 differs depending on the magnitude of the energy, the optimum detecting element thickness should be used for these energy regions, that is, the thickness of the detecting surface should be adjusted according to the energy region. It is desirable to choose. Generally, in order to obtain sufficient imaging sensitivity with respect to the energy of each incident radiation, it is necessary to absorb at least 10% or more. Here, as the thickness (t) of the detection element 21 increases, it is necessary to increase the collection voltage (V) of the charge generated by the incidence of radiation. This relationship is slightly different depending on the material constituting the semiconductor element 21a, but is approximately a relationship of tcV. The SZN for radiation detection depends on the leakage current Id, but the relationship between Id and V is IdV (= ΛΓt). Therefore, the SZN of radiation detection tends to be worse at Ι / Γΐ. In other words, based on these relationships, module detection with the optimum detection element thickness according to the energy of the radiation used for imaging. It turns out that it is necessary to select the outlet 11.

When CdTe is used as the semiconductor element 21a, a relationship between the thickness of the detection element 21 and the amount of absorbed radiation is obtained as shown in FIG. Assuming that the amount of absorbed radiation is 10% or more, a detector element of 5001 ?: 5111111 thickness for 6 ¥, 2 mm thickness for 150 keV, and lmm or less for 80 keV or less can be selected as optimal. . By optimizing the S / N by selecting the detection element thickness for each radiation energy in this way, the imaging time can be shortened, and this has the effect of greatly reducing the exposure of the imaging patient. In the present embodiment, a module detector 11 having a small area is prepared in accordance with the energy of radiation, and the radiation source, the imaging area, the body shape of the subject, etc. are changed by changing the combination of such module detectors 11. The most suitable imaging device suitable for is easily realized.

The holder 12 shown in FIG. 1 is used for arranging the module detectors 11 used for imaging and maintaining the arrangement state. An example of such a holder 12 will be described with reference to FIGS. 8 (a) and 8 (b). FIG. 8 (a) is a side view of the holder, and FIG. 8 (b) is a front view of the holder.

As shown in FIGS. 8 (a) and 8 (b), the holder 12 has a housing 31 which is in contact with at least one of the back and side surfaces of the module detection unit 11. The housing 31 has a bottom surface 32, a side surface 33, a back surface 34, and a top surface 35. It is desirable not to provide a side surface on the surface facing the side surface 33, but a side surface may be provided. The reason why no side surface is provided on the surface facing the side surface 33 is to facilitate attachment of the module detection unit 11 to the holder 12.

The rear surface 34 is a plate with which the rear surface of each module detection unit 11 abuts to arrange the detection elements 21 in the same plane. Elongated holes 36 used for positioning are provided. The elongated hole 36 is formed in accordance with the arrangement direction of the module detectors 11, for example, a holder 12 that can arrange four module detectors 11 in four rows. For example, four rows and four rows of long holes 36 are arranged. The elongated hole 36 does not necessarily need to penetrate the back surface 34. Further, in FIG. 8, the shape is elongated in the horizontal direction, but may be elongated in the vertical direction.

When arranging the module detectors 11 in the holder 12 shown in FIG. 8, as shown by the broken line in the figure, the module detectors 11 should be inserted into the slots 36 with a gap between them. Insert the extraction part 27 of the cable 24, and then slide the module detection part 11 along the elongated hole 36 in the direction of the arrow. When the take-out part 27 comes into contact with one end of the elongated hole 36, the module detection part 11 is positioned, the adjacent module detection parts 11 come into contact, and the vertically continuous module detection parts 11 are arranged. The module detector 11 is slid because it can be easily mounted without touching the detection element 21 at the time of mounting. The back surface 34 may be provided with a means for gripping the take-out portion 27 to prevent the positioned module detection portion 11 from moving, and a fitting portion with the take-out portion 27. It is preferable that the cable 24 of the module detection unit 11 be detachably configured and attached to the extraction unit 27 after the positioning of the module detection unit 11 with respect to the holder 12 is completed.

The holder 12 is a holder capable of imaging the lung W1 in FIG. 5 (a), but the detector 6 is intended for intraoperative imaging, and the detector does not need to image the lung W1. In the case of the container 6 or the like, it is possible to make the holder 12 of an arbitrary shape. Examples of such holders 12 include holders in which module detectors 11 can be arranged in three rows and two columns at maximum, and holders in which four or more module detectors 11 can be arranged in three rows.

The processing device 8 shown in FIG. 1 includes a CPU (Central Processing Unit) and a RAM (Random Access Memory) for performing data processing, a predetermined electric and electronic circuit, and a ROM (Memory) for storing data and programs. It has a storage device such as a read only memory or a hard disk, and may include various drive devices for reading and writing data. The storage device stores a database used when selecting an imaging condition by receiving an imaging parameter described later. This day The database is a table constructed by associating the imaging parameters with the imaging conditions. By performing a database search using a set of imaging parameters as a keyword, a set of imaging conditions can be obtained.

Here, as the imaging parameters, “selection of X-ray imaging and RI imaging”, “type of radiation to be used”, “dose to a patient in the case of RI imaging ′ administration time”, “imaging target”, "Patient's body shape" is an example. Among them, “the type of radiation to be used” is used for selecting the module detecting section 11 having the optimum detecting element thickness. The “dose to the patient in the case of RI imaging / administration time” is used to determine the imaging time. As shown in Fig. 6, a medical RI with a short half-life is used, so the amount of radiation emitted from the RI according to the time elapsed from the time of administration to the time of imaging, that is, emitted from the subject The radiation dose changes. Therefore, by obtaining the administration time, the elapsed time from administration to imaging from the current time of the internal timer is calculated, and the optimal imaging time is determined. The “imaging target” is used to determine the number and combination of the module detectors 11 according to the site as described above. The `` patient's shape '' refers to the patient's height, weight, age, gender, etc., and depending on whether the patient is a child, an adult, or a woman, the measurement position and required modules Used to modify the number and combination of detectors 11.

The imaging conditions include radiation energy and imaging time, the arrangement (combination and number) of the module detector 11, the aperture when the X-ray source is an X-ray source, and the module detector 11 when an RI is used. The conditions for setting the collimator to be arranged are given. The setting conditions of the collimator determine the aperture diameter and its direction based on the position of the imaging target and the energy of radiation. '

Next, imaging processing in the radiation imaging system 1 using the radiation imaging apparatus 3 will be described mainly with reference to the flowchart in FIG.

First, as step S1, the radiation imaging apparatus 3 acquires imaging parameters. This process is performed by the doctor or X-ray imaging technician on the operator console 10 (see Figure 1). ) Is input by inputting various imaging parameters.

In step S2, the processing device 8 automatically determines an imaging condition based on the various imaging parameters input in step S1, and causes the display device 9 to display the imaging condition. That is, the processing device 8 performs a database search using the imaging parameters, determines the number of module detection units 11 based on the size of the imaging target, and determines the number of module detection units 11 according to the shape (type) of the imaging target. To determine the two-dimensional array of In addition, the imaging time is determined as described above, and the module detection unit 11 having a different detection element thickness (detection surface thickness) is determined as necessary.

In step S3, the processing device 8 waits for input of approval / disapproval of the presented imaging condition. In other words, the doctor or X-ray imaging technician checks the imaging conditions displayed on the screen, and if it is determined that correction is necessary (NO in step S3), the process proceeds to step S4. On the other hand, if it is determined that no correction is necessary (YES in step S3), the photographing conditions are approved, and the flow advances to step S5. The confirmation at this time is input from the operator console 10.

The manual correction of the imaging conditions in step S4 can be performed for each item such as the imaging time for the imaging conditions displayed on the screen. By operating the operator console 10, the cursor is moved to the item to be corrected. And enter the required numbers

This is done by selecting from the displayed options. For example, as the arrangement of the module detection unit 11, an array rotated 90 degrees with respect to the array shown in FIG. 5C is displayed as a candidate. After performing the manual correction, the process returns to step S3, and waits for input of approval / denial of the imaging condition.

In step S5, imaging preparation is performed based on the authenticated imaging conditions. The processing device 8 outputs a control signal for moving the holder 12 of the module detection unit 11 to the measurement position facing the target site, and turns on a lamp that notifies the start of imaging. It is desirable that the module detection unit 11 be mounted before the holder 12 is moved. In the following step S6, imaging is performed. In the case of using the X-ray generator 2, the imaging time is counted from the emission of X-rays. In the case of RI, the imaging time is counted from the time when the module detector 11 is arranged at the measurement position. When the imaging is performed, the detection element 21 of the module detection unit 11 generates an electric charge according to the incidence of radiation. This electric charge is transmitted to the processing device 8 for each module detection unit 11 via the cable 24, and the processing device 8 processes the image data and causes the display device 9 to display the image of the imaging site.

Further, in step S7, end processing of imaging is performed. When the imaging time is over, necessary processing such as stopping the output of the X-ray generator 2, leaving the module detector 11 from the measurement position, and stopping the image data collection of the processor 8 are performed. At this time, the captured image is temporarily stored in the processing device 8, and is stored in a storage device, an external recording medium, or output to a printing device as necessary.

Such a radiation detector 6, or a radiation imaging apparatus 3 including the detector 6, or a radiation imaging system 1 including an X-ray generator 2 can be used in a variety of conditions such as a patient's body shape and an imaging site. In this case, the imaging conditions can be easily set, and more practical imaging can be efficiently performed. In the above, acquisition of the imaging parameters, determination of the number and arrangement of the module detectors 11, selection of the detection element thickness performed as necessary, and module detectors 11 to the holder 12 are performed. The process including the sequence of and is the assembly process of the detector 6.

(Second embodiment)

A second embodiment of the present invention will be described in detail with reference to the drawings. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 10 is a diagram schematically illustrating the entire configuration of the radiation imaging apparatus according to the present embodiment. As shown in FIG. 10, the radiation imaging apparatus 51 is connected to a detector 6 including a module detection unit 11 a, lib, 11 c for capturing an image of an object to be imaged and its holder 12, and to the detector 6. Data collection device 7 and a processing device that creates captured images 8, a display device 9 for displaying the created captured image, a module tray 52 for storing each of the module detectors 11a to l1c 52a, 52b, 52c, and a module tray 52a , 52b, 53c, necessary module detectors 11a-: Includes a handling mechanism 53 for taking out L1c and attaching it to the holder 12. Operation of each part and parameters for imaging An operator console 10 is provided for inputting data.

The module detection unit in the present embodiment includes three types of module detection units 11 a, lib, and 11 c having different thicknesses of the semiconductor element 2 la of the detection element 21 shown in FIG. Is prepared. The three types of module detectors 11a, li, and 11c have good sensitivity to the three types of energy (80 keV, 150 keV, and 500 keV) shown in Fig. 7, respectively. 1mm, 2mm and 5mm thick as obtained. In addition, three module trays 52a, 52b, and 52c are also provided to separately store the three types of module detectors 11a, lib, and 11c with different film thicknesses. Have been.

The nozzle ring mechanism 53 includes a gripper-type hand 54 that transports the module detectors 11 a, lib, and 11 c between the module trays 52 a, 52 b, and 52 c and the holder 12. It is composed to include 5 5. Specific examples of such a handling mechanism 53 include a rail laid from the module trays 52 a, 52 b, 52 c to the holder 12, and a traveling vehicle movable on the rail. A multi-indirect robot as a map epilator 55 mounted on a vehicle, and a trolley. Various motors for driving each joint of the multi-indirect robot. The position of the hand 54 is controlled by a control signal output from the processing device 8. For this reason, in the processing device 8, the positions of the holders 12, the positions of the module trays 52a, 52b, 52c, and the module trays 52a, 52b, 52c are provided. The stored module detectors 11a, lib, and 11c are registered in advance. In addition, instead of a multi-indirect robot, a rectangular coordinate robot or other numerical control It is possible to employ a known means for moving 54 in the horizontal and vertical directions. A configuration may be adopted in which the module detectors 11 a to l 1 c are conveyed by rotating the manipulator 55 without providing a rail for moving the manipulator 55 and a traveling carriage.

The module trays 52a, 52b, and 52c have storage holes 56 that can store and store the maximum number of the module detectors 11a, lib, and 11c that can be mounted on the holder 12. That is, if the maximum imaging area is 40 × 40 cm and one imaging area of the module detectors 11 a, lib, 11 c is 4 × 4 cm, one type of module tray 52 a, 52 b, 52 c Each of them has one hundred accommodation holes 56, and stores one hundred module detection units 11a, lib, and 11c, respectively. The orientation and arrangement of the receiving holes 56 can be of any form, but the depth of the receiving holes 56 is such that at least a part of the front of the module detectors 11 a, lib, and 11 c to be stored is It is desirable that the depth is such that it is exposed. This is because the grip 54 grips the side surface of the housing 26 when the handling mechanism 53 conveys the module detectors lla, lib, and 11c.

Here, the processing in the radiation imaging apparatus 51 will be described focusing on the automatic assembly of the detector 6.

First, the radiation imaging apparatus 51 obtains imaging parameters input by the doctor or X-ray imaging technician from the operator console 10 (step S1 in FIG. 9), and based on the imaging parameters, detects the module detection unit 11 a , Li, and 11c, the imaging conditions such as type, number, sink, and array are automatically determined and displayed on the display device 9 (step S2). If the imaging conditions are approved by a doctor or an X-ray imaging technician (YES in step S3) after the imaging conditions are manually corrected as needed (step S4), a control signal is output from the processing unit 8. And preparation for shooting is started (Step S5)

In preparation for imaging, prior to the movement of the detector 6 and the lighting of the lamp, The automatic setup of the detector 6 by the handling mechanism 53 is performed. That is, the processing device 8 includes the types of the module detection units 11 obtained from the imaging conditions approved in step S3 and the arrangement of the module detection units 12 and the module detection units 11a, lib, A control signal is output to the handling mechanism 53 from the position of 1 1 c. Upon receiving the control signal, the handling mechanism 53 grips the hand 54 with the corresponding module detector 11a, lib, 11c, and holds the holder 1 2 from the module tray 52a, 52b, 52c. To a predetermined position. For example, when attaching the module detecting section 11a to the holder 12, the traveling carriage or the manipulator 55 is moved to the position of the module detecting section 11a accommodated in the module tray 52a. In this state, the manipulator 55 is advanced toward the module tray 52a with the hand 54 opened. Then, when the hand 54 is closed and the side surface of the housing 26 (see FIG. 2) of the module detecting section 11a is grasped, the maupilator 55 is retracted from the module tray 52a, and then toward the holder 12. To slide. After that, the height of the module is adjusted by the manipulator 55, and the module detector 11a is mounted on the holder 12 at a predetermined position. When the mounting is completed, the node 54 is returned to the module tray 52a, and the above processing is repeated until all the necessary module detecting sections 11a are mounted on the holder 12.

When the automatic setup of the detector 6 and other imaging preparations are completed, the imaging is performed (step S6). The charge generated by the detection element 21 of the module detection unit 11 in response to the incidence of radiation is processed in the processing device 8 and displayed on the display device 9 as an image of the imaging site. When the required image is obtained, the imaging is terminated (step S7). In the process of assembling the detector 6, the types of detector modules 11a, lib, and 11c and the arrangement of the detector modules are determined based on the input of the imaging parameters, and the handling mechanism 53 automatically determines the type. And arranging the detector modules 11a, lib, and 11c on the holder 12.

Such a radiation imaging apparatus 51 includes module trays 52 a, 52 b, 52 c And the handling mechanism 53, it is possible to automatically assemble the optimal detector 6 based on the imaging conditions. This makes it possible to quickly and easily set the most appropriate imaging device for the imaging region of the patient. Furthermore, the burden on doctors and imaging technicians who perform imaging is greatly reduced, and imaging efficiency can be greatly improved. If a radiation imaging system is constructed by adding the X-ray generator shown in FIG. 1 to the radiation imaging apparatus 51, X-ray imaging can be performed efficiently.

(Third embodiment)

A third embodiment of the present invention will be described in detail with reference to the drawings. The same components as those in the first and second embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

The present embodiment relates to a module detection unit that can easily perform a two-dimensional array. FIG. 11 is a perspective view, and FIG. 12 shows the arrangement state, respectively. The module detector 61 includes a detection element 21, a readout circuit 22, and an information controller 23 as shown in FIG. It has a configuration housed in 66. The housing 66 includes a clamp convex portion 71 for forming a fitted state with another module detecting portion 61, and a clamp concave portion 72 that can be engaged with the clamp convex portion 71 of the same shape on the opposite surface. Yes. In addition, a clamp convex portion 71 and a clamp concave portion 72 are provided at positions different in phase by 90 degrees from the clamp convex portion 71 and the clamp concave portion 72, respectively. The clamp convex portion 71 has a flange portion 74 having a larger diameter than the shaft portion 73. Further, the clamp concave portion 72 is formed by a groove penetrating to the cable 24 take-out side. The inside of this groove has a width substantially equal to the diameter of the flange portion 74 of the clamp convex portion 71.

The two-dimensional array of the module detectors 6 1 having the clamp convex portions 7 1 and the clamp concave portions 7 2 is, for example, a clamp convex portion 7 1 of the module detector 6 1 a located in the middle of the left column in FIG. Adjacent upper module detector 6 Clamp recess of 1 b 7 2 and the clamp concave portion 72 of the module detecting portion 61a is formed by the clamp convex portion of the adjacent module detecting portion 61c of the adjacent side and the convex portion of the lower module detecting portion 61d. 7 Mates with 1. Since the respective module detectors 61 are connected by fitting, the arrangement of the module detectors 61 is facilitated, and the relative displacement of the module detectors 61 can be prevented. Note that, in order to further firmly fix the module detection unit group 62, which is an aggregate of the module detection units 61 combined in an arbitrary shape, a band 63 is wound around the outer periphery of the module detection unit group 62. Is also good. It is desirable that the band 63 has a hook-and-loop fastener or the like, and has a configuration that allows easy adjustment of the length and easy attachment and detachment.

The module detection unit 61 thus combined receives a voltage supply from the processing device 8 as shown in FIG. 1, and generates an electric signal for each radiation incident position. The result of image processing performed by the processing device 8 that has collected the electric signals is output to the display device 9. Further, the combination of the module detectors 61 in a number arrangement is determined by the imaging parameters input from the operation console 10, and the combination of the module detectors 61 is handled as shown in FIG. The mechanism 53 may be configured to perform the processing automatically.

In addition, the present invention can be widely applied without being limited to the above embodiments. For example, in each embodiment, the module detection units 11 and 61 using the semiconductor element 21 a are described. However, even with other detection methods, such as using an ionization chamber instead of the semiconductor element 21a, the same purpose and effect can be similarly exhibited. Also in the first embodiment, a plurality of module trays 52a, 52b, 52 are provided with module detectors 11a, lib, 11c having a plurality of types of detection element thicknesses. May be stored and stored. Since the optimum detector 6 can be formed according to the energy of the radiation, the amount of exposure of the patient can be minimized, and a clearer image can be obtained. Also, the module detector 61 of the third embodiment is added to the first and second embodiments. It is also possible to use.

In addition, a lighting means such as an indicator lamp is provided for each of the module trays 52a, 52b, 52c so that the module detectors 11a, lib, 11c indicated by the imaging conditions can be visually checked. By doing so, it becomes possible to assemble the detector 6 reliably during manual work. Similarly, if lighting means for visually confirming the arrangement of the module detectors 11 determined by the imaging conditions are provided for each array position of the module detectors 11 in the holder 12, the detectors can be surely provided during manual work. 6 can be assembled. As described above, according to the present invention, it is possible to perform optimal radiation imaging corresponding to the body shape of the imaging target (patient, subject), the imaging site, the target radiation source, and the time since RI administration. Therefore, the automatic imaging system that reduces the exposure of the patient can be easily realized.

Claims

The scope of the claims

1. A detector that detects radiation and κ transmitted through the imaging target or radiation emitted from the imaging target, a processing device that performs image processing based on an electrical signal output from the detector, and image processing. An output means for outputting an obtained image.

The detector is formed so that a detection module including a detection element that generates a charge by incidence of the radiation can be arranged in accordance with the imaging target, and has a holder for holding the arrangement of the detection modules. A radiation imaging apparatus characterized in that:

2. An input device for inputting the type of the radiation source, the body shape of the imaging target, and the imaging site as imaging parameters is provided, and the processing device includes a database on the arrangement of the imaging parameters and the detection modules, The radiation imaging apparatus according to claim 1, wherein an arrangement of the detection modules is selected based on the imaging parameters.

3. The detection element according to claim 1, wherein the detection element is configured using any one of a compound semiconductor of CdTe, CZT, and GaAs or a Si semiconductor. Radiation imaging device.

4. The radiation imaging apparatus according to claim 1, wherein the detection elements of the adjacent detection modules are arranged so that an interval between the detection elements is 2 mm or less.

5. The module according to claim 2, further comprising: a module tray accommodating a plurality of the detection modules, and a handling mechanism for transporting the detection modules to the holder in accordance with an arrangement selected based on the imaging parameters. Radiation imaging device.

6. The radiation imaging apparatus according to claim 1, further comprising: an X-ray generator as the radiation source, wherein the X-ray generator is controlled by an output signal from the processing device. Radiation imaging system.

7. Radiation transmitted through and Z or radiation emitted from said object In detecting an image of an imaging target by detecting a line with a detector, the detector includes an assembling step of forming a plurality of modules having a detection surface in combination.

The assembling step includes: determining a number of the detection modules forming the detector based on the size of the imaging target; and detecting the number of the detection modules configuring the detector based on the shape of the imaging target. An imaging method using radiation characterized by including a step of determining a dimensional arrangement.

8. The assembly according to claim 7, wherein the assembling step includes a step of selecting a module having a different detection surface thickness of the module according to the energy of the radiation. Imaging method.

9. A detector used for radiation imaging for detecting radiation transmitted through the imaging target and / or radiation emitted from the imaging target to generate an image of the imaging target,

The detector is formed by arranging a plurality of detection modules each including a detection element that generates a charge by the incidence of the radiation, and the detection module has a protrusion for engaging another adjacent detection module. And a concave portion engageable with a convex portion of the other detection module.

10. A detector used in radiation imaging for detecting radiation transmitted through the imaging target and Z or radiation emitted from the imaging target to generate an image of the imaging target,

A detection module including a detection element that generates an electric charge by the incidence of the radiation; and a holding tool that holds a plurality of the detection modules in an array, and wherein the holding tool includes the detection module (a plate that is in contact with the detection module, and the detection module. A slot for performing positioning by sliding the plate along the plate, wherein the slot is formed in the plate along the arrangement direction of the detection modules. vessel.