JP4415707B2 - Radiation detection device and radiation distribution monitoring device - Google Patents

Description

The present invention relates to a radiation detection apparatus and a radiation distribution monitoring apparatus , and in particular, radiation in a nuclear medicine examination facility by radiation emitted by a examinee (subject, subject) who has been administered RI (radiopharmaceutical). The present invention relates to a radiation detection apparatus and a radiation distribution monitoring apparatus suitable for displaying a distribution .

  Conventional techniques for radiation exposure management in nuclear medicine screening facilities include those that use electronic personal dose dosimeters (alarm meters) and those that use personal film badges and TLDs (thermoluminescence dosimeters) (non-patent literature). 1). In addition, the exposure management system using personal dose dosimeters implemented at nuclear power plants, etc. has a technical example that collects detailed exposure trend information and detailed exposure trend management for workers during radiation work (Patent Literature) There is also 1).

  Many of these conventional technologies set an exposure control value on the dosimeter itself, and when the exposure dose of the worker exceeds or exceeds the control value, an alarm (buzzer) is issued to the worker. The situation is informed and detailed exposure management is performed. Further, regarding the film badge, TLD, etc., the radiation dose is confirmed after the radiation work is completed, and post-processing is performed. Naturally, there is no alarm function for limiting the above-mentioned exposure dose.

  Also, in the nuclear medicine examination facility, area monitors are individually installed in each diagnosis room, and the radiation intensity (dose rate) for each room is monitored in each diagnosis room.

JP-A-1-261802 Radiation Health Management, The University of Tokyo Press, page 98 (1984)

  The radiation source in the nuclear medicine screening facility is a subject to whom RI has been administered. It is difficult to distinguish between examinees who have been administered radiopharmaceuticals including RI by appearance and general patients. In addition, even if the examinee who received the RI is clear, the diagnostic staff (doctor, technician, nurse, etc.) released from the examinee based on the RI dose to the examinee and the time of administration. Diagnosis work is performed by estimating the radiation intensity. The work related to the diagnosis includes the setting of the examinee to the bed, the setting of blood collection, blood pressure, electrocardiogram data collection equipment, etc. In many cases, these operations are performed by estimating the maximum radiation intensity emitted by the examinee. Therefore, there is also a psychological factor that an accurate dose rate cannot be grasped, and it is performed in an excessive radiation protection environment. For this reason, there has been a problem that the diagnosis work cannot be performed smoothly or efficiently.

  In nuclear medicine screening facilities, area monitors are often installed on the walls of diagnostic rooms. The measurement value of the area monitor is the dose value at the area monitor installation location. However, the information that the diagnostic worker wants to know most is the dose rate in the vicinity of the examinee to whom the diagnostic worker approaches. For this reason, the diagnostic worker performs the diagnostic work by estimating the dose rate near the examinee from the measured value. Even in this case, there is a problem that smooth or efficient diagnosis work cannot be performed.

  Particularly, the radiation energy of RI used in nuclear medicine is as small as 511 keV or less, and the dose rate gradient is steep with the distance from the area monitor installation location. Similarly, the half-life of RI used in nuclear medicine is several minutes to several hours, and the time change of the dose rate in the vicinity of the examinee becomes steep even during the time required for nuclear medicine diagnosis (30 to 40 minutes). . This also makes it very difficult to accurately estimate the dose rate in the vicinity of the examinee performed by a diagnostic worker.

  These situations indicate that it is more difficult to properly perform the smooth and efficient diagnostic work described above. Furthermore, in the situation where an accurate dose rate in the vicinity of the examinee cannot be recognized, there is a disadvantage that it leads to a situation where the patient is excessively exposed from the viewpoint of radiation exposure management, and a safety problem occurs.

  An object of the present invention is to provide a radiation distribution monitoring device, a radiation detection device, and an exposure management device capable of confirming a dose distribution in a radiation management area more accurately in a short time.

  A feature of the first invention that achieves the above-described object is that a plurality of radiation detectors having a plurality of radiation detectors and a collimator for limiting the measurement ranges of these radiation detectors are arranged so that each measurement range of each radiation detector is It is to be placed in the radiation control area in the building so that it intersects.

  By arranging such a plurality of radiation detection devices, the dose distribution in the radiation control area can be more accurately and quickly obtained using information obtained based on the radiation detection signals from the radiation detectors of the respective radiation detection devices. Can be sought. Since the graphic information of the dose distribution is displayed on the display device, a more accurate dose distribution in the radiation control room can be confirmed in a short time.

  For example, when applied to a nuclear medicine screening facility, it is possible to easily identify a subject who has been administered a radiopharmaceutical within the radiation control area of the nuclear medicine screening facility, and to accurately grasp the dose distribution around the subject. .

  The feature of the second invention that achieves the above-described object is that a plurality of radiation detectors are arranged in the radiation control area in the building so that the measurement ranges of the radiation detectors cross each other as described above, and each radiation The first information carried by a radiation manager who travels in the radiation management area is created by using the information obtained based on the radiation detection signal from each radiation detector of the detection apparatus to create dose distribution information in the radiation management area. The position information of the radiation manager in the radiation management area is calculated using the position information of the second communication apparatus installed in the radiation management area that receives the identification information of the radiation manager transmitted from the communication device. The radiation dose of the radiation manager is calculated using the dose distribution information at the position.

  Such a second invention can manage the radiation dose of the radiation manager even if the radiation manager does not hold the personal dose meter.

  ADVANTAGE OF THE INVENTION According to this invention, the dose distribution in a radiation control area can be confirmed more correctly in a short time.

  A radiation distribution monitoring apparatus which is a preferred embodiment of the present invention will be described with reference to FIGS.

  First, a radiation detection apparatus 2 that is a mapping monitor constituting the radiation distribution monitoring apparatus 1 (FIG. 2) of the present embodiment will be described with reference to FIG. The radiation detection device 2 includes a plurality of radiation detectors 3, a plurality of collimators 4, and a measurement circuit (measurement device) 6 on a plate-like support member 7. Here, as an example, a radiation detector 2 having six radiation detectors 3, that is, radiation detectors 3a to 3f and four collimators 4 will be described. Each radiation detector 3 is a semiconductor radiation detector in which an anode electrode and a cathode electrode are opposed to a semiconductor element. A measurement circuit 6 is installed on the support member 7. A holding member 8 having a semicircular cross section surrounds the measurement circuit 6 and is attached to the support member 7. A plurality of collimators 4 are radially arranged on the holding member 8 so as to equally divide 180 °. Each collimator 4 is thicker at the mounting portion of the holding member 8 in the radial direction of the holding member 8, and the thickness decreases toward the tip. Around the holding member 8, the radiation detectors 3 are respectively provided in four spaces 9 formed between the collimators 4 and two spaces 10 formed between the collimator 4 and the support member 7. Be placed. These radiation detectors 3 are installed on the holding member 8 and arranged radially. A cover 11 is placed on the support member 7 so as to surround the tip of each collimator 4 and concentrically with the holding member 8. The cover 11 also covers the upper end and the lower end of the collimator 4 (in FIG. 3, the front end surface and the other end surface of the collimator 4).

A detailed configuration of the measurement circuit 6 will be described with reference to FIG. The measurement circuit 6 includes a plurality of signal processing devices 13. These signal processing devices 13 are provided for each of the radiation detectors 3a to 3f. That is, the signal processing device 13a is connected to the radiation detector 3a, the signal processing device 13b is connected to the radiation detector 3b, and the signal processing device 13f is connected to the radiation detector 3f. Although not shown in FIG. 4, the signal processing devices 13c, 13d, and 13e are connected to the corresponding radiation detectors 3c, 3d, and 3e. Each signal processing device 13 includes a preamplifier 14, a linear amplifier 15, a discriminator 16, and a counter (counter) 17, and is provided for each radiation detector 3. The preamplifier 14, the linear amplifier 15, the discriminator 16, and the counter 17 are connected in this order, and the preamplifier 14 is connected to the radiation detector 3. The counter 17 of each signal processing device 13 is connected to the data transmission device 18. A DC high voltage power source 12 applies a DC high voltage between the electrodes of each radiation detector 3.

The radiation detection apparatus 2 is fixed to the side wall in the examination room 22 as shown in FIG. 1 by attaching the support member 7 to the surface of the side wall of the examination room 22 in a nuclear medicine facility, for example, a nuclear medicine examination facility. In a state where the radiation detection device 2 is attached to the side wall, the collimators 4 are arranged in a radial pattern in the horizontal direction. In one examination room 22, two radiation detection devices 2, that is, radiation detection devices 2 a and 2 b are installed on the surfaces of two side walls that are orthogonally adjacent to each other. In the examination room 22, positron emission tomography (Positron Emission)
Tomography) apparatus (hereinafter referred to as PET apparatus) 23 is installed. The PET device 23 includes an imaging device 24 in which a bed 25 on which a patient is placed is inserted and a large number of radiation detectors (not shown) are installed.

As shown in FIG. 2, the radiation distribution monitoring device 1 includes radiation detection devices 2 a to 2 f, measurement circuits 6 a to 6 f, a data collection device 19, a data processing device 20, and a display device 21. These six measurement circuits 6 are separately connected to the individual radiation detection apparatuses 2. The radiation detection devices 2c to 2f are paired in pairs and are fixed to the side wall surface in another examination room as shown in FIG. The number of radiation detection devices 2 can be increased as appropriate by increasing the number of examination rooms and installing them in passages, waiting rooms for examinees, and the like. Each data transmission device 18 of the measurement circuits 6a to 6f connected to the radiation detection devices 2c to 2f is connected to a data collection device 19 connected to the data processing device 20. The display device 21 is connected to the data processing device 20.

  Each collimator 4 of the radiation detection apparatus 2 sets a predetermined independent prospective angle radially. The radiation detectors 3a to 3f of the radiation detection apparatus 2 measure the radiation with the range of the above-described independent prospective angle as a measurement range. Each measurement range of each radiation detector 3 having this directivity will be described with reference to FIG. The measurement ranges for the radiation detectors 3 a to 3 f of the radiation detection apparatus 2 a are the measurement ranges 27 determined by the plurality of boundary lines 26. That is, in the radiation detector 2a, the measurement range 27a for the radiation detector 3a, the measurement range 27b for the radiation detector 3b, the measurement range 27c for the radiation detector 3c, and the radiation detector 3d. The measurement range is 27d, the measurement range is 27e for the radiation detector 3e, and the measurement range is 27f for the radiation detector 3f. Further, the measurement ranges for the radiation detectors 3 a to 3 f of the radiation detection apparatus 2 b are the measurement ranges 29 determined by the plurality of boundary lines 28. That is, in the radiation detector 2a, the measurement range 29a for the radiation detector 3a, the measurement range 29b for the radiation detector 3b, the measurement range 29c for the radiation detector 3c, and the radiation detector 3d. The measurement range 29d is the measurement range 29e for the radiation detector 3e, and the measurement range 29f for the radiation detector 3f. The region 30 of the intersection of each of the measurement ranges 27a to 27f and each of the measurement ranges 29a to 29f is referred to as an intersection region. For example, the intersection area 30 between the measurement area 29c and each of the measurement areas 27a to 27f is the intersection areas C1, C2, C3, C5, and C6.

  As shown in FIG. 2, the radiation distribution monitoring apparatus 1 includes radiation detection apparatuses 2a and 2b installed in an examination room (first examination room) 22, and other examination rooms (second examination room) not shown. Radiation detection devices 2c and 2d installed in a radiation detector, radiation detection devices 2e and 2f installed in an examination room (third examination room) (not shown), a data collection device 19, and a data processing device (display information creation device) 20 and a display device 21. The data collection device 19 is connected to the data transmission device 18 of each radiation detection device 2. The data processing device 20 is connected to the data collection device 19 and the display device 21. These laboratories are radiation control areas in the building of the nuclear medicine screening facility.

  The data processing device 20 has a storage device (not shown). If there is an examinee (radiation source) to which a radiopharmaceutical is administered in one intersection area 30 in each examination room, for example, the examination room 22, the examination is performed based on the intersection area 30 having the highest radiation intensity. Information on the sensitivity of the corresponding radiation detector 3 for all intersection areas in the chamber 2 is stored in the storage device of the data processing device 20. Information on the sensitivity of these radiation detectors 3 is obtained in advance for each case where the radiation source is located in each of the intersection areas 30 in the examination room 22. Such sensitivity information (sensitivity response function) is obtained by positioning a standard radiation source containing a radioactive substance, for example, cesium 137, in each intersection region 30, and by using the radiation detector 3 to emit radiation emitted from the standard radiation source. It can be obtained by detecting.

The operation of the radiation distribution monitoring apparatus 1 in this embodiment will be described. Assume that a subject to whom a radiopharmaceutical is administered enters the examination room 22 and lies on the bed 25. Each of the radiation detectors 3 of the radiation detection devices 2a and 2b detects radiation (for example, γ rays) emitted from the examinee and outputs a radiation detection signal. The processing of the radiation detection signal will be described by taking the radiation detection signal output from the radiation detector 2a of the radiation detection apparatus 2a as an example. The radiation detection signal is amplified by the preamplifier 14 and the linear amplifier 15 and input to the discriminator 16. The discriminator 16 extracts a radiation detection signal at a set level or higher in order to remove noise. The counter 17 counts the radiation detection signal output from the discriminator 16. Information on the count number (radiation intensity) of the radiation detection signal per set time (for example, unit time) in the counter 17 is sent from the data transmission device 18 to the data collection device 19. The data transmission device 18 also transmits the address information of the corresponding radiation detector 3 when transmitting the radiation intensity information. The data collection device 19 outputs the paired radiation intensity information and the detector address information input from the data transmission device 18 of each radiation detection device 2 to the data processing device 20.

Processing executed by the data processing device 20 will be described below. In a certain examination room, for example, examination room 22, radiation detector 3 that detects the highest radiation intensity with radiation detector 2a and radiation detector 3 that detects the highest radiation intensity with radiation detector 2b are input radiation. It is specified based on the intensity information and the detector address information. By specifying these radiation detectors 3, the intersection region 30 having the highest radiation intensity is recognized. Based on the recognized intersection area 30, the sensitivity information of each of the radiation detectors 3 of the radiation detection apparatuses 2a and 2b for all the other intersection areas 30 is retrieved by searching the storage device. Each intersection region 30 is obtained by response matrix calculation using the radiation intensity information in the intersection region 30 where the radiation intensity is highest and the sensitivity information for the corresponding intersection region 30 of each radiation detector 3 obtained by the search. The radiation intensity is calculated. The dose distribution in the examination room 22 is obtained using each calculated radiation intensity. Graphic information (graphic information of contour line intensity distribution 31 described later) for displaying the calculated dose distribution is created. This graphic information is output from the data processing device 20 to the display device 21 and displayed on the display device 21. Using the calculated dose distribution information, graphic information of the dose distribution (contour radiation intensity distribution 31) for displaying this dose distribution is created. The graphic information of the contour radiation intensity distribution (referred to as contour line intensity distribution) 31 is created corresponding to the examinee. The graphic information of the contour line intensity distribution 31 includes the graphic information of the equipment (positron emission tomography apparatus 23) arranged in the examination room 22 and the graphic information of the cross section of the examination room 22 which is a building. Is output to the display device 21 and displayed on the display device 21. The graphic information of the positron emission tomography apparatus 23 and the graphic information of the cross section of the examination room 22 are stored in the storage device of the data processing apparatus 20. It is also possible to apply one of an additive sequential reconstruction method, an ML-EM method [expected value maximization method], and the like to the above-described response matrix calculation. In principle, the radiation intensity of the number of intersection regions 30 corresponding to the product of the number of radiation detectors 3 of the two radiation detection devices 2 provided in the examination room can be calculated.

  The display device 21 in FIG. 2 displays an example of a dose distribution when the highest radiation intensity is detected in the intersection areas C3 and C4. The display of the dose distribution is displayed as graphic information of the contour line intensity distribution 31 that is color-coded. Further, the display device 21 shows the average dose rate and alarm information of each laboratory shown in FIG. 5A, and the enlarged detailed dose distribution around the bed 25 shown in FIG. 5B. It is also possible to display the dose distribution in the nuclear medicine screening facility shown in (c). In addition to the display device 21, it is also possible to separately provide a display device that displays the information shown in FIGS. 5A and 5C exclusively. These dedicated display devices are also connected to the data processing device 20.

  The dose distribution around the bed 25 and the enlarged dose distribution around the bed 25 shown in FIG. 5B displayed on the display device 21 in FIG. 2 are accurate real-time in the vicinity of the examinee who has administered the radiopharmaceutical. Dose distribution. For this reason, workers (radiologists, doctors, nurses, etc.) of a nuclear medicine screening facility can perform an appropriate screening action in consideration of past accumulated exposure doses. Conventionally, the radiation distribution in the examination room was estimated for each examinee and the examination work was performed, so it was assumed that an excessive radiation protection environment was assumed, and it took more time than necessary for the workers to approach the examinee. It was. However, according to the present embodiment, since an accurate dose distribution in the vicinity of the examinee can always be grasped, the worker can perform a smooth or efficient examination operation. This translates into a reduction of 1/2 of the worker's exposure dose in terms of exposure dose, and the screening work efficiency is more than doubled. Above all, it is possible to significantly reduce the psychological burden on the examination work itself of the worker and to ensure safety.

  The display of the dose distribution in the nuclear medicine screening facility shown in Fig. 5 (c) is the radiation control room (central management room) in the nuclear medicine screening facility, and the positions and actions of all examinees in the nuclear medicine screening facility are displayed. Clearly understand. Since the worker can grasp the state before performing the examination work, a safe work procedure related to the examination work can be easily assembled.

  By installing the radiation detection apparatus 2 in a room other than the hallway and the examination room, the dose distribution in the room other than the examination room, the hallway, and the examination room can be obtained in the data processing apparatus 20. By displaying the respective dose distributions in other rooms (for example, waiting rooms) other than the examination room, corridor, and examination room that are radiation control areas, that is, by displaying graphic information of the obtained contour line intensity distribution 31 (see FIG. 6), It is possible to grasp the movement state of the examinee who administered the radiopharmaceutical in the nuclear medicine diagnosis facility. When a certain examinee moves, the graphic information of the contour line intensity distribution 31 created corresponding to the examinee is also moved. The data processing device 20 obtains the movement trajectory of the graphic information of the contour line intensity distribution 31 corresponding to the examinee, and creates the graphic information of the movement trajectory. The data processing device 20 includes the graphic information of the contour line intensity distribution 31 together with the graphic information of the cross section of the nuclear medicine examination facility including the examination room and the graphic information of the equipment in the nuclear medicine examination facility such as the positron emission tomography apparatus 23. The information and the graphic information of the movement locus are output to the display device 21. The display device 21 includes the graphic information of the cross section of the building of the nuclear medicine examination facility and the graphic information of the contour line intensity distribution 31 together with the graphic information of the equipment in the nuclear medicine examination facility such as the positron emission tomography apparatus 23. The graphic information of the movement locus is displayed (see FIG. 6). For this reason, the movement state and movement place in the nuclear medicine examination facility of the examinee who administered the radiopharmaceutical can be grasped. Even if the examinee moves to a place where it is not permitted, the movement can be grasped.

  In the radiation detection apparatus 2, since a plurality of radiation detectors 3 are radially installed on one support member 7, a small range of radiation detectors 3 can cover a wide range in the examination room 22 as a radiation detection region. . Further, since the plurality of radiation detectors 3 are radially installed on one support member 7, the wiring connecting each radiation detector 3 and the DC high-voltage power supply 12 can be shortened. In the radiation detection apparatus 2, since the signal processing apparatus 13 including an amplifier that amplifies a weak radiation detection signal that is an output signal of the radiation detector is installed on the support member 7, the radiation detection signal is influenced by external noise. It becomes difficult to receive. For this reason, the accuracy of the obtained radiation intensity is improved. Further, since the radiation detection device 2 includes the data transmission device 18 that is the output of each signal processing device 13, the number of signal transmission lines connecting the radiation detection device 2 and the data collection device 19 decreases, and nuclear medicine. The time required for the wiring work of the signal transmission line in the examination facility can be shortened. Since each radiation detector 3 and the collimator 4 are arranged around the measurement circuit 6, the support member 7 becomes small and the radiation detector 3 becomes compact. Moreover, since the support member 7 is small, the radiation detection apparatus 2 can be attached to a side wall etc. in a narrow installation space.

The radiation detection device 2 (for example, the radiation detection device 22a) is installed on one side of the examination room, and the other radiation detection device 2 (for example, the radiation detection device 2b) is installed on the other side that intersects with this side. Therefore, a plurality of measurement areas obtained for the respective radiation detectors 3 of the former radiation detection apparatus 2 and a plurality of measurement areas obtained for the respective radiation detectors 3 of the latter radiation detection apparatus 2 intersect each other. The intersection region 30 can be formed. Therefore, using each radiation detection signal output from each radiation detector 3 of both radiation detection apparatuses 2, the dose distribution in the examination room of each intersection area can be obtained more accurately and in a short time. The graphic information indicating the dose distribution in the nuclear medicine examination facility can be displayed on the display device 21 in real time, and the worker can view the graphic information in the nuclear medicine examination facility such as an examination room, a corridor and a waiting room. The dose distribution can be grasped in real time. In particular, the worker can recognize the accurate dose rate distribution in the vicinity of the examinee in real time, and the examination act itself can be performed smoothly and efficiently. That is, since the position where the strong radiation source is located (the position where the examinee is located) can be grasped, the examination action can be performed smoothly. In addition, if the dose of a worker (such as a doctor) increases, the screening act itself may not be possible. Therefore, a screening act that can minimize the exposure of the worker can be efficiently realized.

The exposure management system which is another Example of this invention is demonstrated using FIG.7 and FIG.8. The exposure management system of the present embodiment includes the radiation distribution monitoring apparatus 1 of the above-described embodiment, and an exposure management function is added to the data processing apparatus 20 of the radiation distribution monitoring apparatus 1. As shown in FIG. 7, the worker 35 of the nuclear medicine examination facility carries a portable communication device (first communication device) 36 composed of a microchip. The portable communication device 36 stores the personal management number (personal ID) of the worker (radiation manager) 35 who manages the exposure dose. In a nuclear medicine examination facility, a communication device (second communication device) 38 is installed in each of an examination room, a hallway, a waiting room, and the like. The radiation detection apparatus 2 is also installed in each of an examination room, a hallway, a waiting room, and the like.

  Similarly to the above-described embodiment, the data processing device 20 inputs the respective radiation detection signals output from the respective radiation detectors 3 of the respective radiation detection devices 2, and dose distributions in the respective regions within the nuclear medicine examination facility. Ask for. The data processing device 20 further creates image information of the contour line intensity distribution 31 that is display information based on the obtained dose distribution, and causes the display device 21 to display this information. Assume that a worker 35 moves in an examination room, a hallway, and the like as shown in FIG. Information 37 such as a management number transmitted from the portable communication device 36 of the worker 35 is received by the nearest communication device 38 and transmitted to the data processing device 20 (see FIG. 2). Each of the mobile communication device 36 and the communication device 38 has a wireless device (not shown), and information is exchanged between the mobile communication device 36 and the communication device 38 wirelessly. The data processing device 20 uses the management number information transmitted from each communication device 38 corresponding to the movement of the worker 35 and the position information of the communication device 38 that has output the management number information. Information of the movement route 39 (continuous position information of the moving worker 35) is obtained. The data processing device 20 outputs the created graphic information of the contour line intensity distribution 31 and the graphic information of the movement path 39 to the display device 21. The graphic information shown in FIG. 8 is displayed together with the graphic information of the contour line intensity distribution 31 and the movement path 39 and the graphic information of the cross section of the building of the nuclear medicine examination facility on the floor where the examination room of the nuclear medicine examination facility is located. FIG.

  The data processing device 20 includes information on the dose distribution (contour intensity distribution 31) calculated using information (radiation intensity) obtained based on the radiation detection signal from the radiation detector 3 of the radiation detection device 2, and the above-described information. Using the information of the movement route 39, the exposure amount of the worker 35 on the movement route 39 is calculated every moment, and is integrated with the accumulated exposure amount (see Table 1). This integrated exposure dose is stored in the storage device of the data processing device 20. Table 1 shows the individual ID of each worker who works at the nuclear medicine screening facility and the accumulated exposure dose of each person.

The personal ID and the accumulated exposure dose of each worker are stored in the storage device of the data processing device 20. The position of the worker 35 can be grasped from time to time based on the information on the movement path 39, and the exposure dose at these positions can be calculated using the information of the dose distribution. The calculated exposure dose is added to the integrated exposure dose before the calculation to obtain a new integrated exposure dose. Such a calculation is performed by the data processing device 20. In the present embodiment, the data processing device 20 is a dose distribution information creation device, and is an exposure dose calculation device. The accumulated exposure dose of the worker 35 stored in the storage device is updated from time to time with the newly obtained accumulated exposure dose. The exposure management of the worker 35 can be easily performed by the updated accumulated exposure dose. When a certain worker is likely to exceed the target dose rate by utilizing the accumulated dose information stored in the storage device, the data processing device 20 outputs an alarm signal to the display device 21 and the portable communication device 36. To do. The target exposure dose rate is obtained by the data processing device 20. The alarm signal is transmitted to the portable communication device 36 via the nearest communication device 38. When the mobile communication device 36 receives an alarm signal, the mobile communication device 36 generates a sound from an audio generator (not shown) provided in the mobile communication device 36 and sends the alarm signal to a display device (not shown) of the mobile communication device 36. Display. Thereby, the worker 35 can know that the target exposure dose rate is reached, and can compare with the area not exposed. For this reason, it becomes possible to prevent excessive exposure in advance.

  Also in this embodiment, the effects produced in the above-described embodiment can be obtained. In addition, workers do not need to hold personal dosimeters. In this embodiment, it is possible to perform the exposure management of the worker without the worker holding the personal dosimeter.

  The information on the dose distribution output from the data processing device 20, that is, the information on the contour line intensity distribution 31 is transmitted to the portable communication device 36 via the communication device 38 and displayed on the display device of the portable transmission device 36. It is possible to grasp the dose at the place where you are actually in real time.

  The data processing device 20 may be two data processing devices, one data processing device may be a dose distribution information creation device, and the other data processing device may be an exposure dose calculation device.

  Each embodiment described above is an example applied to a nuclear medicine facility, but can also be applied to a nuclear power plant, a nuclear fuel reprocessing facility, a general radiation handling facility, and the like. In this case, the graphic information of the contour line intensity distribution is combined with the graphic information of the cross section of the building, which is the body of the nuclear power plant, nuclear fuel reprocessing facility, and general radiation handling facility, and the graphic information of the equipment in the building. May be displayed on a display device.

  Three or more radiation detection apparatuses 2 can be installed in one room (for example, an examination room). As the number of radiation detection devices 2 partially installed indoors increases, clearer dose distribution information can be obtained. Further, the number of radiation detectors 3 installed in one radiation detection apparatus 2 is not limited to six, and may be any number as long as it is two or more. As the number of radiation detectors 3 installed in one radiation detection apparatus 2 increases, clearer information on the dose distribution can be obtained.

  Each of the above-described embodiments has been described as an example in which a plurality of radiation detection devices 2 are installed on the side wall. However, one radiation detection device 2 is installed on the side wall and the other radiation detection device 2 is installed on the side wall. May be.

  As described above, by adopting the nuclear medicine radiation distribution monitoring device of each embodiment, the diagnostic worker can recognize the accurate dose rate distribution in the vicinity of the screening patient in real time, and the diagnostic action itself should be performed smoothly and efficiently. Will be able to.

It is explanatory drawing which shows the state which has arrange | positioned two radiation detection apparatuses shown in FIG. 3 in a test room, and the measurement range of each radiation detection apparatus. It is a block diagram of the radiation distribution monitoring apparatus which is one preferable Example of this invention. It is a detailed block diagram of the radiation detection apparatus shown in FIG. It is a detailed block diagram of the measurement circuit shown in FIG. It is explanatory drawing which shows the example of the display information displayed on a display apparatus. It is explanatory drawing which shows the example of a display of the movement state of the examinee in a nuclear medicine medical examination facility. It is explanatory drawing which shows the communication state of the information between the portable communication apparatus attached to the worker, and the communication apparatus attached to the nuclear medicine examination facility. It is explanatory drawing which shows the principle of the exposure management of the worker who does not have a personal dosimeter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Radiation distribution monitoring apparatus, 2, 2a-2f ... Radiation detection apparatus, 3, 3a-3f ... Radiation detector, 4 ... Collimator, 6, 6a-6f ... Measurement circuit, 7 ... Support member, 8 ... Holding member,
DESCRIPTION OF SYMBOLS 11 ... Cover, 13, 13a, 13b, 13f ... Signal processing device, 17 ... Counter, 18 ... Data transmission device, 19 ... Data collection device, 20 ... Data processing device, 23 ... Positron emission tomography device, 26, 28 ... boundary lines 27, 27a to 27f, 29, 29a to 29f ... measurement area, 30, C1 to C6 ... intersection area, 36 ... portable communication device, 38 ... communication device, 39 ... movement path.

Claims (7)

A plurality of measurement ranges intersect each other, and a plurality of them are placed in the radiation control area in the building so as to have an intersection area.
A support member, said support member a plurality of radiation detectors cross section mounted is installed in the holding member of the semicircle, are placed radially to the holding member formed in the support member, said plurality of radiation A collimator for limiting the measurement range of the detector,
The plurality of radiation detectors are arranged radially, and the collimator has a larger thickness at the mounting portion of the holding member with respect to the radial direction of the holding member, and the thickness decreases toward the tip. A radiation detection apparatus characterized by the above. A plurality of signal processing devices that generate radiation intensity information, which is information obtained based on radiation detection signals output from the radiation detector, and are separately connected to the plurality of radiation detectors;
An information transmission device that transmits each radiation intensity information output from each signal processing device,
The radiation detection apparatus according to claim 1, wherein the plurality of signal processing apparatuses and the information transmission apparatus are installed on the support member.   The radiation detection apparatus according to claim 2, wherein the plurality of radiation detectors and the collimator are arranged around the plurality of signal processing apparatuses.   The radiation detection apparatus according to claim 2, wherein the holding member is disposed around the plurality of signal processing apparatuses and the information transmission apparatus, and the plurality of radiation detectors and the collimator are installed on the holding member. A plurality of radiation detection devices according to claim 1 are arranged, the measurement ranges of the radiation detection devices of each other intersect, and the radiation detection devices are arranged in a radiation management area in the building so as to have an intersection area,
Using information obtained based on the radiation detection signal output from each radiation detector of each radiation detection device, a display information creation device that creates graphic information of a dose distribution in the radiation management area,
A radiation distribution monitoring device comprising: a display device that displays graphic information of the dose distribution.   The radiation distribution monitoring device according to claim 5, wherein the display information creation device outputs graphic information of the building to the display device. A plurality of radiation detection devices according to claim 1 are arranged, the measurement ranges of the radiation detection devices of each other intersect, and the radiation detection devices are arranged in a radiation management area in the building so as to have an intersection area,
Using the information obtained based on the radiation detection signal output from each radiation detector of each radiation detection device, the first dose distribution caused by the subject to which the radiopharmaceutical is administered in the radiation management area. A display information creating device that creates figure information and creates second figure information of a movement locus of the first figure based on the movement of the first figure information;
A radiation distribution monitoring apparatus comprising: a display device that displays the first and second graphic information.

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