JPH09281241A - Gamma-ray detector and nuclear medical diagnostic device using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable uses in various styles and increase compatibility with various photography systems by providing two 1st and 2nd gamma-ray detection parts of the same constitution in the same structure. SOLUTION: The 1st and 2nd gamma-ray detection parts 1 and 2 have semiconductor sensors 3 which detect gamma rays and output them as electric signals and are provided with collimators 5 limiting the incidence directions of the gamma rays on their gamma-ray incidence sides, and at the output of each semiconductor sensor 3, a preamplifier 7, an analog-digital converter 9, and an energy spectrum gathering part 11 are provided. For an energy spectrum corrected by a waveform processing part 13 of a main body as required, a wave height analysis part 15 finds the total of counted values in a window of interest corresponding to an object isotope. An image processing part 17 reconstitutes the living body distribution of the gamma rays as image data according to the total counted value and position information on the semiconductor sensors 3 and complements the data in conformity with the matrix size of an image display part 23. Then a light and shade display of the living body distribution of the gamma rays is made at the image display part 23 thorugh an image memory 19 and a data processing part 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gamma ray detector for detecting gamma rays emitted from a radioisotope (hereinafter referred to as RI) injected into a living body and a gamma ray distribution in the body using the gamma ray detector. A nuclear medicine diagnostic device.

[0002]

2. Description of the Related Art A nuclear medicine diagnostic apparatus is characterized by detecting one gamma ray at the time of decay of RI using a single photon nuclide and obtaining a two-dimensional gamma ray accumulated image based on the detected data. By using a scintillation camera (gamma camera) and a pair of gamma rays emitted in opposite directions when a positron disappears using a positron nuclide, a two-dimensional accumulated image of gamma rays is obtained by specifying the emission location. It is classified as a positron camera, which is characterized by that.

Among them, an Anger type camera is predominantly used as a gamma ray detector of a scintillation camera, but recently, a positron camera for detecting the position of a positron nuclide has emerged using an Anger type scintillation camera with two detectors facing each other. I'm doing it.

The Anger type camera detects fluorescence generated by a scintillator typified by NaI by a plurality of photomultiplier tubes (PMT) densely arranged via a light guide, and detects the detected signal. Position calculation processing and energy value calculation processing are performed. The position calculation processing is to obtain the incident position of the gamma ray by weighting and adding each photomultiplier tube to one gamma ray event. The energy calculation process is to calculate the energy value of gamma rays by adding the outputs of all photomultiplier tubes. However, the photomultiplier tube has a problem that the detection accuracy is lowered due to variations in the detection sensitivity depending on the position on the light detection surface, changes in the sensitivity over time, drifts due to temperature, and the like. Also, in order to prevent this decrease in detection accuracy,
It required various correction circuits.

Further, since the conventional gamma ray detector uses a photomultiplier tube, there is a problem that the gamma ray detector becomes thick. Also, because a photomultiplier tube is used,
There is a problem that the dead space in the gamma ray detector increases, the gamma ray detector as a whole becomes large, and the weight of the gamma ray detector becomes several hundred kg. Due to such size and weight, it is difficult to set the detector position according to various clinical purposes, and the collection purpose is limited,
There is a problem that the device for supporting and moving the gamma ray detector becomes large in scale and expensive even when a wide range of collection is possible. In addition, since the detector is large, the patient may be required to have a painful posture when aligning the position of the gamma ray detector.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a nuclear medicine diagnostic apparatus capable of obtaining a biodistribution of a nuclide with high accuracy and having high compatibility with various imaging targets and imaging methods. That is.

[0007]

SUMMARY OF THE INVENTION The gamma ray detector of the present invention comprises two semiconductor sensors for detecting gamma rays.
It comprises a first gamma ray detector arranged two-dimensionally and a second gamma ray detector having a two-dimensional array structure of a plurality of semiconductor sensors for detecting gamma rays.

Further, the nuclear medicine diagnostic apparatus of the present invention comprises a first gamma ray detecting section in which a plurality of semiconductor sensors for detecting gamma rays are two-dimensionally arranged, and a plurality of semiconductor sensors for detecting gamma rays. A second gamma ray detector having a two-dimensional array structure, and means for imaging the in-vivo distribution of gamma rays based on the output of the first gamma ray detector and the output of the second gamma ray detector. To do.

Further, the nuclear medicine diagnostic apparatus of the present invention includes a gamma ray detecting section in which a plurality of semiconductor sensors for detecting gamma rays are two-dimensionally arranged, and the gamma ray detecting section at a predetermined position with respect to the subject. The gamma ray detector is provided for the purpose of disposing the gamma ray detector, and includes a support mechanism to which the gamma ray detector is detachably attached, and a means for imaging the in-vivo distribution of gamma rays based on the output of the gamma ray detector.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION R using a single photon nuclide
Among the nuclear medicine diagnostic devices that detect one gamma ray at the time of I decay and display it as a two-dimensional image, SPECT (Single P
hoton Emission Computed Tomography) Describes an example in which one system can perform collection, whole body collection, normal static collection, mammo collection, thyroid collection, and PET collection by installing two detectors facing each other. .

FIG. 1 shows the configuration of the nuclear medicine diagnostic apparatus according to this embodiment. FIG. 2 shows a schematic structure of the gamma ray detection unit of FIG. The nuclear medicine diagnostic apparatus is roughly composed of a gamma ray detector for detecting gamma rays from RI and a main body as a signal processing system for imaging the biodistribution of RI based on the output of the gamma ray detector. It

The gamma ray detector has a first gamma ray detecting section 1 and a second gamma ray detecting section 2. The first gamma ray detection unit 1 and the second gamma ray detection unit 2 have the same configuration and structure. Therefore, the configuration and structure of the first gamma ray detection unit 1 will be described, and the description of the configuration and structure of the second gamma ray detection unit 2 will be omitted.

The first gamma ray detector 1 has a plurality of semiconductor sensors 3 for detecting gamma rays and outputting them as electric signals. For the semiconductor sensor 3, for example, CdZnTe is adopted. The plurality of semiconductor sensors 3 are, for example, 12.7.
It is densely and two-dimensionally arranged in a rectangular plane of cm × 25.4 cm. On the gamma ray incident side of the plurality of semiconductor sensors 3, a collimator (COL) for limiting the gamma ray incident direction is provided.
LIMATOR) 3 is provided. In order to collect the energy spectrum for each semiconductor sensor 3, a pre-amplifier (PRE-AMP) 7 and an analog-digital converter (AD
C) 9, an energy spectrum collection unit (ESA) 11 is provided.

The energy spectrum is defined as a distribution obtained by decomposing the frequency (corresponding to the number of incidents) of gamma rays incident within a fixed time with respect to the energy axis. Practically, the energy band of 0.5 to 2 KeV is associated with one channel, and the frequency is counted for each channel.

One gamma ray is incident on one semiconductor sensor 3. The position of this one semiconductor sensor 3 is directly determined as the incident position of the gamma ray. The output of the semiconductor sensor 3 completely directly reflects the total energy of the incident gamma ray.

A plurality of energy spectrum collecting units 11
Each has a semiconductor memory and a corresponding semiconductor sensor 3.
Gamma rays are incident on the analog-digital converter 9
Each time a signal is output from the controller, the controller controls the semiconductor memory so that the value of the address corresponding to the channel of the energy band including the energy level is sequentially increased by 1.

The waveform processing section 13 of the main body performs spectrum shape estimation processing on each energy spectrum collected by each energy spectrum collection section 11 in order to remove statistical noise components. In addition, in order to remove the scattering components and crosstalk components from other nuclides in the spectrum estimated by this shape estimation processing, the spectrum estimated by the processing for removing scattered radiation components and crosstalk components such as the trapezoidal approximation method Give. The wave height analysis unit 15 obtains the total count value in the window of interest corresponding to the target nuclide for each energy spectrum corrected by the waveform processing unit 13. The image processing unit 17 reconstructs the biological distribution of gamma rays as image data based on the total count value and the position information of the semiconductor sensor 3, and needs the image data so as to correspond to the matrix size of the image display unit 23. Interpolate accordingly. The image processing unit 17 is provided with an arrangement input means for inputting arrangement information of the first gamma ray detector 1 and the second gamma ray detector. The image processing unit 17 obtains the position information of the semiconductor sensor 3 based on the input to this arrangement input means. This image data is displayed in gray scale as a biometric distribution of gamma rays on the image display unit 23 via the image memory 19 and the data processing unit 21.

The first gamma ray detecting section 1 and the second gamma ray detecting section 2 may be used individually or as shown in FIG.
As shown in FIG. 3A, the long sides of the first gamma ray detecting unit 1 and the second gamma ray detecting unit 2 may be in contact with each other to form one gamma ray detector, or as shown in FIG. One gamma ray detector may be configured such that the short sides of the first gamma ray detector 1 and the second gamma ray detector 2 are in contact with each other.

When the long sides are in contact with each other as shown in FIG. 3A (hereinafter referred to as horizontal placement), the long axes of the first gamma ray detecting section 1 and the second gamma ray detecting section 2 are arranged in parallel. ,
The combined detection surface of the first gamma ray detector 1 and the second gamma ray detector 2 has a substantially square shape. In the case where the short sides are in contact with each other as shown in FIG. 3B (hereinafter referred to as vertical orientation), the short axes of the first gamma ray detecting unit 1 and the second gamma ray detecting unit 2 are arranged in parallel, and The combined detection surface of the gamma ray detection unit 1 and the second gamma ray detection unit 2 has a rectangular shape. In this way, the first gamma ray detecting unit 1 and the second gamma ray detecting unit 2 are used individually or in parallel in the vertical or horizontal direction, so that the first gamma ray detecting unit 1 and the second gamma ray detecting unit are used. It is possible that the shape and size of the detection surface as a whole or a combination of the two and the two can be preferably modified and used according to the type and position of the imaging target site and the size.

FIG. 4 (a) shows a vertical frame for supporting and fixing the first gamma ray detecting section 1 and the second gamma ray detecting section 2 in a horizontal arrangement. The horizontal frame 35 supports and fixes the first gamma ray detector 1 and the second gamma ray detector 2 so that the long sides of the first gamma ray detector 1 and the second gamma ray detector 2 are in contact with each other. To do. First gamma ray detector 1 and second gamma ray detector 2
On the two side surfaces adjacent to each other, a protruding rail 33 is formed. The rail 33 is provided on the inner surface of the frame 35.
A groove 37 into which is inserted is formed. The first gamma ray detector 1 and the second gamma ray detector 2 are inserted into the frame 35 along the groove 37 in a state where the long sides where the rail 33 is not formed are aligned with each other. A lid 36 forming one side of the frame 35 is provided so as to be openable and closable, and the first gamma ray detecting unit 1 and the second gamma ray detecting unit 2 are closed and fixed in a state of being inserted in the frame 35.

As a result, the first gamma ray detecting section 1 and the second gamma ray detecting section 2 are stably held in a horizontal state, and the first gamma ray detecting section 1 and the second gamma ray detecting section 2 are Since the long sides on which the rail 33 is not formed can be aligned with each other, the two-dimensional arrays of the two semiconductor sensors 3 are continuously connected. Such a horizontal arrangement is used for plane collection of the head or SPECT collection that requires a detection surface close to a square.
It is particularly useful for plane acquisition of the heart, SPECT acquisition, and the like.

FIG. 4 (b) shows a vertical frame for supporting and fixing the first gamma ray detecting unit 1 and the second gamma ray detecting unit 2 in the vertical arrangement. The vertical frame 39 supports and fixes the first gamma ray detector 1 and the second gamma ray detector 2 so that the short sides of the first gamma ray detector 1 and the second gamma ray detector 2 are in contact with each other. To do. A groove 40 into which the rail 33 is inserted is formed on the inner surface of the frame 39. The first gamma ray detector 1 and the second gamma ray detector 2 are inserted into the frame 39 along the groove 40 in a state where the short sides where the rail 33 is not formed are aligned. A lid 41 forming one side of the frame 39 is provided so as to be openable and closable, and the first gamma ray detecting unit 1 and the second gamma ray detecting unit 2 are closed and fixed in a state of being inserted in the frame 39.

As a result, the first gamma ray detecting unit 1 and the second gamma ray detecting unit 2 are stably held in the vertical state, and the first gamma ray detecting unit 1 and the second gamma ray detecting unit 2 are Since the short sides on which the rail 33 is not formed can be aligned with each other, the two-dimensional arrays of the two semiconductor sensors 3 are continuously connected. Such a vertical arrangement combines a wide range of whole body collection by combining with a supporting mechanism that movably supports the gamma ray detector in the vertical arrangement.
It is suitable for SPECT acquisition and plane acquisition. still,
The moving method at this time may be either a scan method in which the movement is performed simultaneously with the collection, or a step movement method in which the collection and the movement are alternately performed.

When performing whole body collection, the gamma ray detector placed vertically should be placed so that the short axis of the gamma ray detector placed vertically is parallel to the body axis of the patient (direction connecting the head and foot). Support with a support mechanism. Next, the vertically placed gamma ray detector is sequentially moved in the body axis direction (the direction connecting the head and the foot) to collect gamma rays. During this movement, keep the distance between the gamma ray detector and the subject almost constant,
The gamma ray detector may be moved toward and away from the subject. By performing this operation from the foot part to the head part of the patient, whole body collection (whole body collection) can be performed.

When performing a wide range of SPECT acquisition,
The vertical gamma ray detector is supported by the support mechanism such that the long axis of the vertical gamma ray detector is parallel to the body axis direction of the patient. Next, the vertically placed gamma ray detector is sequentially rotated around the body axis to collect gamma rays.
A wide range of SPECT acquisition can be performed by performing this acquisition while rotating 360 degrees, for example.

The above-described frames 35 and 39 have a structure in which the side surface portion and the rear surface portion are covered with a gamma ray shielding material in order to prevent gamma rays from entering the peripheral edge of the semiconductor sensor 3 from the side surface and the rear surface. This gamma ray shielding material has a two-layer structure in which a material that shields gamma rays such as lead is attached to a highly rigid material. The gamma ray shielding material may be formed of a single material such as lead that shields gamma rays.

In the above, the first gamma ray detector 1
Although the frame in which the first gamma ray detecting unit 1 and the second gamma ray detecting unit 2 are used independently has been described, the frame in which the first gamma ray detecting unit 1 and the second gamma ray detecting unit 2 are combined to form one gamma ray detector has been described. A frame for fixed support may be used. It should be noted that any one of vertical placement, horizontal placement, and single placement may be input to the input means of the image processing unit 17 as detector placement information. This input may be manually input by the operator, or a detector for detecting the arrangement may be provided in the gamma ray detection unit and the output of this detector may be input.

FIG. 5 (a) shows a front view of a supporting mechanism for supporting the first gamma ray detecting section 1 and the second gamma ray detecting section 2. FIG. 5B shows a view of the support mechanism of the first gamma ray detecting unit 1 and the second gamma ray detecting unit 2 as seen from above. FIG. 6 shows a first gamma ray detector 1 and a second gamma ray detector 2.
3 is a perspective view of the support mechanism of FIG.

The first gamma ray detecting section 1 includes an arm 261.
It is supported by the rotating ring 251 via. The second gamma ray detecting section 2 includes a rotating ring 2 via an arm 262.
It is supported by 52. The rotating ring 251 and the rotating ring 252 are rotatably attached to the frame independently of each other (C, C '). The gantry is constructed so that it can move on rails installed on the floor. By moving on the rail, the gantry moves along the body axis direction of the subject. The arms 261 and 262 are provided on the rotating rings 252 and 252 so that the arms 261 and 262 can swing vertically and horizontally ((a, a '), (b, b')). Arms 261 and 26
2 has a structure in which its arm length can be changed and which is expandable and contractible, or slidable so that the rotating rings 252, 252
(D, d '). First gamma ray detector 1
Is provided at the tip of the arm 261 through a free joint mechanism such as a universal joint mechanism so that the orientation of the detection surface can be freely changed with respect to the axial direction of the arm 261. Similarly, the second gamma ray detection unit 2 also has an arm 26.
It is provided at the tip of the arm 262 via a free joint mechanism such as a universal joint mechanism so that the orientation of the detection surface can be freely changed with respect to the axial direction of 1. An attachment / detachment mechanism is provided at the tips of the arms 261 and 262 so that the first gamma ray detector 1 and the second gamma ray detector 2 can be easily attached and detached. The first gamma ray detection unit 1 and the second gamma ray detection unit 2 can be detached from the support mechanism and used for hand carry collection (collection performed while the gamma ray detection unit is held by hand) or mammo collection. is there. The first gamma ray detecting unit 1 and the second gamma ray detecting unit 2 are attached to the arms 261 and 262 while being housed in the frame.

With such a support mechanism, various parts and photographing methods can be dealt with as follows. Fig. 8 shows the plane of the whole body, chest, abdomen, etc.
As shown in (a) and FIGS. 9 (a) and 9 (b), the first gamma ray detecting unit 1 and the second gamma ray detecting unit 2 can be set in a vertically placed state and used. In this case, the arm 2 with the first gamma ray detecting unit 1 and the second gamma ray detecting unit 2 accommodated in the vertical frame 39 described above is accommodated.
It may be attached to 61 and arm 262. Further, at the time of plane view of the head or SPECT imaging, as shown in FIG. 8B, the first gamma ray detecting unit 1 and the second gamma ray detecting unit 2 may be set in a horizontal state and used. it can. In this case, the first horizontal frame 35
The gamma ray detecting unit 1 and the second gamma ray detecting unit 2 may be attached to the arms 261 and 262 while being accommodated therein. Further, when it is desired to improve the collection efficiency of the heart, as shown in FIG. 7, a space between the first gamma ray detection unit 1 and the second detection unit 2 is a substantially L-shape with an angle of 90 ° to 150 °. You can place it in the and collect it. In this case, the first gamma ray detecting unit 1 and the second gamma ray detecting unit 2 are individually housed in the frame, respectively attached to the arms 261 and 262, the rings 251 and 252 are rotated, and the arms 261 and 262 are moved. , The position is set by a combined operation of the rotations of the gamma ray detection units 1 and 2.

The support mechanism for collecting mammos will be described below. FIG. 10 is an external view of a support mechanism for collecting mammoths. The pedestal 42 is a pedestal installed on the floor. Support pillar 4
A column 3 is fixed to the pedestal 43 and extends vertically to the floor surface. The table 44 is fixed to the support column 43 so that the gamma ray detecting unit 1 (or the gamma ray detecting unit 2) can be attached and detached. The table 44 is configured to fix the gamma ray detecting unit 1 so that the long side of the gamma ray detecting unit 1 is as close as possible to the patient in order to place the patient's breast on the detection surface sufficiently. Further, the table is provided with a shielding agent such as lead so that unnecessary gamma rays do not enter from the back surface of the gamma ray detecting unit 1. The compression plate 45 is for pressing the breast placed on the gamma ray detection unit 1, and the support column 43 so as to move toward and away from the gamma ray detection unit 1.
It is fixed to.

When collecting mammo, the breast of the patient is placed on the gamma ray detecting section 1 attached to the table 44 and then compressed by the compression plate 45. By sending the data collected in this state to the waveform processing unit 13, the image display unit 2
In 3, it is possible to obtain a nuclide distribution image in the breast. It should be noted that the fact that the gamma ray detection unit 1 is used alone may be input to the input means of the image processing unit 17 as arrangement information. Further, instead of the compression plate 45, the second gamma ray detecting unit 2 is attached so that the two gamma ray detecting units face each other.
Gamma rays may be collected by one gamma ray detector.

According to the present invention as described above, the following effects can be obtained. (1) Since a semiconductor sensor is used to detect gamma rays, the gamma ray detector can be made smaller and lighter. By reducing the size of the gamma ray detector, it is possible to reduce the feeling of emotional pressure on the patient and improve the safety. Further, since the gamma ray detector is light in weight, the structure of the supporting mechanism of the gamma ray detector can be simplified. (2) Since the semiconductor sensor is used, gamma rays can be detected with high sensitivity, and the collection time can be shortened as compared with the conventional case. This makes it possible to realize whole body SPECT acquisition, which has been difficult to realize in the past due to the problem of long acquisition time. (3) Since the shield on the side of the gamma ray detection unit can be shortened, the patient position setting at the time of head SPECT acquisition becomes easy, and the proximity of the detector becomes easy. (4) Since the thickness of the gamma ray detector can be reduced, it is not necessary for the patient to raise his / her arm up during SPECT acquisition of the heart, and the burden on the patient can be reduced. (5) Since the shield on the side of the gamma ray detection unit can be shortened, mammo collection can be performed. (6) Since the length of the gamma ray detector in the body axis direction of the subject can be shortened when collecting the whole body, the gamma ray detector can be brought closer to the subject when the closest approach trajectory collection is performed, which results in The resolution is improved. (7) Since the gamma ray detector is detachably attached to the support mechanism, it is possible to support various diagnostics such as head collection, whole body collection, mammo collection, hand carry collection, etc. simply by changing the support mechanism. You can

The present invention can be implemented with various modifications, which are limited to the above-mentioned embodiments. For example, the first
It is also possible to use as a positron camera by supporting the gamma ray detecting unit 1 and the second gamma ray detecting unit 2 so that they are opposed to each other and being configured to detect the simultaneous input of gamma rays to the two gamma ray detecting units. .

[0035]

The gamma ray detector according to the present invention comprises a first gamma ray detector having a two-dimensional array structure of a plurality of semiconductor sensors for detecting gamma rays, and a plurality of semiconductor sensors for detecting gamma rays. And a second gamma ray detector having a two-dimensional array structure.

Further, the nuclear medicine diagnostic apparatus according to the present invention includes a first gamma ray detecting section having a two-dimensional array structure of a plurality of semiconductor sensors for detecting gamma rays, and a plurality of semiconductor sensors for detecting gamma rays. A second gamma ray detecting section having a two-dimensional array structure, and means for imaging the gamma ray in-vivo distribution based on the output of the first gamma ray detecting section and the output of the second gamma ray detecting section. To have.

Since the gamma ray detector has the first and second gamma ray detecting portions, it is possible to connect these two detecting portions to one sheet or in an L-shape or to face each other. It may be possible to utilize in an aspect. Therefore, various imaging objects of different sizes, plane collection, and SP
The versatility can be enhanced for various imaging methods such as ECT imaging.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a nuclear medicine diagnostic apparatus according to one embodiment of the present invention.

FIG. 2 is a diagram schematically showing the structure of a gamma ray detection unit in FIG.

3A to 3C are views showing various modes when the two gamma ray detecting units in FIG. 1 are connected in a plane.

FIG. 4 is a diagram showing a frame used when the two gamma ray detecting units in FIG. 1 are connected in a plane.

5 is a diagram showing a structure of a support mechanism for the two gamma ray detection units in FIG.

FIG. 6 is a diagram showing a structure of a support mechanism for the two gamma ray detection units in FIG.

FIG. 7 is a diagram showing two gamma ray detection units supported in an L shape by a support mechanism for 90 ° ECT imaging of the heart.

FIG. 8: Whole body or head plane collection or SPECT
FIG. 3 is a diagram showing two gamma ray detection units connected in a plane for imaging.

FIG. 9 is a diagram showing a state of SPECT imaging of the chest and abdomen.

FIG. 10 is an external view of a support mechanism for collecting mammoths.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... 1st gamma ray detection part, 2 ... 2nd gamma ray detection part, 3 ... Semiconductor sensor, 5 ... Collimator, 7 ... Preamplifier, 9 ... Analog-digital converter, 11 ... Energy spectrum collection part, 13 ... Waveform processing part, 15 ... Wave height analysis unit, 17 ... Image processing unit, 19 ... Image memory, 21 ... Image processing unit, 23 ... Image display unit.

Claims (9)

[Claims] 1. A first gamma ray detecting section of a plurality of semiconductor sensors arranged two-dimensionally for detecting gamma rays, and a second two-dimensional array structure of a plurality of semiconductor sensors for detecting gamma rays. And a gamma ray detector of the above. 2. The gamma ray detector according to claim 1, further comprising a frame for connecting and holding the first gamma ray detecting unit and the second gamma ray detecting unit. 3. The frame has shielding means for preventing the gamma rays from entering the first gamma ray detecting unit and the second gamma ray detecting unit from the side surface and the back surface. Item 2. The gamma ray detector according to item 2. 4. The gamma ray detector according to claim 1, further comprising a support mechanism that supports the first gamma ray detector and the second gamma ray detector by separate arms. 5. A first gamma ray detecting section in which a plurality of semiconductor sensors for detecting gamma rays are arranged two-dimensionally, and a second gamma ray detecting structure having a two-dimensional array structure of a plurality of semiconductor sensors for detecting gamma rays. And a means for imaging the in-vivo distribution of gamma rays based on the output of the first gamma ray detecting section and the output of the second gamma ray detecting section. apparatus. 6. A frame for connecting and holding the first gamma ray detecting unit and the second gamma ray detecting unit together, wherein the frame includes the first gamma ray detecting unit and the second gamma ray. 6. The nuclear medicine diagnostic apparatus according to claim 5, further comprising a shielding unit for preventing gamma rays from entering the detection unit from the side surface and the back surface. 7. The nuclear medicine diagnostic apparatus according to claim 5, further comprising a support mechanism that supports the first gamma ray detection unit and the second gamma ray detection unit by separate arms. 8. The image forming means comprises means for inputting the arrangement state of the detector, and an image is created based on an input to the input means. Nuclear medicine diagnostic equipment. 9. A gamma ray detecting section in which a plurality of semiconductor sensors for detecting gamma rays are two-dimensionally arranged, and a gamma ray detecting section for arranging the gamma ray detecting section at a predetermined position with respect to a subject. A nuclear medicine diagnostic apparatus, comprising: a support mechanism to which the gamma ray detection unit is detachably attached, and a means for imaging the internal distribution of gamma rays based on the output of the gamma ray detection unit.