JPH1039030A - Nuclear medicine diagnosis apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nuclear medicine diagnosis apparatus capable of enhancing degree of freedom of collection by decreasing a detector in size and weight. SOLUTION: There is disclosed a nuclear medicine diagnosis apparatus wherein gamma rays that are emitted from a radioisotope given to a subject to be inspected are detected by a detector 11 and a distribution of the radioisotope in the subject is imaged based on the output of the detector 11. In the detector 11, a plurality of semiconductor devices for directly converting gamma arrays into electric signals are two-dimensionally arrayed in a range of 15cm-30cm in a lateral direction and 20cm-50cm in a longitudinal direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nuclear medicine diagnostic apparatus for detecting gamma rays emitted from a radioisotope administered to a subject and imaging the distribution of the radioisotope in the body.

[0002]

2. Description of the Related Art A nuclear medicine diagnostic apparatus is characterized in that a single photon nuclide is used to detect one gamma ray when a radioisotope is decaying, and a two-dimensional gamma ray accumulated image is obtained based on the detected data. Using a single photon camera and emitting a pair of gamma rays in the opposite direction when the positron is annihilated using a positron nuclide,
It is classified into a boditron camera characterized in that a two-dimensional gamma ray accumulated image is obtained by specifying an emission place.

In recent years, a technique of tomographic imaging (ECT (emission computed tomography)) for detecting a gamma ray at a plurality of angles and reconstructing a tomographic image based on the gamma ray has been put to practical use. This ECT is a single photon E
CT (SPECT) and positron ECT (PET) are roughly classified.

In the conventional scintillation, a photomultiplier tube is arranged two-dimensionally and closely via a light guide on a scintillator (NaI single crystal) which gives gamma rays to light, as typified by an Anger type camera. The location of the gamma ray is calculated from each output signal by weight addition calculation. Since the photomultiplier tube is used as the photoelectric conversion element, the detector has an extremely thick oval, and the position of the outermost periphery of the photomultiplier tube cannot be calculated. A space is generated, and the detector becomes an extremely large area for the effective visual field. If a lead shield on the periphery or the back is inserted up to the collimator in ぴ, it becomes a very large detector, and even if this detector is set according to the purpose of collection, control is added to freedom and realization of operation Since the means is extremely mechanically difficult and the detector is as heavy as several hundred kg, image deterioration due to mechanical distortion may occur from ideal operation. In addition, since the distance from the end of the effective visual field to the embedded end surface of the detector is large and the detector is thick, the cardiac SPEC
At the time of T, it is necessary to raise the arm greatly to the head side, and thus there is a problem that the presenter suffers pain and the cerebellum does not enter in the head SPECT.

Conventionally, when performing SPECT of the heart, in order to avoid interference with a very large Anger-type detector, the subject must hold his or her arms on the side of the head for at least 10 minutes during the data acquisition period. It was very painful for the subject.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a nuclear medicine diagnostic apparatus capable of reducing the size and weight of a detector and thereby improving the degree of freedom of collection. It is another object of the present invention to provide a nuclear medicine diagnostic apparatus capable of performing SPECT data collection without causing significant pain to a subject during cardiac SPECT.

[0007]

According to the present invention, a gamma ray emitted from a radioisotope administered to a subject is detected by a detector, and the distribution of the radioisotope in the body is determined based on the output of the detector. In the nuclear medicine diagnostic apparatus for imaging a plurality of semiconducting elements for directly converting the gamma rays into an electric signal, the detector may have a length of 15 cm to 30 c.
It has a two-dimensionally arrayed structure within a range of 20 cm to 50 cm in the range of m.

The present invention also provides a nuclear medicine diagnostic apparatus for detecting gamma rays emitted from a radioisotope administered to a subject, and imaging the distribution of the radioisotope in the body based on the output of the detector. A plurality of semiconductor elements for directly converting the gamma rays into electric signals are provided.
a first detector two-dimensionally arrayed within a range of 30 cm to 30 cm and a width of 20 cm to 30 cm; a first support mechanism for supporting the first detector; A plurality of semiconductor elements for converting signals into vertical signals
It comprises a second detector two-dimensionally arrayed within a range of 5 cm to 30 cm and a width of 20 cm to 50 cm, and a second support mechanism for supporting the second detector.

According to the present invention, the size and weight of the detector can be reduced, so that the degree of freedom of collection can be improved. The present invention also provides a nuclear medicine diagnostic apparatus that detects gamma rays emitted from a radioisotope administered to a subject and images the distribution of the radioisotope in a body, and directly converts the gamma rays into an electric signal. A semiconductor detector in which a plurality of semiconductor elements are two-dimensionally arranged; a unit for rotating the semiconductor detector around the subject; a bed on which the subject is placed; and a support for the arm of the subject The armrest restricts the opening of the arm with respect to the body axis of the subject to at least 45 ° or more.

According to the present invention, since the semiconductor detector is smaller and thinner than the Anger-type detector, the subject is placed in a painful posture in which the arms are raised to the head side as in the prior art during cardiac SPECT. It is possible to receive data in a very comfortable posture with both arms open at 45 ° or more with respect to the body axis. In addition, since the opening is limited to 45 ° or more by the armrest, the subject does not need to maintain the open position by his / her own force.

[0011] Further, (1) since the subject is in pain, the factor that the image is degraded by moving the body can be reduced, and (2) the armrest has a structure that can be easily attached and detached. (4) Since the arm of the armrest has a U-shaped structure, the arm does not protrude from the armrest and does not interfere with the detector and the arm.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the nuclear medicine diagnostic apparatus according to the present invention will be described below with reference to the drawings. The nuclear medicine diagnostic apparatus of the present invention uses a single photon nuclide to detect one gamma ray when a radioisotope decays, and obtains a two-dimensional gamma ray accumulated image based on the detected data. Using a camera (scintillation camera) to emit a pair of gamma rays in the opposite direction when a positron annihilates using a boditron nuclide, and to obtain a two-dimensional accumulated image of gamma rays by specifying the emission location Positron camera,
Single photon ECT (SPECT), which detects gamma rays from a single photon nuclide from a plurality of angles around the subject and reconstructs a tomographic image based on the gamma rays, and gamma rays from a boditron nuclide at a plurality of angles around the subject And a positron ECT (PET) for reconstructing a tomographic image based on the detected data. Here, single photon camera (scintillation camera) and SPE
A type that can also be used for CT will be described as an example. (First Embodiment) FIG. 1 shows a block diagram of a nuclear medicine diagnostic apparatus according to the present embodiment. The detector 11 includes a collimator 13 of a parallel-porous type, a semiconductor element array 15 in which a plurality of semiconductor elements for directly converting gamma rays into electric signals are arranged vertically and horizontally, and individually amplifies the output of each of the plurality of semiconductor elements. And a preamplifier array 17.

An image generation processor 19 generates a so-called static image of the distribution of radioisotopes administered to the subject based on the output of the preamplifier array 17. At the time of SPECT acquisition, the image generation processor 19 reconstructs a radioisotope distribution in the body of the subject as a tomographic image based on the output of the preamplifier array 17. These image data are displayed on the display 21.

The stand 23 supports the detector 11. The stand traveling mechanism 25 is configured so that the stand 23 can be electrically driven according to a control signal of the movable section controller 35.
And a position detection function that can be realized by a rotary encoder or the like in order to feed back the position of the stand 23. The stand traveling mechanism 25 is configured so that the detector revolving mechanism 27 can rotate (revolve) the detector 11 around the subject in accordance with a control signal from the movable section controller 35. In order to feed back the revolution angle of the detector 11 to the controller 35, a revolution angle detection function which can be realized by a rotary encoder or the like is provided. For convenience of explanation, the detector 1
The center of rotation (revolution) of the center point of the detection surface is set as the origin, the rotation axis of the rotation is the X axis, and the radial direction of the revolution passing from the origin to the center point of the detection surface is perpendicular to the Z axis and the XZ axis. A moving coordinate system with the Y axis is defined.

The detector moving mechanism 29 is configured so as to be able to move the detector 11 in parallel with respect to each of the three XYZ orthogonal axes by a relatively small distance in accordance with the control signal of the movable unit controller 35, Further, it has a position detection function that can be realized by a rotary encoder or the like in order to feed back the position of the detector 11 with respect to each of the three XYZ orthogonal axes to the movable unit controller 35. The detector rotation mechanism 31 is configured so that the detector 11 can be electrically rotated (rotated) about a rotation axis parallel to the Z axis in accordance with a control signal of the movable section controller 35. It has a rotation angle detection function that can be realized by a rotary encoder or the like to feed back the rotation angle of the detector 11.

The couch 33 supports the subject, for example, in a supine position so that the body axis of the subject coincides with or is substantially parallel to the Z axis. The movable unit controller 35 includes a console 37
The stand traveling mechanism 25, the detector revolving mechanism 27, the detector moving mechanism 29, and the detector rotating mechanism 31 are individually controlled in accordance with the operator's instruction input via the. In addition, the movable unit controller 35 performs the whole body collection and the SPECT.
Stand traveling mechanism 25, detector revolving mechanism 27, detector moving mechanism 29, and detector rotating mechanism 31 required at the time of collection
To control the relative movement of

FIG. 2 shows the appearance of the detector 11 shown in FIG. The semiconductor element array 15 is excellent in energy resolution as compared with a conventional indirect detection method combined with a scintillator photomultiplier tube, for example, an outer dimension of 3 mm × 3 mm × 5.
mm of CdZnTe, etc.
They are two-dimensionally arranged in a rectangle of m to 30 cm and 20 to 50 cm in width. This rectangular size is determined as an optimal size in which the heart and the head enter the field of view (15 cm to 30 cm × 20 cm to 50 cm) of the detector 11 and avoids abundant use of relatively expensive semiconductor elements. Have been. Although not shown, a shield layer made of gamma ray impermeable lead or the like is formed on the side and the back of the semiconductor element array 15 and the preamplifier array 17 in order to avoid erroneous detection due to the incidence of gamma rays from the side and the back. I have.

FIG. 3A is a front view of a detector system including the detector 11, the bed 31, the stand 23, and the like, and FIG. 3B is a side view of the detector system. The stand 25 has two columns 39 and a stand base 41. The stand traveling mechanism 25 has a structure in which a recess 43 formed on the bottom surface of the stand base 41 is movably fitted to a traveling rail 45 provided on the floor surface, a traveling drive motor, and a power transmission system. The detector revolving mechanism 27 includes a structure in which a rotating ring 49 is rotatably provided on a fixed ring 47 fixed to a column 39 of the stand 25, a driving motor 51, and a driving gear provided on a driving shaft of the driving motor 51. 53 and a power transmission system including a timing belt 55 stretched over the drive gear 53 and the rotating ring 49.

The cylindrical member 57 fixed to the rotating ring 49
, A support arm 59 for supporting the detector 11 is slidably inserted, and this structure allows the detector 1 to be moved with respect to the Z axis.
1 can move, that is, the detector 11 can approach / separate from the subject (see FIG. 4B). As shown in FIG. 4A, one end of the support arm 59 is slidably and rotatably fitted into an X guide groove 61 and a Y guide groove 63 formed on the back surface of the detector 11. The detector 11 can move with respect to the axis and can rotate.

Although not shown, the electrical connection between the detector 11 and the image generation processor 19 is realized by a slip ring mechanism. Next, a static image collecting operation will be described. As described above, the detector 11 is configured with a relatively small field of view such that a head or heart can enter.
Therefore, when collecting a relatively large target portion that cannot be included in this field of view, a device for the collection procedure is required.

FIG. 5 (a) shows a procedure for collecting the chest. In this case, the intermittent movement of the detector 11 in the X or Y direction and the detector 11 are controlled by the movable controller 35.
Is performed in synchronization with the detection operation of one unit of gamma rays. Note that an operation in which the detector 11 continues to detect a gamma ray for a predetermined time and collects data necessary for image generation is defined as "" one-unit detection operation ゛ ". ), The detection is continued for a predetermined period of time. During this period, the detection of gamma rays is continued. Then, the detector 11 is moved to the position (B) and stopped for a predetermined period of time, and the detection of gamma rays is continued during this period. The acquisition procedure in which the detector 11 is moved in parallel and the detection operation of one unit is repeated twice is defined as a two-step operation.

As shown in FIG. 5B, the detector 11 can be rotated and collected according to the shape of the target portion. FIG. 6 shows a procedure of whole body collection. In the whole body collection, the detection operation of one unit is repeated in the order represented by (1) to (n), that is, in the X direction (body axis direction), the detector 11 is set to a predetermined time required for the detection operation of one unit. It moves intermittently as a cycle, and in synchronization with this, the detector 11 repeats the operation of detecting one unit of gamma rays.
Further, in a part such as the chest and the torso where the width of the subject P is longer than the field of view of the detector 11, the two-step operation shown in FIG. In addition, the two-step operation is not used in combination with the part including the head and the tip of the foot where the width of the subject P is shorter than the field of view of the detector 11. Such a procedure enables efficient whole body collection.

When collecting the closest approach trajectory, the detector 11 having a small visual field and light weight according to the present embodiment is more susceptible to light than a conventional detector having a large visual field weight in which a scintillator and a photomultiplier are combined. The specimen P can be brought closer to the subject by 25 mm or more. By designing so that the sensitivity of the collimator 13 is improved by an amount corresponding to the improvement of the resolution, it is possible to design so as to obtain a system sensitivity of about three times per unit area compared to the related art while having a small visual field. .
In addition, the energy resolution of the detector 11 using the semi-conductive element according to the present embodiment is much better than that of a conventional detector having a large field of view that combines a scintillator and a photomultiplier tube ( ^{99 m).}
For Tc, the energy resolution is about 5% in the semiconductor device with respect to the conventional energy resolution of about 10%. Therefore, the whole body image having the same count number in the same collection time as the conventional large-field detector has high contrast. Can be collected with resolution.

Next, the SPECT acquisition operation will be described. The detector 11 revolves intermittently at a fixed angle, and one unit of the detecting operation by the detector 11 is repeated in synchronization with the intermittent rotation, so that data necessary for SPECT of the subject can be collected. Similarly, in the SPECT acquisition, a device is required for the acquisition procedure.

As shown in FIG. 7, in synchronization with the intermittent revolving motion of the detector 11, the reciprocating motion of the detector 11 in the Y direction (two-step operation) is performed while the revolving motion is stopped. Thereby, the small visual field of the detector 11 can be compensated.

FIG. 8A shows the position of the detector 11 in the Y direction at the time of the first round of SPECT collection, and FIG. 8B shows the position of the detector 11 in the Y direction of the second round of SPECT collection. Is shown. In order to compensate for the small field of view of the detector 11, at least two rounds of SPECT acquisition may be performed. In this case, the positions in the Y direction are different between the first round and the second round so that the field of view of the detector 11 does not overlap between the first round and the second round. The method of FIG. 8 has a simpler operation than that of FIG. 7, and the number of times the detector 11 is moved in the Y direction is small, and the collection time can be reduced by the time required for this movement. In addition to collecting intermittent orbital movements,
It can respond to continuous orbital motion.

FIG. 9 shows a collection procedure in the case where the center of revolution and the center of the target site such as the heart are shifted. In such a case, the detector 11 is set to Y at each angle of the revolving motion so that the target portion enters the field of view at each angle of the revolving motion of the detector 11.
The position of the detector 11 is adjusted by moving an appropriate distance in the direction.

Of course, a SPECT image can be obtained without operating in the Y direction by employing a detector having an effective field of view of, for example, about 25 cm in length and 50 cm in width in the system shown in FIG. Needless to say, acquisition can also be obtained by a single scan as in the past.

The present embodiment can be modified as follows. As shown in FIGS. 10A and 10B,
The rotation ring 49 may be rotatably supported by the fall prevention driven wheel 61, and the rotation ring 49 may be directly driven to rotate by the drive gear 53.

As shown in FIG. 11, a mobile trolley 63 on which the detector system can be mounted from the stand base 41 can be moved to an examination room or an emergency medical room in a hospital. , Bogie body 65 and handle 6
7 and casters 69. The caster 69 is provided at the bottom of the bogie main body 65 so as to be vertically movable so that the caster main body 65 can be fixed to the floor surface by being lowered during movement and raised during installation.

As shown in FIGS. 12 and 13, FIG.
3 may be configured as a two-detector type nuclear medicine diagnostic apparatus provided with two systems. The first detector system 101-1 has first components 11-1 to 59-1 similar to those shown in FIGS. 1 to 3, and the second detector system 101-2 also has the same structure as that shown in FIGS. 3 has second components 11-2 to 59-2 similar to those shown in FIG. The second detector system 101-2 is inverted by 180 ° and mounted on a common running rail 45 as the first detector system 101-1.

By providing two detector systems in this way, the following collecting operation is realized. With the positional relationship between the first detector 11-1 of the first detector system 101-1 and the second detector 11-2 of the second detector system 101-2 kept at 90 °, By revolving around the subject P, a so-called 90 ° SPECT acquisition of the subject P can be performed jointly by both parties. In addition, collection at an angle other than 90 ° can be performed without any problem. In addition, the first detector 11-1 and the second detector 11-2 revolve around the subject P while maintaining the positional relationship facing the subject P with the subject P interposed therebetween, and the two detectors cooperate. Subject P (7) SPECT
By collecting, SPECT by about half a revolution
The necessary data collection can be completed.

As shown in FIG. 14, the first detector 11-1 detects a gamma ray from a first site (eg, heart) of the subject P, and the first detector 11-1 detects the gamma ray. Generating a first body distribution in the image generation processor 19 based on the output;
The second detector 11-2 detects gamma rays from a second part (for example, the head) of the subject P, and generates an image based on the output of the second detector 11-2. A distribution can be generated and thus static collection can be performed at two locations simultaneously. Similarly, SPECT acquisition can be performed at two places at the same time. Also, the first detector 11-1 and the second detector 11-1
It is also possible to collect data under different collection conditions with the detector 11-2.

As shown in FIG. 14, the armrest 63 on which the subject P places his or her arm is oriented in a direction crossing the body axis of the subject P (for example, at an angle of about 90 ° with respect to the body axis). The bed 3 so that the arm can be stably supported
3 to reduce the burden of the test rest P at the time of simultaneous collection of the heart and the head, which could not be performed conventionally. In addition, even if only heart collection is considered, in the past, since a large Anger-type detector interfered with the arm, collection was not possible without raising the arm greatly, but in a very comfortable posture Collection can be performed.

As described above, according to the present embodiment, the following effects can be obtained by using the detector having a small visual field by the semi-conductive element. (1) Since the system sensitivity of the semiconductor detector is remarkably higher than that of a conventional detector combining a scintillator and a photomultiplier, the SPECT collection time of the heart and the head can be reduced to half or less of the conventional one, and Good energy resolution,
The contrast ratio of the image is high because the mixing ratio of the scattered radiation in the window of interest is small. (2) A collection that was possible in the past, such as a whole body SPECT, a whole body collection, or a static collection, can be performed in the same or longer collection time,
Moreover, the contrast resolution of the image is high. (3) When two detector systems are considered, it is possible to simultaneously collect SPECT or statistic at two different locations in the body axis direction such as the heart and the head, which was not possible in the past. Can be collected at (4) 90 SPECT of the heart can be collected easily and in less than half the time. (5) Upgrade from one detector system to two detector system can be easily realized. (6) 1 from the effective visual field edge to the shield edge of the semiconductor detector
Because it is shorter than cm, it is possible to do mammoscinching while sitting on a desk. (7) The mobile trolley can be moved to another inspection room. (8) The transmission CT can be easily realized with high image quality using the two-detector system. (9) The opening diameter of the entire rotating ring can be designed to be large, and there is no intimidation as a whole, so that the subject has a great sense of security. (10) Since the weight of the collimator can be reduced to around 10 to 20 kg, it can be mounted by hand. (11) In a two-system detector system, the count processing capability of the semiconductor detector is excellent at 500 kcps or more. F
It can also be used for detection of DG-PET coin denseness. (Second Embodiment) FIG. 15 shows a configuration of a main part of a nuclear medicine diagnostic apparatus according to a second embodiment. The configuration of the nuclear medicine diagnostic apparatus according to the second embodiment differs from the first embodiment in the following points. The nuclear medicine diagnostic apparatus according to the second embodiment does not employ an Anger type detector, and is smaller, thinner and lighter than the Anger type detector.
However, a configuration is employed in which the object P is supported from the stand 133 via the arms 1391 and 1392 with the subject P interposed therebetween. Such semiconductor detectors 1221, 122
2, the subject P required for cardiac imaging using the Anger-type detector does not need to take a burdensome posture in which both arms are greatly raised to the head side. ), A relatively comfortable posture with both arms open at an angle θ of 45 ° or more, and at most 90 °.

In order to further facilitate this posture, an armrest 140 is used. The armrest 140 is configured so that the subject P can restrict the opening angle θ between each of the arms and the body axis to a specific angle of at least 45 ° or more. It is molded. The armrest 140 is mounted so as not to move to an arbitrary position on the top plate 137 and can be removed from the top plate 37 when not in use.
A magic fastener 141 is provided at a central portion of 40.

Arm rest portion 142 of arm rest 140
Is formed in a substantially U-shaped cross section (or a substantially U-shaped cross section or a substantially L-shaped cross section) with an open top, and the arm rests on the armrest 1.
The arm prevents the arm from being displaced, moving, or closing the arm, and in particular, the arm 122 and the detector 12 are used during SPECT imaging in which the detectors 122 1 and 122 2 rotate around the subject P.
21 and 1222 can be reliably prevented.

Conventionally, when the thickness of the Anger-type detector and the distance from the end of the effective visual field to the outer end surface of the shield (dead space) are as large as 5 cm or more, both arms are raised greatly toward the head, and the Anger-type detector is used. It was necessary to make the head side as close as possible, but the semiconductor detectors 122 1,
The 1222 can be designed to be very thin and can be designed to have a thickness of about 5 cm to 10 cm including the collimator portion. Further, since the position can be detected by each semiconductor element as it is, the two-dimensional shape of the semiconductor element can be obtained. All of the surfaces arranged in the vertical direction can be used as an effective visual field, and the distance from the effective visual field edge to the outer edge of the shield is substantially almost equal to about 5 mm in the shield thickness.
The size can be drastically reduced to about 15 mm to 15 mm, so that the above-described posture can be achieved.

As described above, the armrest 1 of the present embodiment
By using 40 in combination with the semiconductor detectors 122 1 and 122 2, the pain of the subject P is greatly reduced, and the possibility that the image of the subject P moves during the collection period is less likely to deteriorate. Become.

As shown in FIG. 16, this armrest may be structured such that the rest bodies 1441 and 1442 on which the arms are placed are supported by the stands 1431 and 1432 instead of being mounted on the top plate. The present invention is not limited to the embodiments described above, and can be implemented with various modifications.

[0041]

According to the present invention, the size and weight of the detector can be reduced, and the degree of freedom of collection can be improved. Also,
According to the present invention, since the semiconductor detector is smaller and thinner than the Anger-type detector, it is necessary for the subject to take a painful posture in which the both arms are raised to the head side as in the related art during cardiac SPECT. And data can be collected in a very comfortable posture with both arms open at 45 ° or more with respect to the body axis. In addition, since the opening is limited to 45 ° or more by the armrest, the subject does not need to maintain the open position by his / her own force.

(1) Since the subject is in pain, the factor that the image is degraded by moving the body can be reduced. (2) The armrest has a structure that can be easily attached and detached. (4) Since the arm of the armrest has a U-shaped structure, the arm does not protrude from the armrest and does not interfere with the detector and the arm.

[Brief description of the drawings]

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

FIG. 2 is an external view of the detector of FIG.

FIG. 3 is a front view and a side view of the detector system according to the embodiment.

FIG. 4 is a view showing a detector moving mechanism of FIG. 1;

FIG. 5 is an explanatory diagram of a procedure for collecting a chest, a head, and a heart according to the embodiment.

FIG. 6 is an explanatory diagram of a whole-body collection procedure according to the present embodiment.

FIG. 7 is an explanatory diagram of a SPECT acquisition procedure according to the embodiment;

FIG. 8 is an explanatory diagram of another SPECT acquisition procedure according to the embodiment.

FIG. 9 is an explanatory diagram of a SPECT acquisition procedure when the center of revolution and the center of a target site such as a heart are shifted according to the embodiment;

FIG. 10 is a diagram showing another configuration example of the detector revolution mechanism of FIG. 1;

FIG. 11 shows a mobile trolley for moving the detector system.

FIG. 12 is a block diagram of a nuclear medicine diagnostic apparatus having two detector systems as a modified row of the embodiment.

FIG. 13 is a side view of the system of FIG.

FIG. 14 is a view showing a state of simultaneous collection at two places by the system of FIG. 12;

FIG. 15 is a view showing an armrest according to a second embodiment.

FIG. 16 is a diagram showing a modification of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Detector, 13 ... Collimator, 15 ... Semiconductor element array, 17 ... Preamplifier array, 19 ... Image generation processor, 21 ... Display, 23 ... Stand, 25 ... Stand traveling machine ellipse, 27 ... Detector revolving mechanism, 29 ... Detector moving mechanism, 31: detector rotation mechanism, 33: bed, 35: movable section controller, 37: console.

Claims (22)

[Claims] 1. A nuclear medicine diagnostic apparatus for detecting gamma rays emitted from a radioisotope administered during a test period with a detector, and imaging an internal distribution of the radioisotope based on an output of the detector. In the above, the detector may have a structure in which a plurality of semiconductor elements for directly converting the gamma rays into electric signals are two-dimensionally arrayed within a range of 15 cm to 30 cm in length and 20 cm to 50 cm in width. A nuclear medicine diagnostic device characterized by the above-mentioned. 2. The nuclear medicine diagnostic apparatus according to claim 1, wherein the semiconductor element is CdZnTe. 3. A mechanism for revolving the detector around the subject, a mechanism for individually moving the detector in each of a longitudinal direction, a lateral direction, and a radial direction of the revolution, and the radial direction. A rotation mechanism for rotating the detector with respect to an axis parallel to the axis, and means for relatively moving the subject and the detector along a body axis direction of the subject. Item 6. A nuclear medicine diagnostic apparatus according to Item 1. 4. The method according to claim 1, wherein the movement along the body axis direction and the movement in the lateral direction are performed in synchronization with each other, and the gamma ray detection operation is performed intermittently in synchronization with the movement. The nuclear medicine diagnostic apparatus according to claim 3, wherein the whole body is collected. 5. The nuclear medicine diagnostic apparatus according to claim 4, wherein the specific position of the subject involves movement of the detector in one of the vertical direction and the horizontal direction. 6. In a portion including a head and a foot tip portion of the subject whose width is shorter than the field of view of the horizontal protruding device, the detector does not move in one of the vertical direction and the horizontal direction, The nuclear medicine diagnostic apparatus according to claim 5, wherein the other portion whose width is longer than the field of view of the detector involves movement of the detector in one of the vertical direction and the horizontal direction. 7. Synchronizing a reciprocating motion of the detector in one of the vertical direction and the horizontal direction, an intermittent revolving motion of the detector, and an operation of detecting one unit of the gamma ray by the detector. By doing so, the SPE of the subject
The nuclear medicine diagnostic apparatus according to claim 3, wherein data necessary for CT is collected. 8. The SPEC of the subject is performed by synchronizing the orbital motion of at least two rounds of the detector with the detection operation of one unit of the gamma ray by the detector.
Collect the data necessary for T, and perform the first and second
The nuclear medicine diagnostic apparatus according to claim 3, wherein the position of the detector with respect to one of the vertical direction and the horizontal direction is different in a circumference. 9. Cardiac SPECT acquisition and head SPECT
4. The nuclear medicine diagnostic apparatus according to claim 3, wherein the angle of rotation of the detector differs by 90 degrees between the time of acquisition and the time of acquisition. 10. An intermittent orbiting motion of the detector and a detection operation of one unit of the gamma ray by the detector when the center of the orbit is deviated from the center of a collection target part in the subject. Is performed in synchronization with each other, data necessary for SPECT of the collection target site is collected, and the revolving motion of the revolving motion is included such that the collection target site is included in the field of view of the detector at each angle of the revolving motion. The nuclear medicine diagnostic apparatus according to claim 3, wherein a position of the detector with respect to one of the vertical direction and the horizontal direction is adjusted at each angle. 11. A bed provided with an armrest on which the subject places an arm, wherein the armrest can stably support the arm in a direction crossing the body axis of the subject. The nuclear medicine diagnostic apparatus according to claim 1, wherein: 12. The nuclear medicine diagnostic apparatus according to claim 1, further comprising a stand for supporting the detector, and a carriage for mounting the stand. 13. A nuclear medicine diagnostic apparatus for detecting a gamma ray emitted from a radioisotope administered to a subject, and imaging a distribution of the radioisotope based on an output of the detector. A plurality of semiconductor elements for directly converting gamma rays into electric signals have a length of 15 cm to 30 cm and a width of 20 cm.
a first detector that is two-dimensionally arrayed within a range of 50 cm to 50 cm; a first support mechanism that supports the first detector; and a plurality of devices for directly converting the gamma rays into an electric signal. The semiconductor element is in the range of 15 cm to 30 cm in length and 20 in width.
A nuclear medicine diagnostic apparatus comprising: a second detector two-dimensionally arrayed within a range of 50 cm to 50 cm; and a second support mechanism for supporting the second detector. 14. The nuclear medicine diagnostic apparatus according to claim 13, wherein the semiconductor element is CdZnTe. 15. The first support mechanism and the second support mechanism, respectively, a mechanism for revolving the corresponding detector around the test rest, and a mechanism for vertically and horizontally moving the corresponding detector. A mechanism for individually moving in each of the directions and radial directions of the revolution, and a mechanism for rotating the corresponding detector about an axis passing through the center of the corresponding detector and parallel to the radial direction. 14. The nuclear medicine diagnostic apparatus according to claim 13, wherein: 16. The nuclear medicine diagnostic apparatus according to claim 15, wherein the first detector and the second detector collectively perform 90 ° SPECT acquisition of the subject. 17. The first detector and the second detector cooperate with each other in a state where the first detector and the second detector face each other across the subject. Subject SP
The nuclear medicine diagnostic apparatus according to claim 15, wherein ECT collection is performed. 18. The method according to claim 18, wherein the first detector detects a first
Detecting a gamma ray from a part of the subject, generating a first body distribution based on an output of the first detector, and detecting a gamma ray from the second part of the subject with the second detector. The nuclear medicine diagnostic apparatus according to claim 15, wherein the second body distribution is generated based on an output of the second detector. 19. The method according to claim 19, wherein the first detector detects the first
16. The nuclear medicine diagnostic apparatus according to claim 15, wherein SPECT collection is performed on a portion of the subject, and SPECT collection of a second portion of the subject is performed by the second detector. 20. A nuclear medicine diagnostic apparatus for detecting a gamma ray emitted from a radioisotope administered to a subject and imaging an internal distribution of the radioisotope, wherein the plurality of gamma rays are directly converted into an electric signal. A semiconductor detector in which the semiconductor elements are arranged two-dimensionally, means for rotating the semiconductor detector around the subject, a bed on which the subject is placed, and a support for the arm of the subject An armrest for limiting the opening of the arm relative to the body axis of the subject to at least 45 ° or more. 21. The nuclear medicine diagnostic apparatus according to claim 20, wherein the armrest is detachable from the bed. 22. The nucleus according to claim 20, wherein the armrest has a substantially U-shaped cross section to prevent the arm from falling and from contacting the semiconductor detector. Medical diagnostic device.