JPH09311187A - Nuclear medicine diagnostic imaging system - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: It is possible to display a radioactive substance distribution image of a subject at the same size as the subject at a full scale, and a display device for displaying the subject and its radioactive substance concentration distribution is in the same field of view. (EN) Provided is a nuclear medicine image diagnostic apparatus which can be easily inserted and aligned. Radiation incident from a collimator 13 provided on the back surface of the apparatus main body 3 is detected by a semiconductor detector 15, and the incident position is calculated and sequentially stored by a processor 17 and provided on the front surface of the apparatus main body 3. It is displayed on the liquid crystal display panel 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nuclear medicine image diagnostic apparatus for measuring and displaying a spatial distribution of radiation, and in particular,
Integrating a collimator, radiation detector and display device,
The present invention relates to a nuclear medicine image diagnostic apparatus in which operability is improved by directly associating a radiation diagnostic region of a subject with a diagnostic image thereof.

[0002]

2. Description of the Related Art Generally, clinical diagnosis includes morphological diagnosis and functional diagnosis. What is important in clinical diagnosis is whether or not the tissue or organ is functioning normally due to disease. With the exception of congenital abnormalities and trauma, in many diseases, anatomical morphological changes in tissues occur as functional abnormalities progress. The X-ray diagnostic apparatus and the X-ray CT apparatus are devices for this morphological diagnosis, and therefore, it is difficult to detect a functional abnormality before the morphological change at an early stage.

An X-ray diagnostic apparatus and an X-ray CT apparatus irradiate X-rays from outside the body to directly image the difference in X-ray transmittance due to tissues or organs on a film or tomographic image from the value measured by a detector. Is to be reconstructed.

On the other hand, the radioisotope (hereinafter abbreviated as RI) or a labeled compound thereof is utilized by utilizing the property of being selectively taken up by a specific tissue or organ in the living body.
There is a method of diagnosing γ-rays emitted from outside the body and imaging the dose distribution of RI to make a diagnosis, which is called a nuclear medicine image diagnostic method.

In the nuclear medicine image diagnostic method, the principle itself that a labeling substance is accumulated in a specific tissue or organ is associated with the physiological function and biochemical substance metabolism function of the tissue or organ. In addition to physical diagnosis, functional diagnosis of lesion at an early stage is possible, which is a major feature that other diagnostic methods do not have.

In this nuclear medicine image diagnostic method, a scintigram that obtains a two-dimensional distribution image using a scintillation scanner or a gamma camera device and information obtained by rotating the gamma camera around the subject are reconstructed. There is SPECT for obtaining a tomographic image of RI concentration distribution.

As an example of the conventional nuclear medicine image diagnostic apparatus, the internal structure of the detector of the gamma camera apparatus is shown in FIG. 5, and the overall structure of the gamma camera apparatus is shown in FIG.

As shown in FIG. 5, a detector 121 of a conventional gamma camera device has a lead collimator 101 provided with a plurality of honeycomb-like parallel holes 101a perpendicular to a radiation incident surface and a rear surface thereof. Arranged sodium iodide (N
aI) or the like, a scintillator 103 (phosphor), a light guide 105 for guiding the light emitted by the scintillator 103 by radiation particles, and a plurality of photomultiplier tubes 107 for detecting the light guided by the light guide 105. , A position calculation circuit 109 for calculating the light emission position of the scintillator 103 from the output of each photomultiplier tube 107, and a radiation shield 11 for shielding these devices from diffracted radiation and reflected radiation.
The spatial distribution of the gamma ray emitting nuclide (RI) which is composed of No. 1 and is distributed in the subject 113 has been measured.

Further, according to FIG. 6, the conventional gamma camera device includes a camera arm 123 supporting a detector 121,
A gantry 125 that rotatably supports the camera arm 123 around the subject, a persistence monitor 127 provided above the gantry 125, a position and posture of the detector 121, or a bed 129 on which the subject 113 is placed. And a hand controller 131 for controlling the position of.

[0010]

However, in the above-mentioned conventional gamma camera device, the radiation incident information collected by the detector is displayed as a radiation distribution image in order to align the subject and the detector. Since the cyst monitor was placed above the gantry, the orientation on the subject did not match the orientation on the display screen of the persist monitor, and the display magnification was not the same size. There was a problem that it was difficult.

In view of the above problems, it is an object of the present invention to provide a nuclear medicine image diagnostic apparatus capable of displaying a radioactive substance distribution image of a subject at the same size as the subject at a full scale.

Another object of the present invention is to provide a nuclear medicine image diagnostic apparatus which can be easily aligned with a subject.

[0013]

In order to solve the above problems, the present invention has the following arrangement. That is, the invention according to claim 1 is a radiation detector for detecting γ-rays emitted from a radioactive isotope in a subject, and a distribution image of the radioactive isotope in the subject based on the output of the radiation detector. The nuclear medicine image diagnostic apparatus is characterized in that it comprises an image processing means to be obtained and a display means provided on the back surface of the radiation detector and displaying an image based on the output of the image processing means.

According to the first aspect of the present invention, by providing the display device on the back surface of the radiation detector, the spatial distribution image of the radioactive substance in the subject can be seen through the same as the subject. The position can be observed.

With the above structure, the subject, the detector,
Since the display device can be in the same field of view, when the detector is aligned while looking at the display screen, the subject is also in the field of view, so contact between the detector and the subject can be avoided.

According to a second aspect of the present invention, in the nuclear medicine image diagnostic apparatus according to the first aspect, the radiation detector is provided with a parallel hole collimator on its front surface, and a distribution image of the radioactive isotope in the subject is obtained. Is displayed on the display device at an equal magnification.

According to the invention described in claim 2, in the invention described in claim 1, by using a parallel hole collimator, an image obtained by projecting a radioactive substance concentration distribution in a subject on a plane is displayed at an equal magnification. Can be displayed on.

According to a third aspect of the present invention, in the nuclear medicine image diagnostic apparatus according to the first or second aspect, the display position of the radiation incident on the radiation detector is substantially extended in the incident direction of the radiation. The gist is that it is the display position of the display device above.

According to the invention of claim 3, in the invention of claim 1 or 2, the position of the radiation is displayed substantially on the extension of the incident direction of the radiation incident on the radiation detector. The display image and the radioactive substance distribution of the subject can be more easily understood by the observer.

According to a fourth aspect of the present invention, in the nuclear medicine image diagnostic apparatus according to any one of the first to third aspects, the display device is a liquid crystal display panel or a plasma display panel. Use as a summary.

According to the invention described in claim 4, in the invention described in any one of claims 1 to 3, a liquid crystal display panel or a plasma display panel is used as a display device, so that a nuclear medicine image diagnostic apparatus can be further improved. It can be made thinner and the operability can be improved.

A fifth aspect of the present invention is characterized in that in the nuclear medicine image diagnostic apparatus according to any one of the first to fourth aspects, the radiation detector is a semiconductor detector. .

According to the invention of claim 5, in the invention of any one of claims 1 to 4, by using a semiconductor detector as the radiation detector, the nuclear medicine image diagnostic apparatus can be made thinner. Further, the operability can be improved.

[0024]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a perspective view showing the external appearance of a first embodiment of a nuclear medicine image diagnostic apparatus according to the present invention.

According to FIG. 1, the nuclear medicine image diagnostic apparatus 1 comprises:
The apparatus main body 3 has a substantially thin rectangular parallelepiped outer shape, and a pedestal 5 on which the apparatus main body 3 is mounted. A liquid crystal display panel 11 as a display device is provided on the upper surface of the device body 3.
Further, bolts 51 are embedded in the central portions of both side surfaces of the apparatus main body 3 which face each other, and these bolts 51 are provided at opposing positions of a U-shaped frame 61 on an upper portion of the pedestal 5. It is swingably inserted into the hole and is fixed by a wing nut 53 screwed from the outer surface of the frame.

Further, a supporting column 69 including an outer cylinder 65 and an inner cylinder 67 is hung from each angle portion 63 of the frame 61, and a right angle is formed at a lower end portion of the inner cylinder 67 which is a lower end portion of each supporting column 69. It is connected via a joint 71 to one end of each of the horizontally arranged cylindrical members 73. The cylindrical members 73 are connected at positions facing each other by a plate member 75, and casters 77 are provided at both ends of the plate member 75 to facilitate movement of the nuclear medicine image diagnostic apparatus 1.

FIG. 2 is a sectional view showing the internal structure of the apparatus body 3 of the nuclear medicine image diagnostic apparatus 1. As shown in FIG.
A liquid crystal display panel 11, a collimator 13 on the back surface, and a semiconductor detector 15 inside the liquid crystal display panel 11 are provided on the front surface of the apparatus main body 3 which is a thin and substantially rectangular parallelepiped. Further, a processor 17 is provided between the semiconductor detector 15 and the liquid crystal display panel 11.

The collimator 13 is made of a radiation shielding material such as lead, and a plurality of holes 13b having the same diameter are provided at equal intervals perpendicularly to the radiation incident surface 13a, which is the lower surface, to form a parallel collimator. are doing.

The diameter of the hole 13b of the collimator 13 is not particularly limited, but may be, for example, 1 mm to 5 mm. Similarly, the thickness of the collimator wall is 0.1 mm.
It can be ~ 2 mm.

On the upper surface of the collimator 13, silicon (S
i), a semiconductor detector 15 using a semiconductor such as cadmium telluride (CdTe) is provided to detect radiation (γ-ray) incident on the collimator 13 from a direction substantially perpendicular to the plane of incidence. . The semiconductor detector 15 is, for example, one in which square semiconductor detector devices each having a side of 10 mm are densely arranged, and the ionizing action of the radiation incident on each semiconductor detector device is extracted as a detection signal to the outside. , Pn junction type, heterojunction type and the like can be used.

The radiation incident position of the detection signal extracted from the semiconductor detector 15 is calculated by the processor 17, stored in the image memory inside the processor 17, and displayed on the liquid crystal display panel 11.

Here, the radiation incident surface 1 of the collimator 13
3a and the display surface of the liquid crystal display panel 11 are selected to be the same size, and the display position on the liquid crystal display panel 11 corresponding to the incident position of a certain radiation is made to match except for the position in the thickness direction of the device, Images of the same size as the distribution of radioactive substances in the subject can be displayed with their positions aligned. As a result, it is possible to see through the nuclear medicine image diagnostic apparatus, an image as if through the radioactive substance distribution in the subject.

Next, a second embodiment of the nuclear medicine image diagnostic apparatus according to the present invention will be described with reference to FIG. In the nuclear medicine image diagnostic apparatus of the second embodiment, the apparatus body 3 is provided at the tip of the free arm 7 supported by the gantry 5 so that it can be freely moved in the three-dimensional space. ing. That is, the pedestal 5 is vertically held on the floor surface of the installation place by the legs arranged in four directions in the horizontal direction. At the upper end of the gantry 5, the first arm 7a
One end of the first arm 7a is rotatably supported in a horizontal plane, and the other end of the first arm 7a has a small end, and the second end of the second arm 7b rotates in the horizontal plane. It is movably mounted.

The second arm 7b has a substantially L-shape, and is provided at a horizontal portion extending horizontally from the large end thereof, a vertical portion rising vertically from the tip of the horizontal portion, and a tip portion of the vertical portion. It consists of a small end. Then, a horizontal portion of a substantially inverted L-shaped third arm 7c is rotatably attached in a horizontal plane to the small end portion of the second arm 7b, and a vertical portion of the vertical portion of the third arm 7c is in a vertical plane. The upper end of the rotatable fourth arm 7d is attached to the lower end of the fourth arm 7d, and the device body 3 is attached to the lower end of the fourth arm 7d so as to be rotatable forward and backward and left and right.

The present embodiment considers the use for imaging the radioactive substance concentration distribution of the inside of the subject during laparotomy. Therefore, as compared with the first embodiment, the device body 3
Is miniaturized, and for example, has a size of about 8 cm on each side.

The internal structure of the device main body 3 is almost the same as that of the first embodiment. The liquid crystal display panel 11 is on the front surface of the device main body 3 which is a substantially rectangular parallelepiped, and the collimator 1 is on the back surface.
3, semiconductor detectors 15 are provided in the inside. It should be noted that the same reference numerals are given to the constituent elements having the same functions as those in the first embodiment, and the duplicated description will be omitted.

Further, in the present embodiment, the processor 17 may be provided outside the apparatus main body 3 due to mounting restrictions or the like.

FIG. 4 shows a state in which the radioactive substance concentration distribution of the organ (liver) 117 during laparotomy is observed by the nuclear medicine image diagnostic apparatus according to the second embodiment.
119a indicates a high concentration range and 119b indicates a low concentration range.

For example, the nuclear medicine image diagnostic method is particularly effective for the diagnosis of liver cancer and the determination of the excision range by surgery. This diagnosis utilizes the fact that a monoclonal antibody labeled with a radioactive substance is previously administered to a subject and that the antibody selectively aggregates around cancer cells. When the concentration distribution of the labeled radioactive substance is observed during the operation by the nuclear medicine image diagnostic apparatus of the present embodiment, the concentration distribution of this antibody is observed, and the portion composed of normal cells and the cancerous portion are clarified. Therefore, these positional relationships are displayed as images at the same position as the subject at the same magnification.

Although the preferred embodiment has been described above, this does not limit the present invention. For example, a collimator in which the holes of the collimator are hexagonal and arranged in a hexagonal close-packed manner may be adopted.

Further, as the display device, a plasma display panel may be used in addition to the liquid crystal display panel used in the embodiment.

[0042]

As described above, according to the present invention,
There is an effect that the radioactive substance distribution image of the subject can be displayed at the same position as the subject in a full scale.

Further, according to the present invention, the display device for displaying the object and its radioactive substance concentration distribution are in the same field of view,
There is an effect that it is possible to provide a nuclear medicine image diagnostic apparatus that can be easily aligned.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a nuclear medicine diagnostic device according to the present invention.

FIG. 2 is a cross-sectional view showing the internal structure of the apparatus main body according to the first embodiment.

FIG. 3 is a perspective view and a cross-sectional view of a main part showing a second embodiment of the nuclear medicine diagnostic apparatus according to the present invention.

FIG. 4 is a plan view illustrating a usage situation of the second embodiment.

FIG. 5 is a cross-sectional view showing an internal structure of a detector of a conventional gamma camera device.

FIG. 6 is a perspective view showing an appearance of a conventional gamma camera device.

[Explanation of symbols]

1 ... Nuclear medicine image diagnostic device, 3 ... Device body, 5 ... Stand, 1
1 ... Liquid crystal display panel, 13 ... Collimator, 15
... Semiconductor detector, 17 ... Processor.

Claims (5)

[Claims] 1. A radiation detector for detecting γ-rays emitted from a radioisotope in a subject, and image processing means for obtaining a distribution image of the radioisotope in the subject based on the output of the radiation detector. And a display means provided on the back surface of the radiation detector for displaying an image based on the output of the image processing means. 2. The radiation detector is provided with a parallel hole collimator on the front surface thereof, and a distribution image of the radioisotope in the subject is displayed on the display device at an equal magnification. 1. The nuclear medicine image diagnostic apparatus according to 1. 3. The display position of the radiation incident on the radiation detector is a display position of the display device which is substantially on the extension of the incident direction of the radiation. Nuclear medicine diagnostic imaging device. 4. The nuclear medicine image diagnostic apparatus according to claim 1, wherein the display device is a liquid crystal display panel or a plasma display panel. 5. The nuclear medicine image diagnostic apparatus according to claim 1, wherein the radiation detector is a semiconductor detector.