JPH07294650A - Gamma camera device - Google Patents

Abstract

PURPOSE:To provide a gamma camera device for obtaining an accurate position of an RI(Radio Isotope) distribution image at a specimen without using a marker ray source. CONSTITUTION:A gamma camera 7 and an X-ray detector 9b are mounted to a support frame 11b with a specific space. The support frame 11b is provided at a gantry 5 which can travel horizontally by a drive part 13a. While a shooting center CA of the gamma camera 7 is located near the concerned part of a specimen M, an RI distribution image is picked up and is stored at an RI image memory 23. The position on the subject M of the shooting center CA at this time is set to a position O and further the gantry 5 is moved by a specific space (d) to match a shooting center CB of an X-ray detector 9b to the position O of the subject M. An X-ray fluoroscopy image is picked up in this state and the X-ray fluoroscopy image is stored at an X-ray image memory 24. An image synthesis part 25 synthesizes and displays the image so that the center parts of the images stored at the memories 23 and 24 coincide with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gamma camera device which administers a radioisotope RI (radioisotope) into a subject and picks up an RI distribution from γ-ray data emitted from the RI. The present invention relates to a gamma camera device capable of obtaining the position of an image on a subject.

[0002]

2. Description of the Related Art Diagnosis using a conventional gamma camera device of this type is performed as follows. First, a mixture of a substance having a property of accumulating in an organ or the like of a region of interest and RI is injected into blood of a subject. Then, on the body surface of the subject and in the vicinity of the region of interest, a marker radiation source that emits γ-rays having lower energy than RI injected into the subject is attached. In this state, the gamma camera simultaneously detects the incident positions and intensities of the γ-rays generated from the marker radiation source and the γ-rays generated from the organ of the region of interest, and obtains the grayscale difference between them as an RI distribution image. R thus obtained
The organ position in the subject can be obtained from the relative position of the marker radiation source and the organ on the I distribution image. From this organ position, for example, when an abnormality is found in the organ from the RI distribution image, it is possible to determine which position of the subject should be incised by the operator.

[0003]

However, such a conventional device has the following problems. That is, the γ rays emitted from the marker radiation source and the R injected into the subject
The γ-ray from I interferes with each other, and a deviation occurs between the image of the organ of the subject and the position of the marker radiation source on the subject and the position of the marker radiation source on the RI distribution image. Therefore, there is a problem that an accurate position of the RI distribution image on the subject cannot be obtained based on the position of the marker radiation source on the RI distribution image. Further, since the marker radiation source emits radiation, it is necessary to obtain permission to use the marker radiation source, and therefore, there is a complicated procedure that a procedure is required to use the gamma camera device.

The present invention has been made in view of the above-mentioned circumstances, and it is possible to realize the R without using a marker radiation source.
An object of the present invention is to provide a gamma camera device capable of obtaining an accurate position of an I distribution image on a subject.

[0005]

The present invention has the following constitution in order to achieve such an object. That is, the gamma camera device according to the present invention is a gamma camera device that detects a gamma ray generated from a radioisotope administered to a subject with a gamma camera to obtain a radioisotope distribution image (RI distribution image), An examination table on which the subject lies down, an image pickup means for picking up an image of a region of interest including the contour of the body surface of the subject, and the gamma camera which holds the image pickup centers of the gamma camera and the image pickup means at predetermined intervals. The support means and the examination table are arranged at the predetermined interval so that the support means for supporting the image pickup means and the imaging centers of the gamma camera and the image pickup means coincide with each other on the region of interest of the subject. The movement control means for relatively moving the corresponding distance, the RI distribution image storage means for storing the RI distribution image obtained by the gamma camera, and the imaging means. Image storing means for storing the obtained image, image synthesizing means for synthesizing the RI distribution images stored in both of the storing means so that the centers of the images match, and synthesizing by the image synthesizing means. And a display unit for displaying an image.

[0006]

The operation of the present invention is as follows. When the gamma camera captures an image of the region of interest in the subject, RI
The distribution image is stored in the RI distribution image storage means. Since the gamma camera and the image pickup means are supported by the support means in a state where their respective imaging centers are held at a predetermined interval, when the examination table and the support means are relatively moved by the movement control means by a distance corresponding to the predetermined interval. The image capturing center of the image capturing unit coincides with the image capturing center of the gamma camera in the region of interest of the subject. The image of the region of interest including the contour of the body surface of the subject obtained by the imaging unit is stored in the image storage unit. The image synthesizing means synthesizes the RI distribution images stored in both of the storing means so that the central portions of the images coincide with each other, and displays the synthesized image on the display means. As described above, the RI distribution image and the image captured in a state where the imaging centers on the region of interest of the subject coincide with each other are combined so that the central portions coincide with each other. The positional relationship is accurately displayed on the display means.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing a schematic configuration of a gamma camera device and a block diagram of an image processing unit, and FIG.
It is a side view which shows the schematic structure seen from the body axis direction.

In the figure, reference numeral 1 is an examination table whose position is fixed. The examination table 1 is composed of a support base 1a installed on the floor and capable of expanding and contracting in the vertical direction, and a top plate 1b mounted on the upper end of the support base 1a so as to be horizontally slidable. The top plate 1b is made of an X-ray transmissive material (for example, foamed acrylic), and the subject M lies on the upper surface of the top plate 1b.

A pair of rails 3 are provided on the floor surface along the longitudinal direction (body axis direction) of the top plate 1b. A gantry 5 is movably arranged above the rail 3. The gantry 5 includes a gamma camera 7 for detecting the incident position and intensity of γ-rays from the subject M, and an X-ray fluoroscopic image capturing unit 9 for capturing an X-ray fluoroscopic image of the subject M. There is. The X-ray fluoroscopic imaging unit 9 includes the support frame 1
X-ray tube 9a attached to 1a and emitting X-rays from below the subject M, and X-rays arranged at positions facing the X-ray tube 9a for detecting X-rays transmitted through the subject M. It is composed of a detector 9b. The X-ray detector 9b is provided with a support frame 11 along the gamma camera 7 and the body axis direction.
It is arranged in the gantry 5 via b. Further, the gamma camera 7 and the X-ray detector 9b are attached to the support frame 11b such that the distances between the imaging centers C _A and C _{B in} the body axis direction are the predetermined distance d, and the gamma camera 7 and the X-ray detector 9b are attached to the body axis. The respective imaging centers C _A and C _B in the orthogonal directions are attached to the support frame 11a so as to coincide with each other. The X-ray fluoroscopic image capturing section 9 corresponds to the image pickup means in this invention, and the support frame 11b corresponds to the support means.

The gantry 5 has a plurality of wheels 13 at the bottom thereof, and is moved along the body axis direction on the rails 3 by a drive unit 13a including a motor for driving the wheels 13.

The signal corresponding to the incident position and intensity of the γ-ray from the subject M detected by the gamma camera 7 and the signal corresponding to the transmitted X-ray detected by the X-ray detector 9b are
It is input to the image processing unit 20. The functions of the image processing unit 20 are roughly classified into a movement control unit 21, an A / D conversion unit 22,
It is divided into an RI image memory 23, an X-ray image memory 24, and an image synthesizing unit 25.

The movement control unit 21 controls the drive unit 13a to move the gantry 5 along the body axis by a distance corresponding to a predetermined distance d. Further, the movement control unit 21 has a function of obtaining rotation information from the drive unit 13a, obtaining the position of the gantry 5 along the body axis direction, and moving the gantry 5 to a predetermined position. The movement control unit 21 moves the gantry 5 by a predetermined interval d after imaging with the gamma camera 7, so that the imaging center of the X-ray detector 9b is aligned with the imaging center of the subject M of the gamma camera 7. It has a function to move it to a position. This movement control unit 21
This corresponds to the movement control means in this invention.

The A / D converter 22 converts the image signal input from the X-ray detector 9b and the gamma camera 7 into a digital signal. Further, when a signal is input from the gamma camera 7, the converted signal (RI distribution image) is stored in the RI image memory 23, and when a signal is input from the X-ray detector 9b, the converted signal ( X-ray fluoroscopic image)
Are stored in the X-ray image memory 24. Image synthesizer 25
Outputs the combined RI distribution image stored in the RI image memory 23 and the X-ray fluoroscopic image stored in the X-ray image memory 24. The synthesis is performed so that the center portions of the RI distribution image and the X-ray fluoroscopic image match each other. The RI image memory 23 and the X-ray image memory 24 correspond to the RI distribution image storage means and the image storage means, respectively, in the present invention, and the image composition section 25 corresponds to the image composition means.

The RI distribution image and the image synthesized by the image synthesizing section 25 are displayed on the CRT 30 corresponding to the display means.

Next, referring to the flow chart of FIG. 3, the procedure of diagnosis by this gamma camera device will be described. Note that the region of interest is the lung, and the mixture of the substance that accumulates in the lung and the RI is already injected into the blood of the subject M, and the subject M is lying on the examination table 1. .

In step S1, the gamma camera 7 is moved to the vicinity of the region of interest of the subject M. Specifically, the movement control unit 21 drives the drive unit 13a to drive the gantry 5
Is moved along the body axis of the subject M. Then, the movement is stopped near the desired region of interest. At this time, the imaging center C of the gamma camera 7 corresponding to the region of interest of the subject M
_{Let A} be position O (see FIG. 1).

In step S2, the gamma camera 7 photographs the region of interest. At this time, the signal from the gamma camera 7 is converted by the A / D converter 22 and stored in the RI image memory 23 as an RI distribution image. A schematic diagram of this RI distribution image is shown in FIG. The center of the RI distribution image A corresponds to the imaging center C _A (position O). Since the position of the organ varies from person to person, the target organ is rarely displayed in the imaging visual field. Therefore,
The gamma camera 7 in step S2 is used to perform imaging, and the RI distribution image is displayed on the CRT 30 to determine whether or not the target organ is within the imaging field of view, and the process proceeds to the next step. Good.

In step S3, the gantry 5 is moved by a predetermined distance d. The gamma camera 7 and the X-ray detector 9b are supported by the support frame 11b while being held at a predetermined distance d.
The X-ray detector 9b is moved so that the imaging center C _B of the X-ray detector 9b coincides with the position O corresponding to the imaging center C _A on the region of interest by the gamma camera 7. (See FIG. 5). This movement is performed by the movement control unit 21 driving the driving unit 13a to move the gantry 5 by a distance corresponding to the predetermined distance d.

In step S4, an X-ray fluoroscopic image is taken. X-rays are emitted from the X-ray tube 9a, and the X-rays that have passed through the region of interest of the subject M are detected by the X-ray detector 9b. A signal corresponding to the detected transmitted X-ray is converted by the A / D conversion unit 22 and stored in the X-ray image memory 24 as an X-ray fluoroscopic image. A schematic diagram of the X-ray fluoroscopic image at this time is shown in FIG. The center portion of the X-ray fluoroscopic image B corresponds to the position O of the region of interest, and coincides with the imaging center C _A of the gamma camera 7. In the image B, the spine and ribs of the subject M and the contour of the body surface in plan view are shown.

In step S5, the image synthesizing unit 25 performs RI.
The RI distribution image of the image memory 23 and the X-ray fluoroscopic image of the X-ray image memory 24 are combined so that their central portions coincide with each other. This composite image is displayed on the CRT 30 (step S6). FIG. 7 shows a schematic diagram of the composite image displayed on the CRT 30. This composite image C is X
The ribs of the fluoroscopic image B are combined so that they are blocked by the lung part of the RI distribution image, that is, the RI distribution image A is arranged in front of the X-ray fluoroscopic image B. The operator can obtain an accurate position on the subject M by looking at the composite image displayed on the CRT 30 and from the relative positional relationship between the RI distribution image and the X-ray fluoroscopic image.

In this embodiment, X is used as the image pickup means.
Although the X-ray fluoroscopic image capturing unit 9 that obtains a fluoroscopic image is adopted, the present invention is not limited to this, and various imaging means such as a video camera can be adopted. Further, in this embodiment, the field of view of the gamma camera and the imaging means (the RI distribution image A of FIG. 4 and the X-ray fluoroscopic image B of FIG. 6) is used.
The size of the area is the same, but image pickup means having different photographing fields of view may be used.

Further, in this embodiment, the RI distribution image is photographed by the gamma camera, and then the RI image is photographed by the image pickup means. However, the order is not limited and the order may be reversed.

Further, in this embodiment, the supporting means for supporting the gamma camera and the image pickup means are moved with respect to the position-fixed examination table. However, the examination table is moved while the supporting means is fixed, and the respective images are taken. The region of interest may be located at the center.

[0024]

As is apparent from the above description, according to the present invention, the RI distribution image and the image photographed in a state where the photographing centers on the region of interest of the subject are coincident with each other have the same center portion. Since the images are combined as described above, the relative positional relationship between the two images on the combined image is accurately displayed on the display means. Therefore, the accurate position of the RI distribution image on the subject can be obtained without using the marker radiation source. Furthermore, since the marker radiation source is not used, the procedure for permitting the use of the radiation source is not required, and the apparatus is handled. Will be easier.

[Brief description of drawings]

FIG. 1 is a side view illustrating a schematic configuration of a gamma camera device according to an embodiment and a block diagram of an image processing unit.

FIG. 2 is a side view of FIG. 1 viewed from the body axis direction.

FIG. 3 is a flowchart showing an operation of the gamma camera device.

FIG. 4 is a schematic diagram of an RI distribution image.

FIG. 5 is a diagram showing a state of X-ray photography.

FIG. 6 is a schematic diagram of an X-ray fluoroscopic image.

FIG. 7 is a schematic diagram of a composite image.

[Explanation of symbols]

1 ... Examination table 5 ... Gantry 7 ... Gamma camera 9 ... X-ray fluoroscopic imaging unit 9a ... X-ray tube 9b ... X detector 20 ... Image processing unit 21 ... Movement control unit 22 ... A / D conversion unit 23 ... RI image memory 2 ₄ ... X-ray image memory C _A ... Imaging center of gamma camera CB ... Imaging center of X-ray detector A ... RI distribution image B ... X-ray fluoroscopic image C ... Composite image

Claims (1)

[Claims] 1. A gamma camera device for detecting a gamma ray generated from a radioisotope administered to a subject by a gamma camera to obtain a distribution image of the radioisotope (RI distribution image). A table, an image pickup means for picking up an image of a region of interest including the contour of the body surface of the subject, and a photographing center of each of the gamma camera and the image pickup means held at a predetermined interval to support the gamma camera and the image pickup means. The supporting means and the gamma camera and the imaging means are moved relative to each other by a distance corresponding to the predetermined interval so that the imaging centers of the gamma camera and the imaging means coincide with each other on the region of interest of the subject. A movement control means for controlling the RI and an RI for storing the RI distribution image obtained by the gamma camera.
Distribution image storage means, image storage means for storing the images obtained by the image pickup means, and image combination means for synthesizing the RI distribution images stored in both of the storage means so that the central portions of the images coincide with each other. And a display unit for displaying the combined image combined by the image combining unit.