JPH01250881A - Gamma camera tomography device - Google Patents

Abstract

PURPOSE:To enable the tomographic image of a wide visual range without rotating a detector by producing the tomographic image in overlapping data collected via two gamma cameras and collimators which are disposed oppositely to each other respectively. CONSTITUTION:Gamma rays emitted by individual slices 1-5 are incident upon the slant hole collimator 10a in its positions A-G as to the gamma camera 10, and the slant hole collimator 20a in its positions (a)-(g) as to the gamma camera 20 respectively. Thus, the detected data collected during a fixed period of time are stored in memories 12 and 22. Then, the data of the memory 12 and the data of the memory 22 are added up by an adding circuit 30, so that the data for the individual slices are reconstituted. The data of one of the memories are shifted in address, but depending upon a slide position settled for this reconstitution. By this method, without rotating the gamma camera detector as in the conventional way, the tomographic image can be obtained over the broad range of vision.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is utilized in the field of measuring distribution images of radioactive isotopes (R1).

The present invention relates to a gamma camera tomographic imaging apparatus, and more particularly to a tomographic imaging apparatus using a gamma camera, and particularly relates to improvements in its imaging.

[Prior Art] In conventional tomographic imaging using a gamma camera, reconstruction is performed using data collected by rotating a detector in the body axis direction of the subject.

[Problem to be solved by the invention] In such conventional examples, it is necessary to rotate the detector around the subject in either direction, and during this rotation, the detector and the subject collide. There is a problem in that the rotation of the detector must be safely controlled to prevent this from occurring.

Furthermore, it is impossible to perform tomographic imaging with a wide field of view of the examiner's whole body.

It is an object of the present invention to provide a gamma camera tomographic imaging device that does not require rotation of the detector, so there is no possibility of collision between the detector and the subject, and that performs tomographic imaging within a relatively wide field of view. It is to provide.

[Means for Solving the Problems] The above object is to provide two gamma cameras disposed facing each other, each equipped with a collimator that is a combination of slant hole collimators or a combination of a slant hole collimator and a parallel collimator. This is achieved by including a processing circuit that superimposes data collected through a collimator to create a tomographic image.

For example, when adding the detection data of each camera and writing it to the frame memory, the address of one detection data is
Depending on the set slice position, this can be achieved by inserting a shift circuit in front of the adder circuit.

[Function] The respective axes of the slant hole collimators of the two gamma cameras facing each other intersect many times, and when detecting data at the intersection points on a common set slice position, each of the intersection points is If the address of the detection data corresponding to one collimator position differs from the address of the detection data corresponding to the other collimator position, shift one of the addresses to match the other and overlap. By adding them, the intersection point at that slice position is emphasized and imaged.

[Example] A preferred embodiment of the invention will be explained based on the drawings.

FIG. 1 is an explanatory view of the structure and operation of one embodiment.

10 to det, l and 20 to det.

2 is a gamma camera or detector, and 10a and 20a are slant hole collimators.

A memory 12 is connected to the gamma camera 10 and stores data detected via the slant hole collimator 10a. In this memory 12, A, B, C, and D of the illustrated example are stored at each position of the slant hole collimator section 10a.
, E, F, and G, the detected data is recorded.

Reference numeral 22 denotes a memory connected to the gamma camera 20, in which detection data of the gamma camera 20 is similarly stored at addresses corresponding to a, b, c, d, e, f, and g in the illustrated example.

In the illustrated example, the gamma rays emitted in each part of slices 1 to 5 are emitted at positions A to G of the slant hole collimator 10a for the gamma camera 10, and at positions A to G of the slant ball collimator 20a for the gamma camera 20.
” are respectively incident on g.

In this way, the detection data collected for a certain period of time is
Stored in memory 12.22 as described above.

Here, the data of each slice is reconstructed by adding the data of the memory 12 and the data of the memory 22 by the adder circuit 30.

During this reconfiguration, it is necessary to shift the address of one of the data depending on the set slice position.

For example, for reconstruction of slice 1, gamma camera 1
Each data of the position A of the slant hole collimator glloa of 0 and the position C of the slant hole collimator part 20a of the gamma camera 20, and similarly each data of the positions B and d, are sequentially C and e, D and f, Similarly, it is necessary to overlap the two data for B and g, and by shifting the addresses, the contents of slice 1 are emphasized, output from the memory 32, and displayed on a monitor (not shown).

In addition, in slice 2, each intersection point on this slice is taken, and the position A on the gamma camera 10 side and the position Mb on the gamma camera 20 side are determined, and in the same manner, in slice 3, the intersection point is located at position HA and position Mb. a. Reconstruct the data of each slice in the same manner.

The data for each slice can be stored in memory 32 and displayed as before, or a cross-sectional view can be reconstructed from each slice data.

Note that since the shift amount of the data address applied to one gamma camera changes depending on each slice position, the shift circuit 11824 is provided with a slice setting device (not shown).

Instead of shifting by the shift circuit in the previous embodiment, one of the gamma cameras may be moved up and down or left and right to overlap and reconfigure.

Furthermore, the collimator attached to the gamma camera is not a slant-hole collimator, but a combination of a parallel collimator and a slant-hole collimator may be used.

In addition, as an extended use of the present invention, if the camera is moved in the direction of scanning the whole body, the field of view can be expanded and the whole body can be scanned! fi
Layer cross section concave cross section diagram.

[Effects] According to the present invention, there is no need to rotate the gamma camera detector as in the conventional example, so there is no need to worry about collision between the detector and the subject, and tomographic images can be obtained over a wide field of view. .

[Brief explanation of the drawing]

FIG. 1 is an explanatory view of the structure and operation of one embodiment of the present invention. IO and 20 are gamma cameras or detectors, 10a and 20
a is a slant hole collimator, 12, 22, and 32 are memories, 24 is a shift circuit, and 30 is an adder circuit. Patent applicant: Shimadzu Corporation No. 1 V

Claims (1)

[Claims] 1. Two gamma cameras placed opposite each other with collimators in a combination of slant-hole collimators or a combination of a slant-hole collimator and a parallel collimator, and superimposing the data collected through each collimator. 1. A gamma camera tomographic imaging apparatus, comprising a processing circuit that creates a tomographic image.