JPS58167985A - Scintillation camera - Google Patents

Abstract

PURPOSE:To minimize the distortion of an image by introducing an image reconstructive processing method with a computer. CONSTITUTION:When radiations from a radioactive isotope enter respective scintillators 11, 12..., a pulse signal is generated from PMTs (photomultiplier) 31, 32... corresponding to the incidence of the radiations. The detection signals are counted separately with counters 61, 62... to obtain numerous count outputs simultaneously. This data is written into a memory 73 under the control of a CPU72. The scintillators 11, 12... and collimators 41, 42... are rotated to write outputs of the counters 61, 62... into the memory 73 at each slight angle. After the end of the collection thereof, data is read out of the memory 73 to reconstruct a distribution image of the radioactive isotope by computation for the reconstruction of images.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synteresis camera that obtains a distribution image of radioactive isotopes (hereinafter abbreviated as RI).

Conventionally, one-type scintillation cameras have been popular as scintillation cameras, but they have problems such as significant distortion in images and low sensitivity.

The present invention differs in principle from conventional scintillation cameras by introducing an image reconstruction processing method using a combiator to provide a scintillation camera with no image distortion, high sensitivity, and high practical resolution. The purpose is to

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, a large number of elongated scintillators 11, 12, 13 degrees, . Specifically, nine elongated scintillators manufactured individually may be actually arranged in a row, or nine elongated scintillators may be arranged by dividing nine slender scintillators into sections. Scintillator 11°12.13.
The light emitted from each of the light guides 21, 22, .
23m...) A large number of PMTs (photomultipliers) 31.32,33. ... are guided to each of the photoelectric converters. Scintillator t1.1113.・
Parallel collimators 41, 42, 43, .
...is provided. And at least scintillators 11, 12. ...and collimator 41 = 42 m
. . . are rotated integrally by KO'~180° or 0°~360° with axis 0 as the central axis.

At a certain rotational angle position, the radiation from the RI passes through the collimators 41, 42 . Through scintillator 11.1
2. . . , 9, a PMT31°32, . This signal is AQ, Schheit Analyzer 51.52. ... to obtain detection signals corresponding to incident radiation within a predetermined energy window. This detection signal is sent to the counters 61, 62. The sand is counted by each of... Therefore, when the motor remains stationary for a certain period of time at a certain rotational angle position, each of the counters 61-62) performs a Kl count during that period, and a large number of count value outputs are obtained simultaneously. The scintillators 11, 12. If arranged according to the array position of ..., the second
The data P1 is as shown in the figure. This data is written to memory 73 through interface 71 under the control of CPU (central control unit) 72 .

Scintillator 11.12. ...and collimator 41゜4
As the counters 61, 62, . . . rotate, the outputs of the counters 5it, 62t, . By resetting . . . , a large number of data P1 to pm as shown in FIG.

After data collection is completed in this manner, the data is read out from the memory 73 and arithmetic processing for image reconstruction is performed. In this embodiment, a congeliation method is used as the image reconstruction algorithm.

That is, the above data P1 to pm and RI to be reconstructed
Considering the relationship with the distribution image, the well-known X@CT device (
This is the same as the relationship between projection data and tomographic images in a combinator tomography system. Therefore, in addition to X1iC
Image reconstruction techniques such as back projection with one shot and nine filter corrections can also be used. Here is the 115th! OK
As shown in FIG. 5K, the image is subjected to convolution integration using the Lupa 74, and is then back-projected using the pack radiator 75 and written into the image memory 7-6. Then, the image memory 76KR'I distribution image is reconstructed, so CR
It can be displayed on 77 display devices.

Next, an embodiment of the irises 2 will be described with reference to FIG. As shown in this figure, parallel collimators 41, 42t,
Each shield plate of... is at a predetermined angle #(0'(-
≦90°)
Each shield plate is perpendicular to the plane formed by the scintillators 11, 11...). The other configuration is the same as that in FIG. 1, and the center position of each data of the obtained nine-taters P1 to Pm is set as the nine-signal obtained from the scintillator separated by L from the central axis O of one rotation, and the same image is obtained. Perform the reconstruction method. Then, the images before and after the distance d corresponding to the distance LiC are scattered and blurred, and an RI distribution image on Senryo near the distance d, which converges at the same position near the distance d, is obtained. Therefore, once the data is stored, a tomographic image at any distance d can be obtained by arbitrarily setting L using arithmetic processing.

In addition, in the embodiment of FIG. 3, as shown in FIG. 4, scintillators 11, 12, . . . . The collimators 41, 42... ...
and the scintillators 11, 12°, and so on are lined up in a straight line, then the radiation passes through the collimators 41e41 and enters each of the scintillators 11, 12, and so on, and nine rays pass through each scintillator. Since the amount of radiation incident on the adjacent scintillator is reduced, the resolution is improved even for high-energy radiation.

As described above, the embodiments have been described.1 According to the present invention, a principle different from that of conventional scintillation cameras is adopted, and an image reconstruction method using a combinator is introduced.There is no rounding, no image distortion, and high sensitivity. This makes it possible to construct a scintillating camera with a high practical resolution.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a first embodiment of the present invention, FIG. 2 is a graph representing data, FIG. 3 is a schematic diagram of the second embodiment, and FIG. 4 is a schematic diagram of a modified example. 11.12. ...Scintillator 2t, 22.・・・
・Ride Buid 31.32. ... P M T
41, 42. ... Collimator 5L52 - ... Arm height analyzer 61.62. ···counter
71...Interface 72...CPU
73...Memory 74...Conlpara 75...Pack f logicer 76...Image memory 77...CRT device applicant Shimadzu Corporation Sho 2

Claims (1)

[Claims] (1) A large number of substantially elongated scintillators are arranged in a plane in the width direction, and a signal is obtained by detecting the light emitted from each scintillator using a large number of photoelectric converters without depending on the position in the length direction of the emitted light. , the scintillator is rotated to simultaneously obtain nine signal Kl data from the multi-O photoelectric converter at every minute angle, and the data is subjected to image reconstruction processing to reconstruct a distribution image of radioactive isotopes. - (2) Parallel collimators for regulating the direction of radiation incidence in the width direction of the plurality of elongated scintillators are provided, the parallel collimators are tilted at a predetermined angle, and the predetermined distance is from the center of rotation of the scintillators. The aforementioned image reconstruction process is performed using the signals of the scintillators at nine distant positions as data centers, and the distribution image of radioactive isotopes in nine tomographic planes separated by a predetermined distance from the scintillators is reconstructed. A scintillating camera according to claim 1.