Position reading-out device of gamma rays and position reading-out system of gamma rays

Abstract

The invention discloses a position reading-out device of gamma rays and a position reading-out system of the gamma rays. The position reading-out device of the gamma rays comprises a signal processing module, a discrimination module and a switch module, wherein the signal processing module is used for processing a current signal output by an SSPM (Security Service Provider Module) gamma ray detector and outputting an amplitude discrimination signal and a gating output signal; the discrimination module is used for discriminating the amplitude discrimination signal according to a pre-set signal and outputting a first control signal and a second control signal; the switch module is used for closing a corresponding switch according to the first control signal and the second control signal to output the gating output signal. By the aid of the position reading-out device of the gamma rays, an SSPM gamma ray detector array unit with the current signal which is higher than the pre-set signal is gated so that the influences on the resolution ratio of the position of the detector by dark noises are greatly reduced, and an application range of the SSPM detector in gamma detection is extremely expanded.

Description

technical field [0001] The invention relates to the technical field of gamma ray detection, in particular to a gamma ray position readout device and a gamma ray position readout system. Background technique [0002] In nuclear medicine imaging systems such as PET (Positron Emission Compute3Tomography, Positron Emission Computed Tomography), it is often necessary to detect the position, such as the direction, of gamma rays, and to determine the distribution image of the gamma ray source through reconstruction. When detecting gamma rays, the positional accuracy of the gamma rays will directly affect the final resolution of the image. Generally, the PET imaging device uses a gamma ray detector to detect the position of the gamma ray, and the gamma ray detector is mainly composed of a scintillation crystal and a photoelectric conversion device. Specifically, after the scintillation crystal converts the gamma rays into scintillation light with a wavelength in the range of 300-60...

AI Technical Summary

Problems solved by technology

[0004] Solution 1 in the related art has the following problems: the PMT quantum efficiency is low, the size is large, and it is sensitive to magnetic fields

Although SSPM can solve the above-mentioned shortcomings of PMT, the dark noise of SSPM is very large, for example, the dark noise count rate of 1 SSPM gamma ray detector array unit is as high as 10 7 , therefore, if the output signals of these SSPM gamma-ray detector array units are directly summed by using resistor network shunts, then the dark noise of all detector array units will be accumulated, making the position resolution seriously degraded

In addition, the dark noise of SSPM is very sensitive to temperature, which makes the position resolution very sensitive to temperature. At this time, the position of gamma rays will not be detected accurately

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