Single-photon fault imaging method and system

Abstract

The invention relates to a single photon fault imaging method and system, the method can acquire Gamma photons by a photomultiplier tube array through collision on a scintillation crystal to generate a fluorescent signal, the fluorescent signal is converted into a fluorescent digital signal by a data acquisition module, the fluorescent digital signal is sent into a positioning module to perform positioning calculation, the positioning data can be formed and all effective data can be converted into images, the algorithm adopted in the positioning calculation is maximum likelihood positioning algorithm guided by a mass center, at first the Gamma photon collision position can be calculated with a mass center method, then the Gamma photon collision positioning data can be formed by accurately estimating with local two-dimension maximum likelihood method in a selected scope; the system comprises the scintillation crystal, the photomultiplier tube array, the data acquisition module, the positioning module and an imaging module. The positioning accuracy of the invention is approximate to the maximum likelihood positioning method, thereby shortening the calculating time and reducing the requirements for the computer hardware and the memory space greatly.

Description

technical field [0001] The present invention relates to a single-photon tomographic imaging method, and also relates to a single-photon tomographic imaging system using this method, which can be mainly used for clinical diagnosis of diseases, monitoring of nuclide treatment process and scientific research (including animal imaging system), etc. . Background technique [0002] Single-photon emission computed tomography (SPECT) is an important disease diagnostic equipment and can be used to monitor the nuclide treatment process. It receives gamma rays through scintillation crystals, and produces fluorescent flashes at the collision positions of gamma photons. The photomultiplier tube array behind the scintillation crystal receives the fluorescent flashes, generates corresponding fluorescent signals, and converts the fluorescent signals into fluorescent digital signals through the data acquisition module and sends them to the positioning module for positioning calculation, form...

AI Technical Summary

Problems solved by technology

An important technical issue of this equipment is how to calculate the coordinate value of the gamma photon impact position. There are currently two calculation methods, one is the centroid positioning algorithm, and the other is the maximum likelihood positioning algorithm. The calculation process of the centroid positioning method is simple. , is easy to implement and has been widely used. However, this method does not consider the statistical fluctuations of scintillation photons and the nonlinear response of photomultiplier tubes, and suffers from severe spatial distortion. Although nonlinear correction techniques are widely used, it is difficult to Determine the true deformation map, more precisely there is no true deformation map, so the rectified image still has residual positioning error

In order to improve efficiency and obtain unbiased position estimates, the maximum likelihood method and other methods based on statistical tests have been gradually developed. Due to the huge amount of calculation of the complete two-dimensional maximum likelihood positioning algorithm, it has not yet been practically applied. Feasible, can not be promoted in practice

Images