| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem wherein sensitivity correction has been insufficient in conventional iterative image reconstruction methods with a PSF model incorporated.SOLUTION: A point radiation source is arranged in a detector ring, and radiation is measured by a plurality of PET detectors positioned in the direction of one tangent of the detector ring 1 to acquire projection data (S1). The projection data is approximated by the Gaussian function separately on the right and left of its peak position to determine a left-side standard deviation σand a right-side standard deviation σ(S2), and t values of σand σare plotted at radial positions of corresponding PET detectors to model σand σ, as functions of radial positions (S3). A normalization coefficient of the Gaussian function is modeled as a function of a radial position through the use of σand σ(S4), and modelled σand σand the Gaussian function having the normalization coefficient are incorporated to a system matrix to improve an iterative image reconstruction method (S5). A reconstructed image is generated through the use of a successive approximation image reconstruction method (S6). |
