Patent ID: 9483850
Filing Date: 2016-11-01
CPC Classification: G06T

Claim Text:
1. A method for determining a position of a source, comprising: obtaining prompt data and related delayed data from a Positron Emission Tomography (PET) scanner, the delayed data includes random events; generating a sinogram from the prompt data; generating crystal efficiency correction factors by performing a normalization calibration based on the obtained delayed data; performing normalization correction on the generated sinogram based on the crystal efficiency correction factors to generate a corrected sinogram; rebinning the corrected sinogram to generate a plurality of two-dimensional sinogram slices; and determining a central axis for each of the plurality of two-dimensional sinogram slices using a center estimation process, wherein the step of determining the central axis for each of the plurality of two-dimensional sinogram slices further comprises: performing a thresholding process on each of the plurality of two-dimensional sinogram slices to convert the respective slice to a binary image to generate a plurality of binary images; performing morphology operations on the respective binary image to generate processed binary images; detecting left and right edges in the respective processed binary images; excluding edge outliers, within the plurality of processed binary images, that correspond to crystals at transversal edges of each module; determining a mean curve of the left and right edges; and applying sinusoidal function curve fitting to the mean curve of the left and right edges in order to determine the central axis within the sinogram.