CZT-based Gamma Camera Software System Design And Quantitative Calculation Of Radionuclide Breast Image

The invention of the gamma camera has greatly promoted the development ofnuclear medicine, however, in the realization of high accuracy of patient diseasediagnosis at the same time, patients need to accept radiation dose is much more thanbefore. How to make the radiation dose that patients receiving as little as possible, andat the same time to ensure the accuracy of diagnosis is the unremitting goal in thedevelopment of nuclear medicine instrument. Improvement of radioactive isotopes,make it have better detection effect and low doses of radiation can realize the abovepurpose. Starting from the improved of instrument, improve the detection efficiencyand image quality, also can achieve the above purpose.According to the principle of gamma camera imaging structure, we improve fromtwo aspects of hardware and software.In the hardware part, mainly from the improvement of the design of collimatordetecting crystals and subsequent electronics circuit that used in the detector probe, sothat the gamma camera can:1, To detect position accurately, counting the energy eventscorrectly in a relatively short period of time;2, Make the introduction of the systemnoise as little as possible;In software part, mainly from the image processing steps after the camera originalimage:1, Based on image filtering de-noising pretreatment to reduce the image noiseinformation to highlight patients lesions information and organization structure;2,After preprocessing of the image quantitative analysis and calculation, auxiliarydiagnosis combined with clinical pathological theory and statistical law.Based on the above analysis, the research development and design based on thehigh resolution of CZT small gamma camera, this topic main work in this program is:1, Design the CZT gamma camera software system, and in view of the image dataprocessing module, nuclide breast quantitative analysis module, data quality controland correction module has carried on the detailed design and implementation; 2, Do quantitative analysis based on mammograms of CZT gamma camera image:first of all to normalization, filtering de-noising pretreatment, and ROI of the image areextracted, the thesis introduces in detail a histogram threshold segmentation based onmaximum entropy method to realize the automatic ROI, and has carried on the Matlabsoftware, and the paper also rivals move ROI method of implementation methods andexamples of Matlab are given, and then to extract the quantitative analysis of ROI,calculate the perimeter, area, diameter, length of circle, rectangle degrees, fine, ROI forcalculating grayscale average and gray variance, local ROI grayscale average grayvariance, ROI background grayscale average ratio, gray variance ratio and otherparameters, provide reference for clinical auxiliary diagnosis;3, Refer to the NEMA standard, according to the performance index of CZTdetector, design energy gamma camera calibration, uniformity correction method forcorrection and correction factor is presented for flow chart and software flow chart ofcorrection.