H. A. Ayoub, M. H. Dahawy, A. Elnadi and Sh. A. El Tammimy
Enhancement of the lesion detectability for PET/CT scanner is performed by utilizing the exclusive True X reconstruction algorithm. Evaluation of the optimum contrast ratio is obtained by manipulation of the conventional Iterative program (OSEM) and True X- reconstruction algorithms. NEMA Jaszczak phantom was acquired on biography 64 PET/CT. The five hot spheres of Jaszczak phantom were filled by18 Fluoro- Deoxy – Glucose (18FDG) with 2.5: 1 contrast ratio to the background. Image quality was visually assessed and contrast measurements were computed against known phantom activity to determine the quantization accuracy for different size lesions. The enhancement of visibility for hot spheres was done by utilizing the new reconstruction algorithms (True X) . The contrast ratio improved by increasing the hot spheres diameter and by appling more number of iteration for both conventional Iterative program (OSEM) and the reconstruction algorithms True X . The maximum contrast ratio by using OSEM program was 1.8848 for hot sphere of diameter 24 mm and on the other hand when using True X algorithms was 2 . 0525for the same hot sphere. The True X reconstruction – recovery technique improved the accuracy of measured activity values for small hot lesions. The resolution Was improved as explored from center to periphery of lesion, and for either large or off – centered phantom are needed to quantify imaging performance with such PET/CT system. A trail was performed to quantify imaging performance by up to date PET /CT system
