Assessment of Image Quality Parameters for Computed Tomography in Tripoli, Libya

Computed tomography (CT) is a powerful imaging technique widely used. In Libya, the performed CT examinations are increasing, and the high doses associated with those CT examinations must be controlled. The aim of this study is to investigate the performance of several CT scanners image quality used in different medical clinics in Tripoli.Philips CT phantom (Serial Number: 4535-671-35962) was used to acquire images, under the same imaging parameters (120 kVp, 200 mAs, image size of (512 x 512) by implementing the IAEA standards for image quality control (QC). Images were obtained in the DICOM format from each CT.Results showed that there was no major difference in uniformity between the selected regions of interest ROIs in X and Y- directions within all obtained scans, with the coefficient of variation %CV varying between 0.330 and 0.528. The linearity test of all scans exhibited the same trend as it was provided by the phantom manual; the lowest mean pixel intensity value was 956.678 for polyethylene and the highest mean pixel intensity value was for Teflon 1945.347. The contrast C and CNR, between the water layer and Teflon was the highest value varied between 172.913 and 262.199, and the lowest value, varied between 0.844 to 19.015.