د.محمد عامر الجماعي2026-06-252026-06-25https://dspace.academy.edu.ly/handle/123456789/2374The contribution of renal , liver , bone and thyroid examinations to the pediatric effective dose and percentage cancer risk factor were 1.874mSv (0.026%) , 0.3947 mSv (0.022%) , 2.1031mSv (0.0105%) and 1.5753mSv (0.078%) respectively. The mean effective dose equivalent per pediatric patient in this study was 1.4867 mSv. Regarding to computed tomography scanning , The highest effective dose was recorded from GE scanner (19.9 mSv) for chest scan at 240 mAs and 120 kVp , while the smallest effective dose was recorded by Siemens (0.3 mSv) for brain scan at the same previous values of mAs and kVp. This study also reveals The percentage risk factors due to brain scan with the three different scanners are: 0.088 , 0.031 and 0.016 for GE , Philips and Siemens respectively, it’s clear that GE brain scanner will produce high risk factor compared with the two others , this is of course due to the high effective dose produced by this scanner.In light of the rapidly increasing frequency of patient nuclear medicine examinations and as a part of a nationwide survey to estimate patient exposure to radiation from diagnostic nuclear medicine and computed tomography at Tripoli Medical Center. The purpose of our study was to assess the effective dose and cancer risks attributable to radiation from two different imaging modalities. Organ effective doses and cancer risk factor as a function of different age groups (1< - 45 years) for 400 hundred cases for different organs ( Renal , Thyroid , Bone , Chest , Pelvis , Brain and Abdomen ) were estimated for the two imaging modalities examinations by using RADAR and OLINDA software package. The results indicate that, the most frequent scan was renal examinations (60%), followed by liver (25%) , bone (10%) and thyroid (5%). The collective effective dose for the cases under 15 years old was 1.354 human-Sv , which contributed for all patients.radiation dose and risk form two different imaging