E-ISSN 1305-3612
1 Department of Medical Physics, Dokuz Eylül University Health Sciences Institute, İzmir, Turkey  
Diagn Interv Radiol ; : -



Purpose: Size specific dose estimates (SSDEs) are the latest focus of interest among medical physicists studying on the radiation dose to the patient in computed tomography (CT). This study aims to make conversions from CTDIvol to SSDE and investigate the relationship between mean SSDE ( ) and central SSDE (SSDEcenter) values for pediatric patients of different age groups undergoing chest, abdomen and pelvis scans.


Methods: 105 consecutive pediatric CT exams of chest, abdomen and pelvis (CAP) have been examined in this retrospective study which was conducted on 3 separate groups of patients; ages between 0-5, 6-10 and 11-16. A MATLAB program has been developed to determine   values for each patient along 6 subregions: chest (C), abdomen (A), pelvis (P), chest and abdomen, abdomen and pelvis, and CAP. On the other hand, SSDE values derived over the slice at the center of each scan range, SSDEcenter, have been recorded.   and corresponding SSDEcenter results have been compared for each patient group.


Results: Root mean square differences (RMSD) between   and SSDEcenter values have been observed to change between 0.13 mGy and 2.1 mGy through all groups and subregions, which correspond to 1.2% and 11% respectively.


Conclusion: In pediatric CT exams involving CAP region, CTDIvol and the water equivalent diameter at the middle of the scan range can be used to provide a reasonable estimation of mean SSDE with a RMSD of 11% at most. 

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