Correlation between Age and Abdominal Diameter for Estimating Size-Specific dose in Pediatric CT examination

Abstract

This study aims to investigate the correlation between abdominal diameter against the their ages in pediatric Computed Tomography (CT) examination. The retrospective images from 96 patients ranging from 0–16 years scanned by the Siemens Somatom Go Top 128 Multi-slice CT scanner were evaluated. In a total of 46 patients were scanned by tube current modulation (TCM) approach and the remaining 50 patients were examined whitout TCM. The effective diameter (Deff) for every patient was automatically calculated using IndoseCT. The evaluation of the size and age correlation was carried out using a regression approach from AAPM Task Group 204. In addition, size-specific dose estimate (SSDE) was also calculated using IndoseCT. The results shows that the patient’s diameters increase along the increase of ages (R2 > 0.68) with rapid growth in the ages of 0-1 years. It is also found that the increase in the patient’s diameter leds to the decrease of SSDE in the non-TCM protocol, while the trend in the TCM protocol is different. The SSDE had a tendency to increase along with the increase in patient sizes (R2 < 0.40).