Estimation of anatomical dimensions of the thorax from computed tomography images of the adult and pediatric Indian population for developing optimal radiological protocols

Abstract

Purpose: Ionizing radiation has been extensively used for medical diagnosis since its discovery in 1895; however, excessive use can lead to deleterious effects. Prior knowledge on radiological protocols based on simulations would be a practical tool for optimal use of radiation. Materials and Methods: Scan length of the thorax was measured from computed tomography (CT) topographic images and cross-sections at three levels of the thorax were measured from tomographic images of 500 adults and 340 children who had undergone CT thorax examinations using Centricity workstation software. The effective diameter (ED) of the thorax was calculated from anterio-posterior (AP) and transverse anatomical dimensions. Results: A 17% increase in scan length was observed for 6–10 years age group compared to 0–5 years, whereas there was marginal increase for 11–15 years of age. A 11.5% increase was observed for 16–18 years compared to 11-15 years age group. The cross-sectional phantom dimensions were calculated from ED measurements obtained from three regions of the thorax. Conclusions: This study has provided age- and gender-specific reference scan lengths, AP and transverse dimensions and ED for radiological examinations of the thorax. This information is useful to develop age- and gender-specific preset protocols and fabricate phantoms of the thorax for the pediatric and adult Indian population.

Keywords

• effective diameter
• phantom
• radiation safety
• thorax