Establishment of exposure levels for computed tomography examinations based on clinical indication, patient gender and size and the use of contrast in Lebanon.

Abstract

This study aims to establish exposure levels for computed tomography (CT) examinations performed on adult patients based on clinical indication (CI), patient gender and size and the use of contrast in Lebanon. The volume CT dose index (CTDIvol), size-specific dose estimate (SSDE) and dose length product (DLP) were collected between January 2010 and December 2021 from 14 Lebanese hospitals. The data were collected from at least 20 patients for 15 common groups of CIs in the head, thorax, abdomen (AB), abdomen-pelvis (ABP) and thorax-abdomen-pelvis (TABP) regions. The exposure levels were calculated for each group of CIs, patient gender and size and depending on the use of contrast as the third quartile of the CT scanners’ median values of CTDIvol, SSDE and DLP. The exposure levels in term of CTDIvol (DLP) were 65, 15, 9, 9 and 12 mGy (1105, 483, 522, 440 and 610 mGy.cm), respectively, for Head/Hemorrhage, ABP/Appendicitis, AB/Abdominal pain, Thorax/Covid-19 and TABP/Trauma. Median DLP values for male, large size patients and those administered with contrast were significantly higher (p<0.05) than those from female, medium size patients and those without contrast media, respectively, for all the groups of CIs in the thorax, AB, ABP and TABP regions. The established exposure levels were higher than those from the literature pointing up the need for a dose optimization strategy to protect the patient from the harmful effects of radiation.