Cumulative lifetime attributed risks for patients subjected to contrast enhanced chest CT examinations

Abstract

The main aim here is to estimate the cumulative lifetime attributed risks (LARs) for patients subjected to contrast-enhanced chest computer tomography (CECCT). Further, the impact of the contrast media on the organs doses (ODs), effective dose (E*), LARs and scan acquisition parameters were assessed. The ODs, and E* of the CECCT scan for 17 patients were obtained without-contrast (S1) and with-contrast (S2) using the commercial software CT-EXPO. The LARs were calculated using age- and- gender specific risk factors. The relationship between the CT dose metrics (CTDIvol and DLP), mAs and scan-length were established using the Pearson's correlation coefficient-test. The Wilcoxon pairs t-test was used to determine the statistical differences between all quantities in both chest CT series. No significant differences were found between the CT scan series S1 and S2 in all the determined quantities including: CTDIvol (p = 0.772), DLP (p = 0.092), mAs (p = 0.450) and E* (p = 0.111). The ODs were higher with contrast media, particularly stomach and bone marrow. The LARs of developing lung cancer were particularly high for the females in their 60's about 1 in 3000 (or 0.03%). The highest LARs of all organ cancers reported were higher in females comparing to males 0.03% comparing to 0.01%). Female patients are at higher risk of developing cancers than males while undergoing CECCT wherein contrast media can contribute to increasing organ doses.