Significant but reasonable radiation exposure from computed tomography-related medical imaging in the ICU

Admission to an intensive care unit (ICU) is associated with increased medical imaging and radiation exposure, yet few studies have estimated the risk of cancer associated with these examinations. The purpose of this study was to review computed tomography (CT) scans performed on patients admitted to two urban academic ICUs, predict their radiation exposure, and calculate their estimated lifetime attributable risk of cancer (LAR). An electronic chart review was performed on all CT scans performed between January 2007 and December 2011. The estimated effective dose of radiation was calculated for each CT, and the LAR for each patient was predicted. Mean radiation exposure was 22.2 ± 25.0 mSv with a mean LAR of 0.1 ± 0.2 % and a median of 0.6 % with a range of <0.001 to 3.4 %. Our cohort received radiation doses higher than recommended by guidelines; however, the critical nature of their admission may have warranted these imaging studies. Estimated risk of cancer in this population was overall low.