Patients with IBD are exposed to high levels of ionizing radiation through CT scan diagnostic imaging: a five-year study

Abstract

Goals: The objective of this study was to assess the total effective dose of ionizing radiation from abdominal diagnostic imaging in patients with inflammatory bowel disease (IBD) over a 5-year period.

Background: Radiation exposure from diagnostic imaging is becoming increasingly common in IBD patients, in part due the availability of computed tomography (CT). Increased risk of malignancy has been associated with radiation exposure.

Study: This is a retrospective chart review. A university-based gastroenterology database was searched for patients with a diagnosis of Crohn's disease (CD) or ulcerative colitis (UC) seen between 2003 and 2008. The cumulative ionizing radiation exposure, expressed in milli-Sieverts (mSv), was then calculated from standard tables and by counting the number of abdominal imaging studies.

Results: Patients with CD had higher cumulative radiation exposure from diagnostic imaging than patients with UC (14.3 ± 1.45 mSv/5-y period vs. 5.9 ± 0.81 mSv/5-y period, P=0.00003). Three-quarters of the radiation exposure in both CD and UC was from CT scans. Thirty-four percent (127 of 373) of CD patients had CT scans, compared with just 20% (37 of 182) of UC patients. Importantly, 7% of CD patients were exposed to high levels of radiation (>50 mSv/5 y), in contrast to none of the UC patients.

Conclusions: Patients with IBD, and especially CD patients, undergo frequent diagnostic imaging and thus significant exposure to ionizing radiation. This radiation exposure reaches high levels in 7% of CD patients, mainly from CT scanning. Efforts should be made to minimize the radiation exposure from diagnostic imaging by reducing either the number of studies or radiation dose in modalities with ionizing radiation.