Risk of Radiation and Choice of ImagingHerfarth H. · Palmer L.
Department of Medicine, Division of Gastroenterology and Hepatology, University of North Carolina, Chapel Hill, N.C., USA
Radiological imaging plays an important role in the diagnosis and management of patients with inflammatory bowel diseases (IBD). The barium or contrast techniques enteroclysis (SBE) and small bowel follow through (SBFT) are still the mainstays in small bowel imaging. However, abdominal CT and MRI, including enteroclysis, have comparable sensitivity and specificity in detecting intestinal pathologies and have gained in popularity over conventional techniques. The cancer risk associated with diagnostic procedures employing radiation has been receiving increasing attention over the last few years. The cumulative exposure to ionizing radiation may be a specific concern in young patients with IBD, who are more susceptible than adults to the risks of ionizing radiation. Substantial exposure to radiation seems to be mainly caused by CT examinations of the abdomen. For that reason, imaging methods such as MRI or ultrasound should be considered first when debating between alternative imaging strategies, particularly in young IBD patients. The major drawbacks of MRI are its limited availability and greater costs compared to CT. Moreover, the diagnostic accuracy of abdominal ultrasound is clearly operator dependent, which limits the range of its applications. In light of these concerns, diagnostic imaging studies using radiation will continue to play an important role in the evaluation of patients with IBD. Therefore, we need to develop low-radiation imaging protocols or improve access to MRI imaging procedures. We also need to identify subsets of IBD patients who are at greater risk of a significant lifetime exposure to radiation and develop methods to monitor their radiation exposure rate.