Specialist centres must take steps to reduce the amount of radiation people with Crohn's disease are exposed to from diagnostic imaging, radiologists have urged [1].

Patients with Crohn's disease may be particularly vulnerable to radiation owing to their young age at presentation and an elevated risk of some intestinal malignancies such as small bowel lymphoma.

Researchers estimated the cumulative effective dose (CED) of diagnostic radiation of 354 patients with Crohn’s disease treated at a tertiary centre.

They found that 55 patients, 15.5 per cent, had a 'high' CED – defined as greater than 75mSv.

Less than six imaging studies were performed per patient over the first five years of the 15-year study. During this period the mean CED was 7.9mSv, with CT accounting for 46.3 per cent of radiation exposure.

During the last five years, these figures had increased to almost seven images per patient and a mean CED of 25.1mSv. CT accounted for 84.7 per cent of radiation exposure at this time.

The likelihood of having a high CED was increased by an earlier diagnosis, upper gastrointestinal tract disease, the use intravenous steroids or infliximab, and multiple surgical procedures.

The authors said: "Strategies to reduce the effective dose of radiation incurred by patients undergoing CT imaging can be employed without sacrificing image quality and should be considered for all patients, particularly those who are likely to require multiple examinations."


[1] Crohn's disease: factors associated with exposure to high levels of diagnostic radiation
Gut 2008; Online first