Diagnostic imaging and radiation exposure in inflammatory bowel disease

Abstract

Diagnostic imaging plays a key role in the diagnosis and management of inflammatory bowel disease (IBD). However due to the relapsing nature of IBD, there is growing concern that IBD patients may be exposed to potentially harmful cumulative levels of ionising radiation in their lifetime, increasing malignant potential in a population already at risk. In this review we explore the proportion of IBD patients exposed to high cumulative radiation doses, the risk factors associated with higher radiation exposures, and we compare conventional diagnostic imaging with newer radiation-free imaging techniques used in the evaluation of patients with IBD. While computed tomography (CT) performs well as an imaging modality for IBD, the effective radiation dose is considerably higher than other abdominal imaging modalities. It is increasingly recognised that CT imaging remains responsible for the majority of diagnostic medical radiation to which IBD patients are exposed. Magnetic resonance imaging (MRI) and small intestine contrast enhanced ultrasonography (SICUS) have now emerged as suitable radiation-free alternatives to CT imaging, with comparable diagnostic accuracy. The routine use of MRI and SICUS for the clinical evaluation of patients with known or suspected small bowel Crohn’s disease is to be encouraged wherever possible. More provision is needed for out-of-hours radiation-free imaging modalities to reduce the need for CT.

Keywords: Diagnostic medical radiation, Inflammatory bowel disease, Small bowel follow-through, Computerised tomography, Nuclear medicine, Magnetic resonance enterography, Small intestine contrast-enhanced ultrasonography

Core tip: Due to the chronic and relapsing nature of inflammatory bowel disease (IBD), patients are at risk of exposure to potentially harmful cumulative radiation doses in their lifetime. Computed tomography (CT) imaging remains responsible for the majority of this radiation exposure. As well as new reduced radiation CT imaging techniques, radiation-free alternatives magnetic resonance imaging and small intestine contrast enhanced ultrasonography have emerged, offering comparable diagnostic accuracy. In this review we explore the proportion of IBD patients exposed to high cumulative radiation doses, the factors associated with higher radiation exposures, and we compare conventional imaging with newer radiation-free imaging techniques for the evaluation of patients with IBD.