Incidental findings at MRI-enterography

MRI is increasingly used in the assessment of small bowel CD. Unlike conventional radiology, MRI enables visualization of disease extension beyond the intestinal wall, i.e., abscesses and fistulas. However, some extra-intestinal findings are unexpected and without relation to CD. The ability to detect incidental findings presents a clinical dilemma. On one hand, modern imaging techniques may detect early extra-intestinal malignant disease or disease requiring clinical intervention, thereby reducing morbidity and mortality. On the other hand, incidental findings may lead to further diagnostic work-up or surgery of benign lesions causing increased morbidity.

A research article to be published on January 7 , 2010 in the World Journal of Gastroenterology addresses incidental findings in MRI-enterography in patients with suspected or known CD. Only few studies have dealt with incidental findings in abdominal MRI. In the present study, MRI-enterography revealed incidental findings located outside the small intestine which were not related to CD in 25% of patients resulting in additional examinations in 5%.

Additional investigations confirmed abnormal lesions in 1.8%, and one patient had a malignant disease. Two patients benefitted from the additional examinations (aortic aneurysm and prostate cancer) whereas incidental findings led to unnecessary examinations in 9 patients. Detection of extra-intestinal manifestations of CD was rare (1.8%). Hence, incidental findings are common in patients having MRI for evaluation of small bowel CD. Additional examinations reveal important disease in a minority of patients. However, a substantial number of patients experienced unnecessary morbidity because of the additional investigations of benign or normal conditions. The detection rate of important incidental lesions not related to CD is too low to be an argument in itself for performing MRI-enterography in this group of patients.