Incidental findings at MRI-enterography in patients with suspected or known Crohn's disease

Abstract

Aim: To determine the frequency and clinical impact of incidental findings detected with magnetic resonance imaging (MRI)-enterography in patients with suspected or known Crohn's disease (CD).

Methods: Incidental findings were defined as unexpected lesions outside the small intestine, not previously known or suspected at the time of referral, and not related to inflammatory bowel disease. Through a systematic review of medical charts we analyzed the clinical impact of incidental findings, and compared the MRI findings with subsequent diagnostic procedures.

Results: A total of 283 patients were included in the analysis, and MRI detected active CD in 31%, fistula in 1.4% and abscess in 0.7%. Extra-intestinal findings not related to CD were recorded in 72 patients (25%), of which 58 patients (20%) had 74 previously unknown lesions. Important or incompletely characterized findings were detected in 17 patients (6.0%). Incidental findings led to 12 further interventions in 9 patients (3.2%) revealing previously unknown pathological conditions in 5 (1.8%). One patient (0.4%) underwent surgery and one patient was diagnosed with a malignant disease. MRI detected incidental colonic lesions in 16 patients of which additional work-up in 4 revealed normal anatomy. Two patients (0.7%) benefitted from the additional examinations, whereas incidental findings led to unnecessary examinations in 9 (3.2%).

Conclusion: In a minority of patients with suspected or known CD, important incidental findings are diagnosed at MRI-enterography. However, a substantial number of patients experience unnecessary morbidity because of additional examinations of benign or normal conditions.

Figure 1

Incidental findings at MRI-enterography. A: Abdominal aortic aneurysm (arrow). CT scan confirmed the aneurysm and ruled out rupture; B: Atypical hepatic hemangioma (arrow). The results of ultrasound-guided biopsy were benign; C: Large bladder leading to diagnostic work-up and diagnosis of prostate cancer (arrow); D: A lesion with a diameter of 6 cm in the small pelvis (arrow) was confirmed with transvaginal ultrasound. Surgery showed a torquated leiomyoma in the top of the uterus.