Introduction MR enterography (MRE) aids assessment of small bowel (SB) inflammatory bowel disease (IBD). We aimed to determine the frequency and clinical impact of incidental findings detected by MRE in patients with suspected or known Crohn’s disease (CD).
Methods We conducted a retrospective review of 948 MRE studies performed between June 2009 and December 2012 at our institution. Clinical data (demographics, disease characteristics and therapy) were obtained from electronic patient records. Incidental findings were defined as unexpected lesions in or outside the small intestine, previously unknown or unsuspected at the time of referral and unrelated to IBD.
Results Of 948 MRE studies 445 patients had a diagnosis of IBD, 385 had CD, 54 had ulcerative colitis and 16 had IBD unclassified (IBDU).
Of 385 CD patients, 224 were female, mean age 36 (range 12–72) and median follow up of 4 years (range 0–39). Abnormalities were noted in 285 scans, 162 active non-stricturing, 109 active stricturing and 13-fibrostenosis. Within active groups were 29 fistulae and 12 abscesses in 33 patients. Incidental findings included colitis (10), gallstones (17), ovarian cyst (15), sacroileitis (1), renal cyst (10), hepatic cyst (10), splenic haemangioma (1), mesenteric abscess (1), adrenal nodule (2), uterine fibroid (4), chronic pancreatitis (1) and splenomegaly (2) associated with portal vein thrombosis in and varices.
70 studies were performed in UC or IBDU; mean age 34 (range 15–82) 39 were female. Small bowel thickening with signs of active inflammation were seen in 9/13. Other findings included a fluid filled collection in the right ischio-anal fossa, pancreatic divisum, gallstones and liver, ovarian and Nabothian cysts, colitis in 6 and colonic polyps in 1.
Indications for MRE in the non-IBD group (503 patients) included iron deficiency anaemia, abdominal pain, weight loss, diarrhoea, vomiting, abnormal colonoscopy or intra-abdominal abscess. Findings included small bowel thickening (4), sub-acute small bowel obstruction (2), small bowel malignancies (2), small bowel stricture (1) and small bowel intussusception (1). Incidental findings included ovarian, hepatic and renal cysts, adrenal adenoma, ascites, splenic and liver haemangioma, AAA, PUJ obstruction, liver metastases, gallstones, gallbladder polyp, pelvic abscess, uterine fibroids, large bowel stricture, diverticular disease, cirrhosis, lymphadenopathy, horseshoe kidney, atrophic pancreas and acute appendicitis.
Conclusion A small but significant proportion of patients have important incidental findings at MRE. MRE can add meaningfully to the investigation of SB pathology. A careful selection of patients can be achieved through a collaborative approach between radiologists and clinicians.
Disclosure of Interest None Declared.