P208. Is availability of MR Enterography reducing avoidable use of ionising radiation in diagnostic imaging for Crohn's Disease?
A. Smyth1, D. Gibson1, D. Murphy2, D. Keegan1, G. Cullen1, H. Mulcahy1, D. Malone2, G. Doherty1, 1St Vincent's University Hospital, Gastroenterology, Dublin, Ireland, 2St Vincent's University Hospital, Radiology, Dublin, Ireland
Magnetic Resonance Enterography (MRE) has been increasingly adopted as the imaging modality of choice for patients with small bowel Crohn's disease, replacing barium studies and Computerised Tomography (CT). MRE has similar sensitivity to CT for detection of small bowel inflammatory changes but has the advantage of no exposure to ionising radiation. We aimed to evaluate whether the availability of MRE has diminished or eliminated avoidable radiation exposure related to diagnostic imaging in this patient group.
Retrospective analysis of a prospectively maintained database of 3000 patients with IBD in a large tertiary referral hospital was performed. All patients diagnosed with Crohn's disease during the period of 01-January-2009 until 15-October-2012 were identified. A review was performed of all abdominal imaging done at the study centre – MRE, abdominal CT and barium small bowel studies (MR pelvis for evaluating peri-anal complications was excluded). Studies performed elsewhere and reviewed at the study hospital were also included.
122 patients were entered into the database as having a new diagnosis of Crohn's disease between 01-January-2009 and 15-October-2012. 58 (47.5%) were female. The median age at diagnosis was 28 years (median interquartile range 23–40). A total of 62 MRE studies were performed in 52 patients (42.6%). Eight patients had two or more MRE studies performed during the follow-up.
26 patients (21%) had a barium small bowel examination.
A total of 83 abdominal CT studies were performed in 52 patients (42.6%). Of the 83 CT studies performed in this group, 35 (42%) were performed as an emergency investigation. 18 patients had 2 or more abdominal CT studies performed (range 2–6).
55 patients (45%) had an abdominal CT or barium examination performed in a non-emergency setting.
This study shows that there is still significant use of ionising radiation, sometimes performed repeatedly, in a non-emergency setting. 45% of this young patient cohort with newly diagnosed Crohn's disease received avoidable radiation exposure related to diagnostic imaging. While MRE is now available, waiting times often preclude its use in practice. Efforts to improve accessibility to MRE in a timely fashion have the potential to further reduce radiation exposure in patients who require serial imaging related to this chronic disease.