The potential impact of high-quality MRI of the biliary tree on ERCP workload.

BACKGROUND

Magnetic resonance cholangiography (MRC) is a non-invasive method of imaging the biliary tree with virtually no morbidity. Endoscopic retrograde cholangiopancreatography (ERCP) has a significant morbidity, mortality and failed imaging rate. Unlike MRC, ERCP is highly dependent on the clinical team for high-quality results and minimal morbidity. MRC requires high-quality image acquisition and appropriate reconstructions, with skilled reading of the images.

OBJECTIVES

To assess the impact on ERCP workload of using MRC as the initial imaging modality for the biliary tree in selected patient groups, and to assess procedure-related morbidity and mortality.

METHODS

An analysis of 1078 consecutive ERCP examinations performed at our institution over the six years to 1996 has been undertaken. Complications, imaging failure rates and ERCP findings have been analysed in the different referral categories to assess the potential impact of MRC on future ERCP workload and patient outcomes.

RESULTS

At our institution, if MRC had been used as the first imaging investigation in patients with abdominal pain (n = 336, with or without abnormal liver function tests but without clinical jaundice) and those with present or past acute pancreatitis (n = 101), we estimate that 83 (19%) would have needed to go on to ERCP, but 354 (81%) would not have required further invasive investigation. In these categories, this would have resulted in five patients with stones missed at MRC, but 14 extra patients with stones would have been identified whose stones would have been missed at ERCP (failed examinations). There would be an overall 33% reduction in ERCP workload and 20 serious complications related to ERCP would have been avoided. Overall 7% of patients would be subjected to both investigations.

CONCLUSIONS

In the interests of efficient use of resources, minimization of patient complications and accurate identification of those requiring therapeutic ERCP, MRC should be the preferred initial investigation in selected groups of patients presently being subjected to ERCP.