Introduction MRCP is a standard investigation in pancreato-biliary disease. Secretin-MRCP has been shown to have value in the investigation of suspected Sphincter of Oddi dysfunction (SOD). We have used this modality since 2005 and review here the clinical utility of secretin-MRCP in our institution, with reference to indications, findings, and clinical outcomes.
Methods Patients undergoing secretin MRCP had a conventional MRCP, with determination of the best imaging plane for pancreatic and biliary ductal assessment. Secretin was then injected (1 U/Kg) and imaging was repeated every minute for 15 min, with documentation of ductal and exocrine responses. For this review, persistent ductal dilatation at 15 min was considered probable SOD and onset of pain after secretin possible SOD. All patients undergoing secretin-MRCP were identified from a radiology database. A casenote review was done, with documentation of indications and outcome measures as outlined above.
Results Seventy patients underwent secretin-MRCP between 2005 and 2011 (mean age 44, range 17-84, M:F ratio 3:1). Indications were; biliary pain with abnormal LFTs or ultrasound (suspected type 2 SOD, N=9), pain with normal investigations (suspected type 3 SOD, N=42), unexplained pancreatitis (N=13) or assessment of complicated pancreatitis (N=6). Forty-four scans were normal, 12 showed anatomical abnormalities and 14 probable/possible SOD (persistent ductal dilatation six, secretin-induced pain six, both two). Most (13/14) MRCP diagnoses of SOD were in patients where the clinical indication was biliary pain. In patients with SOD, 4/13 underwent ERCP with sphincterotomy and 9/13 were treated conservatively. In patients undergoing sphincterotomy, there were no procedural complications and all had relief of pain (two patients later solicited further ERCP and sphincterotomy).
Conclusion In this series, secretin-MRCP was valuable in a group of patients with suspected SOD. Most scan findings for this indication are normal, but in some patients an abnormal scan is valuable in giving a positive diagnosis. A subgroup of these may benefit from ERCP with sphincterotomy, while others respond adequately to conservative therapy.
Competing interests None declared.