Does secretin stimulation add to magnetic resonance cholangiopancreatography in characterising pancreatic cystic lesions as side-branch intraductal papillary mucinous neoplasm?

Objectives: To assess the value of secretin during magnetic resonance cholangiopancreatography (MRCP) in demonstrating communication between cystic lesions and the pancreatic duct to help determine the diagnosis of side-branch intraductal papillary mucinous neoplasm (SB-IPMN).

Methods: This is an IRB-approved, HIPAA-compliant retrospective study of 29 SB-IPMN patients and 13 non-IPMN subjects (control) who underwent secretin-enhanced MRCP (s-MRCP). Two readers blinded to the final diagnosis reviewed three randomised image sets: (1) pre-secretin HASTE, (2) dynamic s-MRCP and (3) post-secretin HASTE. Logistic regression, generalised linear models and ROC analyses were used to compare pre- and post-secretin results.

Results: There was no significant difference in median scores for the pre-secretin [reader 1: 1; reader 2: 2 (range -2 to 2)] and post-secretin HASTE [reader 1: 1; reader 2: 1 (range -2 to 2)] in the SB-IPMN group (P = 0.14), while the scores were lower for s-MRCP [reader 1: 0.5 (range -2 to 2); reader 2: 0 (range -1 to 2); P = 0.016]. There was no significant difference in mean maximum diameter of SB-IPMN on pre- and post-secretin HASTE, and s-MRCP (P > 0.05).

Conclusion: Secretin stimulation did not add to MRCP in characterising pancreatic cystic lesions as SB-IPMN.

Key Points: Magnetic resonance cholangiopancreatography (MRCP) is used to evaluate pancreatic cystic lesions. Intraductal papillary mucinous neoplasm (IPMN) is a type of pancreatic cystic neoplasm. Secretin administration does not facilitate the diagnosis of IPMN on MRCP.