The efficacy of pineapple juice as a negative oral contrast agent in magnetic resonance cholangiopancreatography

BACKGROUND: During magnetic resonance cholangiopancreatography (MRCP), the pancreatobiliary ducts can be obscured by the high-intensity signal from the stomach and duodenum. Pineapple juice may be an alternative to commercially available negative contrast agents, but has not been evaluated locally. OBJECTIVES: To evaluate the efficacy of a local, off-the-shelf pineapple juice preparation as a negative oral contrast agent for MRCP. METHOD: An observational, analytical study was conducted during January–December 2017. A 1.5 Tesla MRCP sequence was performed immediately before and after ingestion of 250 mL of a local, commercially-available pineapple juice preparation. Image evaluation was performed by two radiologists with independent, blind assessment of gastric/duodenal signal intensity and biliary /pancreatic duct visibility, before and after pineapple juice. RESULTS: Fifty adult patients (F = 44, 88%) with median age 44 years (IQR: 34.75, 57) were included. After pineapple juice administration, there was significant measured (1661.51 vs. 1409.94, p < 0.01) and perceived (2.16 vs. 2.72, p < 0.01) duodenal signal reduction but no significant change in measured (1081.17 vs. 1044.38, p = 0.34) or perceived (2.73 vs. 2.84, p = 0.14) gastric signal intensity. Visibility of the common bile duct was significantly improved (3.67 vs. 3.86, p < 0.01), whilst that of the main pancreatic duct showed no significant change (2.92 vs. 2.86, p = 0.44). CONCLUSION: The local pineapple juice preparation used in this study is an effective, affordable and natural negative oral contrast agent for enhancement of MRCP images, and specifically improves visualisation of the common bile duct.