MRCP: Magnetic Resonance Cholangiopancreatography Explained
Magnetic resonance cholangiopancreatography maps the bile and pancreatic ducts without contrast, catheters or radiation, giving a non-invasive look before deciding on ERCP.
How it works
MRCP uses heavily T2-weighted sequences in which static fluid (bile, pancreatic juice) is very bright while surrounding tissue is dark. The result is a cholangiogram-like image of the ductal tree, reconstructed in 2D and 3D. No injected contrast is needed.
When it is used
- Choledocholithiasis: detecting common-bile-duct stones before intervention.
- Strictures: characterising benign vs malignant biliary strictures and their level.
- Pancreaticobiliary anatomy: variants, pancreas divisum, and planning before surgery/ERCP.
- PSC and duct disease: the beaded duct pattern of primary sclerosing cholangitis.
- Pancreatic duct: chronic pancreatitis, IPMN communication with the duct.
MRCP vs ERCP
MRCP is diagnostic and non-invasive; ERCP is therapeutic (stone removal, stenting) but carries risks including pancreatitis. The modern pattern is MRCP first to decide who genuinely needs a therapeutic ERCP, avoiding diagnostic-only ERCPs. Secretin-enhanced MRCP can improve pancreatic-duct assessment.
Sources
- Griffin N et al. Magnetic resonance cholangiopancreatography: the ABC of MRCP. Insights Imaging 2012;3:11–21.
Educational summary for clinicians; local pathways take precedence. Not medical advice.