MRkolecystografi

MR kolecystografija, or magnetic resonance cholangiography (MRCP), is a noninvasive MRI technique designed to visualize the biliary tree and adjacent pancreatic ducts. It relies on heavily T2-weighted imaging to render the bile-filled ducts as bright structures, enabling a noninvasive cholangiogram without iodinated contrast. In some protocols, hepatobiliary contrast agents (such as gadoxetate disodium) or secretin can be used to enhance ductal visualization or distend the ducts for improved assessment.

The examination typically involves patient fasting and imaging with 3D heavily T2-weighted sequences, sometimes complemented by breath-hold or navigator-triggered acquisitions. When contrast-enhanced MRCP is used, images are acquired during the hepatobiliary phase to highlight bile excretion into the ducts. The study assesses the anatomy from the intrahepatic ducts to the ampulla, identifying obstructions, stones, strictures, anomalies, or postoperative changes.

Indications include evaluation of biliary obstruction (e.g., choledocholithiasis, strictures, tumors), congenital biliary or pancreatic ductal anomalies, preoperative planning for biliary or hepatic surgery, assessment after cholecystectomy in persistent symptoms, and pediatric evaluation of suspected biliary atresia or other malformations. MRCP is often used to triage patients prior to invasive procedures.

Advantages include its noninvasiveness, absence of ionizing radiation, and ability to provide detailed biliary anatomy. Limitations are reduced sensitivity for very small stones, motion artifacts, and inability to perform therapeutic intervention; if intervention is required, ERCP or percutaneous cholangiography may be employed. Safety considerations include avoidance of gadolinium in certain renal impairments and standard MRI contraindications.