GB Cancer: Nonresectable - Main portal vein or hepatic artery - Right and left hepatic artery or portal vein within the liver - Concomitant ipsilateral hepatic artery and contralateral portal vein - Both lobes of the liver at confluence of hepatic ducts - > 2 contiguous segments in both lobes - Colon, duodenum, pancreas - Liver, peritoneal metastases
CT Technique: Indication Dependent 1. choledocholithiasis - Water PO; no IV or venous phase - thin reconstruction sections 2. cholangitis - Water PO, IV contrast, venous phase 3. cancer detection and staging - Water PO; IV contrast - dual phase arterial and venous
Historical Perspective - Oral and IV cholangiographic contrast agents - Contrast secreted into biliary tree - Decreased efficacy if bilirubin levels elevated - Risk of contrast reaction from an additional agent
