Diagnostic imaging approaches and relationship to hepatobiliary cancer staging and therapy

Diagnostic imaging plays an essential role in management of hepatobiliary t umors. High resolution images provided by computed tomography (CT), magneti c resonance imaging (MRI), and ultrasound (US) allow detection of tumor wit hin the liver. CT arterial portography remains the standard for detection o f small lesions in the range of 1.5 cm, but noninvasive techniques such as contrast-enhanced helical CT and MR hold promise for comparable lesion dete ction. MRI provides lesion characterization for differentiation of benign a nd malignant tumors. Lesion characterization has been further improved by f aster CT and MR techniques that allow imaging in both arterial and portal v enous phases for characterization of lesions based on the rate and pattern of enhancement. Functional imaging such as 2-fluoro-2-deoxy-D-glucose-posit ron-emission tomography (FDG-PET) is increasingly utilized for detection of intrahepatic tumor and extrahepatic disease. Accuracy of FDG-PET for extra hepatic disease is better than conventional imaging and has been shown to c hange management in a significant number of patients. Imaging is also inval uable for surgical planning. Segmental anatomy is well shown by CT, MRI, an d US. CT or MR angiography with newer 3D techniques delineate vascular vari ants and areas of encasement or occlusion by tumor. Biliary involvement at the hilus may be shown by US and MR cholangiography. Imaging detection of v ascular involvement, bile duct extension, and lobar atrophy may alter the s urgical approach. Semin. Surg. Oncol. 19:94-115, 2000. (C) 2000 Wiley-Liss, Inc.