The revolution in imaging techniques over the past few years has created a bewildering array of choices for clinicians investigating patients with suspected hepatic disease. In particular, advances in ultrasound (US), CT scan, and MR imaging have led to improved detection and characterization of liver lesions such that a definitive diagnosis can often be achieved noninvasively. Clinical information, however, is of paramount importance in selecting the appropriate imaging modality and interpreting the study accurately. The powerful combination of radiologic findings and clinical information enables the radiologist to categorize a hepatic lesion according to whether surgical management is necessary. Nonsurgical entities are lesions that, if correctly characterized by imaging, require no further attention (e.g., hemangioma; abscess, cyst; focal nodular hyperplasia; diffuse liver diseases, such as hemochromatosis and cirrhosis; and normal variants, such as focal fatty liver). Examples of surgical diagnoses include hepatocellular carcinoma, adenoma, and metastases in patients undergoing evaluation for hepatic resection. Recent developments in imaging, such as chemical shift techniques and MR imaging contrast agents, enable the radiologist confidently to categorize many lesions as nonsurgical, thereby obviating the need for interventional techniques, such as percutaneous biopsy, which have an associated morbidity. Within the surgical group, imaging plays a key role in identifying disease extent, which has important prognostic and therapeutic implications. For example, the number and size of hepatic metastases from colorectal neoplasms as well as the presence of extrahepatic disease are major determinants of long-term survival in patients undergoing hepatic resection.<sup>1 Baker M.E., Pelley R. Hepatic metastases: Basic principles and implications for radiologists Radiology 1995 ;  197 : 329-337

Cliccare qui per andare alla sezione Riferimenti, 46 Sugarbaker P.H. Surgical decision making for large bowel cancer metastatic to the liver Radiology 1990 ;  174 : 621-626

Cliccare qui per andare alla sezione Riferimenti</sup> Accurate preoperative evaluation of tumor burden by imaging techniques is therefore a central issue in the assessment of these patients. Clearly, radiologists are now in a unique position to influence directly the management of patients with liver lesions provided that the relevant technology and clinical information are available. We review the importance of clinical information in the interpretation of imaging studies, emphasize the impact on patient management of cross-sectional imaging techniques, and provide an overview of recent advances in US, CT scan, MR imaging, and scintigraphy, which are elaborated elsewhere in this issue.