[Diagnostic radiology of liver tumors. Part 1: General disease aspects and radiological procedures].

Besides malignant disease, focal liver lesions can also represent benign changes. Among the malignant lesions, in addition to hepatocellular carcinoma, liver metastases should be mentioned. In contrast, benign lesions such as focal nodular hyperplasia and hepatocellular adenoma are rarely encountered. Various radiological procedures are employed for the (differential) diagnosis. The transabdominal ultrasound examination is supplemented by color Doppler procedures, contrast-enhanced or intraoperative ultrasound. Computed tomography (CT) should be performed with native images as well as after using modern nonionic, iodine-containing water-soluble contrast agents; multidetector spiral CT is today's standard. If comparable optimal technology is available on-site, (contrast-enhanced) MRI is preferable. Intra-arterial selective angiography has become less important for detecting and characterizing focal liver changes with the advent of tomographic procedures. The question of whether sonography- or CT-guided biopsy of the liver is needed for further diagnostic work-up, whether a wait-and-see approach is justified, or whether surgery is required to clarify the diagnosis should always be answered on a case-by-case basis.