Diagnostic imaging of hepatic lesions in adults.

Multiphase contrast-enhanced magnetic resonance imaging (MRI) is the current modality of choice for characterization of liver masses incidentally detected on imaging. Contrast-enhanced computed tomography (CT) performed in the portal phase is the mainstay for the screening of liver metastases. Characterization of a liver mass by CT and MRI primarily relies on the dynamic contrast-enhancement characteristics of the mass in multiple phases. Noninvasive MRI and CT imaging characteristics of benign and malignant liver masses, coupled with relevant clinical information, allow reliable characterization of most liver lesions. Some cases may have nonspecific or overlapping features that may present a diagnostic dilemma.