Diagnosis of liver diseases part 1: MRI of the liver. Clinical significance of nonspecific and liver-specific MRI contrast agents

The liver is a common site for various benign and malignant focal lesions. The initial modality for assessing liver lesions is ultrasound or CT. MRI with its superior soft tissue contrast offers multiple advantages over other imaging modalities. Contrast agents have been developed that increase the detection rate and provide more specific information in comparison to unenhanced techniques. In the mean time three classes are available for MR imaging of the liver: extracellular gadolinium chelates, hepatobiliary and reticulo-endothelia, superparamagnetic agents. We describe in this review the most common focal lesions, their diagnostic possibilities, and the imaging protocols. Clinical use of these contrast agents facilitates detection and differential diagnosis of focal liver lesions that may help to avoid invasive procedures such as biopsy for lesion characterization. (orig.)