Liver MRI with contrast enhancement.

Liver MR imaging has improved substantially in the last decade due to advances in equipment design and pharmaceutical development. Contrast agents for the liver have been examined within three major classes. Extracellular agents (Gd HP-DO3A, Gd DTPA, and Gd DTPA-BMA) are currently in widespread clinical use. Gadolinium chelates with hepatobiliary excretion are in clinical trials (Gd BOPTA and Gd EOB-DTPA). With respect to particulate agents, one (AMI-25) has received Food and Drug Administration (FDA) approval recently. Imaging technique is critical to proper use, with different strategies employed depending on the class of agent. With gadolinium chelates, T1-weighted images are used for visualization, with dynamic scans being important for extracellular agents, and both dynamic and delayed scans being important for agents with hepatobiliary excretion. With the particulate iron compounds, T2-weighted images are used for visualization, with emphasis on delayed imaging.