Combined use of MR contrast agents for evaluating liver disease

The sequential administration of superparamagnetic iron oxide (SPIO) and extracellular gadolinium chelates combines the sensitivity of SPIO for lesion detection with the specificity of dynamic gadolinium-enhanced imaging for lesion characterization. This approach also may improve the detection of hypervascular lesion, because the different magnetic properties of SPIO and gadolinium produce a synergistic increase in contrast between the reduced signal intensity of background liver and the increased signal intensity of enhancing lesions. Despite the benefits, the additional cost and increased examination time of a combined contrast procedure requires the careful selection of patients. This article presents a brief overview of the different properties and the current status of SPIO and gadolinium for the diagnosis of focal liver lesions.