Gadofosveset trisodium is an intravenous contrast agent used with magnetic resonance angiography (MRA), which is a non-invasive way of imaging blood vessels. The agent allows for the vascular system to be imaged more clearly by the MRA. In this way, gadofosveset trisodium is used to help diagnose certain disorders of the heart and blood vessels. Gadofosveset binds reversibly to endogenous serum albumin resulting in longer vascular residence time than non-protein binding contrast agents. The binding to serum albumin also increases the magnetic resonance relaxivity of gadofosveset and decreases the relaxation time (Tl) of water protons resulting in an increase in signal intensity (brightness) of blood. The extended acquisition time and increased relaxivity of gadofosveset allows for longer steady-state acquisition times, and potentially submillimeter voxels. Overlay of veins in steady-state MR angiography is less of a problem in multiplanar reformats with this level of resolution. This is particularly promising for MR evaluation of the peripheral vasculature. In the United States, gadofosveset is FDA-approved only for use in aortoiliac disease, with other uses being off-label. It currently does not have a role in hepatic imaging.