The trisodium salt form of gadofosveset, an injectable, intravascular, amphiphilic gadolinium-based contrast agent (GBCA) used with magnetic resonance angiography (MRA) imaging. Gadofosveset is a stable gadolinium diethylenet triaminepentaacetic acid (Gd-DTPA) chelate derivative with a diphenylcyclohe xylphosphate group. Upon injection, gadofosveset binds reversibly to endogenous serum albumin which increases its intravascular retention time compared to non-protein binding contrast agents. The serum albumin binding also increases T1-relaxivity of gadofosveset. This produces an increase in signal intensity of blood, thereby enhancing the visualization of blood vessels upon MRA and may aid in the diagnosis of certain blood vessels and heart disorders.