MRA is a type of magnetic resonance imaging (MRI) in which blood appears bright. To form a magnetic resonance (MR) angiogram, a 3-dimensional set of thin sections is acquired through the region of interest. The images are then processed by computer to create a 2-dimensional projected display that resembles a conventional angiogram. There are many ways to cause blood to appear bright on MRI. Each of these mechanisms corresponds to a different type of MRA. Brightness may result from the entry of blood into the section. This mechanism is responsible for the time-of-flight (TOF) methods.1 Brightness may be dependent on the velocity of blood, which is the principle behind phase-contrast (PC) MRA.2 Brightness may result from the injection of contrast agents, which is the basis for contrast-enhanced MRA (CEMRA).3 Other mechanisms exist as well, although they are much less common than these three. In recent years, CEMRA has emerged as the dominant MRA method. CEMRA is applicable to nearly every abdominal vessel, including the aorta, renal arteries, mesenteric arteries, and portal vein.4 CEMRA is much faster than TOF and PC. It is accomplished in a single breath hold and so is less exhausting to the patient, as compared with TOF, which may require a separate breath hold for each section. CEMRA is demonstrably better than TOF or PC in the imaging of arterial branch vessels. Furthermore, it resembles conventional angiography and CT angiography (CTA), both of which use the same principle of blood enhancement by intravascular contrast agents.