Time-of-flight MR angiography.

Time-of-flight effects depend on the displacement of blood with respect to a region of excitation. When combined with static material suppression and projection imaging, time-of-flight effects provide a flexible means of flow sensitization for magnetic resonance (MR) angiography. Bolus tracking, flow enhancement by spin replacement, and selective tagging are three classes of methods being pursued for MR angiography.