Three-dimensional flow-independent peripheral angiography

A magnetization-prepared sequence, T-2-Prep-IR, exploits T-1, T-2, and chemical shift differences to suppress background tissues relative to arterial blood, The resulting flow-independent angiograms depict vessels with any orientation and flow velocity, No extrinsic contrast agent is required, Muscle is the dominant source of background signal in normal volunteers. However, long-T-2 deep venous blood and nonvascular fluids such as edema also contribute background signal in some patients. Three sets of imaging parameters are described to address patient-specific contrast requirements, A rapid, spiral-based, three-dimensional readout is utilized to generate high-resolution angiograms of the lower extremities. Comparisons with x-ray angiography and two-dimensional time-of-flight angiography indicate that this flow-independent technique has unique capabilities to accurately depict stenoses and to visualize slow flow and in-plane vessels.