phase-contrast MRI
Also written as: PC-MRI — phase-contrast magnetic resonance imaging
A cardiac MRI technique that measures blood flow velocity and quantifies flow volumes through vessels and valves.
Full Definition
Phase-contrast MRI is a specialized cardiac magnetic resonance technique that exploits the phase shift of moving protons to measure blood flow velocities and calculate volumetric flow rates. The technique applies bipolar gradients that cause stationary tissue to remain unaffected while moving blood experiences a phase shift proportional to its velocity. This allows accurate quantification of flow through cardiac valves, great vessels, and bypass grafts, as well as assessment of regurgitant volumes and cardiac output. Phase-contrast imaging is particularly valuable for evaluating valvular disease, quantifying shunts, and measuring pressure gradients across stenotic lesions using the modified Bernoulli equation. The technique provides both velocity mapping and flow quantification in a single acquisition.
Usage
Usage note: PC-MRI is acceptable abbreviation; often hyphenated when used as adjective.
In Context
- "Phase-contrast MRI quantified the aortic regurgitation volume at 45 ml per beat." — Cardiac MRI report
- "PC-MRI through the ascending aorta confirmed reduced cardiac output in this heart failure patient." — Heart failure evaluation report