Visualizing myocardial function using HARP MRI.

Harmonic phase magnetic resonance imaging (HARP) is a new technique for measuring the motion of the left ventricle of the heart. HARP uses magnetic resonance tagging, Fourier filtering and special processing algorithms to calculate key indices of myocardial motion including Eulerian and Lagrangian strain. This paper presents several new methods for visualizing myocardial motion based on HARP. Quantities that are computed and visualized include motion grids, velocity fields, strain rates, pathlines, tracked Eulerian strain, and contraction angle. The computations are fast and fully automated and have the potential for clinical application.