Measurement of 3D motion of myocardial material points from explicit b-surface reconstruction of tagged MRI data

Abstract

MRI is unique in its ability to non-invasively and selectively alter tissue magnetization, and create tag planes intersecting image slices. The resulting grid of signal voids allows for tracking deformations of tissues in otherwise homogeneous-signal myocardial regions. In this paper, we propose a specific Spatial Modulation of Magnetization (SPAMM) imaging protocol together with efficient techniques for measurement of 3D motion of material points of the human heart from images collected with the SPAMM method. The techniques make use of tagged images in orthogonal views by explicitly reconstructing 3D B-spline surface representation of each tag plane (two intersecting the short-axis (SA) image slices and one intersecting the long-axis (LA) image slices). The developed methods allow for viewing deformations of 3D tag surfaces, spatial correspondence of long-axis and short-axis image slice and tag positions, as well as non-rigid movement of myocardial material points as a function of time.