The Effect of Through Plane Motion on Left Ventricular Regional Rotation: A Study using Slice-Following Harmonic Phase (SF-HARP) Imaging.

David Brotman¹, Ziheng Zhang², Smita Sampath²

Recent studies reveal that regional rotation may be primarily responsible for the creation of suction enabling normal diastolic filling, and may serve as an early diagnostic indicator of diastolic dysfunction. Here, we highlight the importance of taking into account through-plane motion when calculating regional rotation. We employ a combination of slice-following tagged MRI and harmonic phase tracking (SF-HARP) to compute true two dimensional trajectories of myocardial material points, from which rotation is computed. Our results (rotation curves, and rotation-circumferential shortening loops) show differences in the computed rotation values in comparison to conventional tagging. In conclusion, SF-HARP provides reliable and accurate quantification of regional rotation in the left ventricle.