Three dimensional analysis of cardiac shape and load using tagged magnetic resonance imaging

Three dimensional (3D) reconstructions of the heart from sets of two dimensional (2D) tagged magnetic resonance imaging (MRI) cross sections, were used to characterize the 3D geometry of the left ventricles in patients with hypertrophic cardiomyopathy (HCM) and patients with right ventricular pressure overload (RVPO). Curvatures, stresses, wall thickness and endocardial motion were calculated from surface and volume elements. Hearts with RVPO exhibited more circumferential and meridional flattening of the septum than normal and HCM hearts. The stress indices were lowest in the HCM hearts, compared to normal and RVPO hearts, due to the larger thicknesses. There was a more significant difference between lateral wall motion, and other regional wall motions in the HCM and RVPO hearts as compared to normal hearts. It is suggested that curvature and stress mapping by 3D tagged MRI can be advantageously used as an important clinical tool.<
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