In-vivo motion analysis of bi-ventricular hearts from tagged MR images

Abstract

We conduct experiments to look at the in-vivo cardiac motion during systole, to visualize heart contraction, and to tamine the clinical usefulness. Our model-based technique incorporates subject-specific modeling, motion analysis and the extraction of clinically relevant parameters within one framework. Previous bi-ventricular model based method could only handle up to the mid-ventricles and have a few test-subjects. Our parameterized model includes the LV, RV and up to the basal area for full ventricular motion study. Finite element methods capture cardiac motion by tracking the material points from tagged Magnetic Resonance (MR) images. A number of experiments from ten subjects are evaluated and analyzed. We tested subject several times and compared the resulting parameters to ensure the reproducibility and deviations. The resulting parameters can be used to describe the cardiac motion of normal subjects. The patterns of normal subjects were derived from experiments. While significant shape and motion variations were apparent in normal subjects, the quantitative analysis show typical patterns. Generally, the basal area moves downwards and the apical area contracts towards the cavity. The principal strain analysis describes the directions and magnitudes of maximum shortening, and maximum thickening.