Spatio-temporal tracking of myocardial deformations with a 4-D B-spline model from tagged MRI

Accurate delineation of the volumetric motion of the left ventricle (LV) of the heart from tagged magnetic resonance imaging (MRI) is an important are a of research. We have built a system that takes extracted tag line feature s from short axis (SA) and long axis (LA) image sequences as input and fits a four-dimensional (4-D) time-varying B-spline model to the data by simult aneously fitting the model knot solids to MRI frames via matching three seq uences of solid knot planes to the LV tag planes for 4-D tracking. Importan t advantages of the model are that reconstruction of tag surfaces, three-di mensional (3-D) material point localization, as well as displacement recons truction are all achieved in a single step. The generated 3-D displacement fields are validated with a cardiac motion simulator, and 3-D motion fields capturing in vivo deformations in a porcine model with posterolateral myoc ardial infarction are illustrated.