Unsupervised Computation of Left Ventricular Strain from Tagged Cardiac MR Images

Introduction: Cardiac MR tagging is a promising technique for non-invasively measuring the regional mechanical function (strain) in the left ventricular wall, but existing image analysis techniques require user supervised identification of myocardial contours in each image in the study (typically 200 images). These contours are used both in the tag tracking process to defme the region of interest and in the strain reconstruction process to define a coordinate system and model geometry tied to the specific heart under study. The purpose of this study is to develop an unsupervised technique for computing regional 3-D strain in the letI ventricular wall from tagged cardiac MR image data.