Correction of left ventricle strain signals estimated from tagged MR images

Strain measurement is a quantity used for assessing the regional function of the left ventricular (LV) of the heart. They are computed by tracking the motion of the non-invasive, virtual tags in the cardiac muscle with time. Tracking these tags gives information for each region of the cardiac muscle by quantifying its deformation during contraction (systolic period) and relaxation (diastolic period). However, these strain measurements suffer from inaccuracies caused by the degradation of the tags and the image quality. In this work, numerical simulations are used to investigate the factors contributing to the error in measurements. An empirical model for the estimated strain values is deduced and presented. In addition, a correction method for the measurement errors is proposed based on the empirically-deduced model. The method was validated on real data, and showed potential enhancement by reducing the errors in strain measurements. © Springer-Verlag Berlin Heidelberg 2010.