Improved strain measuring using fast strain-encoded cardiac MR

The strain encoding (SENC) technique encodes regional strain of the heart into the acquired MR images and produces two images with two different tunings so that longitudinal strain, on the short-axis view, or circumferential strain on the long-axis view, are measured. Interleaving acquisition is used to shorten the acquisition time of the two tuned images by 50%, but it suffers from errors in the strain calculations due to inter-tunings motion of the heart, which is the motion between two successive acquisitions. In this work, a method is proposed to correct for the inter-tunings motion by estimating the motion induced shift in the spatial frequency of the encoding pattern, which depends on the strain rate. Numerical data is generated to test the proposed method and real images of human subjects are used for validation The results show an improvement in strain calculations so as to relax the imaging constraints on spatial and temporal resolutions and improve image quality.