Cardiac Strain and Rotation Analysis Using Multi-scale Optical Flow

Tagging MRI enables analysis of the local contractility of the cardiac left ventricle. It permits reliable assessment of local contractile dysfunction related to various cardiomyopathies. We present a multi-scale optical flow method, with Gabor filtering, for the extraction of dense motion fields from cardiac MR tagging. It is based on a multi-scale first order extension of the classical optical flow constraint equation enabling the extraction first order parameters like rotation and strain. A quantitative validation study based on the phantom proposed by Young et al. showed excellent performance. Furthermore, strain patterns are presented for one ischemic patient case with known wall motion abnormalities, and two volunteers. Patient circumferential strain abnormalities colocalize with enhanced areas in late-enhancement MRI. Rotation patterns are presented for the same patient and four volunteers. The rotation pattern described in the patient is strikingly different from that describing the volunteers.