Cardiac strain and rotation analysis using multi-scale optical flow

Tagging MRI enables analysis of the local contractility of the cardiac leftventricle. It permits reliable assessment of local contractile dysfunction related tovarious cardiomyopathies. We present a multi-scale optical flow method, with Gaborfiltering, 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 constraintequation 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 oneischemic patient case with known wall motion abnormalities, and two volunteers.Patient circumferential strain abnormalities colocalize with enhanced areas in lateenhancementMRI. Rotation patterns are presented for the same patient and fourvolunteers. The rotation pattern described in the patient is strikingly different fromthat describing the volunteers