Rotation and torsion of the left ventricle with cardiovascular magnetic resonance tagging: comparison of two analysis software

Background Left ventricle rotation and torsion are fundamental components of myocardial function, several software have been developed for the analysis of these components. Purpose of the study was to compare the suitability of two such software with different technical principles in analyzing rotation and torsion of the left ventricle during systole. Methods A group of hypertrophic cardiomyopathy (HCM) patients (N = 14, age 43 ± 11 years), mutation carriers without hypertrophy (N = 10, age 34 ± 13 years) and healthy controls (N = 12, age 43 ± 17 years) underwent a cardiovascular magnetic resonance examination including spatial modulation of magnetization tagging sequences in basal and apical levels of the left ventricle. The tagging images were analyzed offline using a harmonic phase image analysis method with Gabor filtering, and with non-rigid registration based free-form deformation technique. Left-ventricle rotation and torsion scores were obtained from end-diastole to end-systole with both software.Results Analysis was successful in all cases with both software. End-systolic torsion values between the study groups were not statistically different, with either software. End-systolic apical rotation, end-systolic basal rotation, and end-systolic torsion were consistently higher in Segment compared to HPF (p < 0.0001). End-systolic rotation and torsion values had statistically significant correlations between the two software (p < 0.0001), most significant in the apical plane. Conclusions When comparing absolute values of rotation and torsion between different individuals, software specific reference values are required. Harmonic phase flow with Gabor filtering, and non-rigid registration-based analysis methods can both be used reliably in the analysis of systolic rotation and torsion patterns of the left ventricle.