Automated quantification of human left ventricular deformation with magnetic resonance cardiac tagging

A method was developed to quantify deformation of the human cardiac left ventricle (LV) non-invasively. The authors´ primary interest was LV torsion and contraction during the ejection phase, as these may be of clinical importance. Magnetic Resonance cardiac tagging was used in 9 healthy volunteers to determine displacement, rotation and contraction of two parallel short-axis cross-sections in the LV equatorial region. Rotation angles from these cross-sections were subtracted to quantify torsion. During ejection torsion increased by 5.3±1.2 degrees (mean±sd), and the inner and outer radii decreased from 24.5±1.7 mm to 16.8±1.8 mm, and from 35.7±2.9 mm to 31.8±2.6 mm, respectively. It can be concluded that the developed method provides a highly automated means for assessment of LV torsion and contraction in humans