Figure 1
From: Regional assessment of left ventricular torsion by CMR tagging
A sketch of a basal and an apical plane and the torsional deformation. Twist is defined as (Φ apex - Φ base ), the twist per unit length as (Φ apex - Φ base ). ρ m /D and the torsion T (CL shear angle) as (Φ apex - Φ base ). ρm/D, with ρm the mean radius of the basal and apical level, in the undeformed and the deformed state. Counterclockwise rotation as seen from the apex is positive.