Performance of myocardial velocity quantification method. A) The peak error was calculated as the relative difference between the true and estimated velocities. B) Peak timing error was the time difference between the true peak position and the estimated peak position. The theoretical limit (dotted line) is half the inverse of frame rate and is the upper limit for the non-interpolated timing error. C) Comparison of performance between the proposed method and 2-D speckle tracking method in mild “best case” conditions (no lateral or out-of-plane motion, and only axial displacement of tissue). D) Same as in C but in rough “worst case” conditions (including axial deformation, and out-of-plane motion).