Figure 3

Example of longitudinal tissue velocity evaluation from a myocardial PC dataset. Top: detection of the myocardial cluster on a velocity-encoded image (b) using the k-means map (c), after manual drawing of a rough region of interest around the myocardium. The contours corresponding to the calculated myocardial cluster were superimposed on each cardiac phase, and shown on few selected phases (d) (see additional file 2: myocardiumVideo, video file corresponding to the whole cardiac cycle). Of note, the modulus image corresponding to the phase image (b) was shown (a) to highlight the difficulty of segmenting such images. Bottom: extraction of early peak diastolic longitudinal velocity (E'_MR).