Figure 2

Illustration of the prescription and measurements obtained from phase contrast MR. Two identical stacks of phase contrast images were prescribed on a 3 chamber view of the heart (i). To assess transmitral and aortic flow, a velocity encoding (venc) of 250 cm/s was used and the center of the slice was positioned perpendicular to mitral inflow, at early diastole (ii, upper panel). To assess tissue MR velocities, phase-contrast MR was repeated with a velocity encoding of 30 cm/s, (ii, lower panel) To derive aortic and trans-mitral flow (iii, top panel), circular regions of interest were placed in the aortic (green) and mitral valve (red). On the corresponding mitral flow curve (panel iii, red) the peak mitral velocity of rapid early (E) filling wave late atrial (A) filling wave were recorded. The deceleration time (DT) of the early (E) wave of the mitral valve was computed between the peak of the E wave and the point where the fitted line of descending slope of the E wave reached zero velocity. The isovolumic relaxation time (IVRT) was computed as the delay between the end of the aortic valve flow and the beginning of the transmitral flow. On the tissue velocity images (ii lower panel, regions of interest were placed on the septal (orange) and lateral wall (yellow) and corresponding tissue velocity versus time curves were plotted (iii lower panel). From these curves, peak tissue velocity in early diastole in the septum (e'_s) and lateral wall (e'_l) was measured and average E/e'ratio was computed.