Fig. 1

4D-flow cardiovascular magnetic resonance (CMR) imaging analysis. Step 1: planning of multiple, gapless short-axis slices covering the left ventricular (LV) outflow tract (LVOT) (upper red panels) and mitral valve (MV) (lower blue panels) through the entire cardiac cycle. Note the apical excursion of annular planes during systole (*). A and B cine-guided LVOT and mitral valve segmentation (upper panels) with corresponding interpolated 4D phase-contrast (PC) data (lower panels). Step 2: three-dimensional pathlines visualization emitted from LVOT and mitral valve planes superimposed on long-axis cines. Step 3: four-dimensional quantitative flow analysis and use of standard CMR indirect method for cross-checking (Step 4). An additional movie file shows this in more detail [see Additional file 2]. LVOT left ventricle outflow tract, MV mitral valve, SV stroke volume, RVol and RF regurgitant volume and fraction