Figure 1.

Different parametric imaging in 3-/4D display, all from a normal subject. Left to right: The red-blue display of tissue velocity, the coloured bands of tissue tracking and the yellow-blue display of strain rate. In tissue velocity, lighter colour represents higher velocities, showing clearly the velocity gradient from base to apex both in systole and diastole. In tissue tracking, each colour represents an interval of 2 mm displacement, as shown by the legend. This means that red represents 2 – 4 mm displacement, increasing to magenta showing >14 mm at the base. Strain rate shows shortening in yellow to red, lengthening in blue, darker colour represents more deformation. Some inhomogeneity is visible due to noise and dropouts. Top to bottom: Bull's eye display both in systole and diastole (except tissue tracking), M-mode array from all six walls with apex on top and base at the bottom with ECG and a 3D surface reconstruction, velocity and strain rate in systole and diastole. The bull's eye projection shows all of the surface, but the area is distorted; the apex is progressively diminished, while the base is over-represented, the 3D figure shows a representation of the true area, but has to be rotated to se all of the surface. Reconstruction is done from three separate cine-loops, synchronised by means of ECG. The ECG at the left is inverted, but is from the same patient, as may be seen by the end of the cycle, where there is noise in the ECG signal. The aortic annulus and location of the imaging planes are added for orientation.