An illustration of the Septal Scout method. The Septal Scout monitors long-axis motion of the septum using projection imaging of a slice along the ventricular septum. (a) The 4-chamber long-axis view from which the Septal Scout is prescribed is shown. The dashed white rectangle shows the graphical prescription of the Scout Plane, which is perpendicular to the 4-chamber view and runs along the ventricular septum. (b) An image of the Scout Plane is shown here for illustration. The Septal Scout does not acquire this image, rather, it acquires much more quickly projections (in the AL-PR direction) of this image plane. (c) Successive Septal Scouts are displayed as vertical line images and appended along a horizontal time axis. An ROI (dotted black box) is chosen at a depth near the basal septum spanning one cardiac cycle. The image intensities in this ROI are processed using optical gradients to form a pseudo-velocity graph. (d) The pseudo-velocity graph is shown. The diastasis period is visible as a plateau region in between the early filling (E-wave) and atrial contraction (A-wave) cardiac phases.