In a diagnostic scanner for shear wave elastography imaging an ultrasound exposure safety processoris is configured for spatially relating respective definitions of an imaging zone (324), and an extended dead-tissue zone (312) that includes both a dead-tissue zone and a surrounding margin. Based on whether a push pulse focus (344, 348, 352) is to be within the extended dead-tissue zone, the processor automatically decides as to a level of acoustic power with which the pulse is to be produced. If it is to be within, the pulse may be produced with a mechanical index, a thermal index, and/or a spatial-peak-temporal-average intensity that exceeds respectively 1.9, 6.0 and 720 milliwatts per square centimeter. The imaging zone may be definable interactively so as to dynamically trigger the deciding and the producing, with optimal push pulse settings being dynamically derived automatically, without the need for user intervention. A display of multiple push pulse sites (344-352) allows user manipulation of spatial definition indicia (336) to dynamically control displacement tracking.
