Methods for determining a mechanical parameter for a sample having a target region include generating a tissue displacement in the target region; transmitting tracking pulses in the target region; receiving corresponding echo signals for the tracking pulses in the target region at a plurality of positions; analyzing the echo signals at one or more multi-resolution pairs of the positions and/or acquisition times; and determining at least one mechanical parameter of the target region based on the echo signals at the one or more multi-resolution pairs of positions and/or acquisition times.