A method for ultrasound imaging of anatomical tissue. A first signal is received from a first imaging ultrasound wave which has been reflected from a location in the anatomical tissue during a first time period. A second signal is received from a second imaging ultrasound wave which has been reflected from the location in the anatomical tissue during a later second time period, following a discrete medical treatment. The second signal is subtracted from the first signal to form a difference signal. The difference signal may be scaled, spatially filtered, then used to generate an indication, the indication showing the effect of the medical treatment in the location in the anatomical tissue.