Figure 2.

M-mode image of a valid event. The image contains 20 A-lines acquired with a PRF of 4 kHz. In this example, the excitation toneburst was a 20-cycle pulse with a peak-rarefactional pressure of 2.1 MPa. A-lines 8–14 contain echoes from the same agent. The valid event is symbolized by the dashed line. The solid lines symbolize the 400-rf points centered at the focus of the transducer.