Abstract: A method and apparatus for achieving ultrasonic coronary thrombolysis. After intravenous injection of a thrombus-specific ultrasound contrast agent, an array of ultrasonic transducers arranged in a pad placed on the patient's chest transmits ultrasound signals into the patient, from a virtual source. Reflected signals are then analyzed to determine the ratio of the second (or hall) harmonic to first harmonic components in the signals. A high ratio indicates the presence of a thrombus in the field of interrogation Time-of-flight data for each of the receivers is used to calculate a spatial location of the thrombus, and a phased array ultrasonic transmission is then focused on the thrombus, so as to achieve sonoparation.