Transvascular ultrasound hemodynamic catheter

An interventional catheter apparatus is disclosed. The catheter comprises an elongated body that has a longitudinal axis and a substantially cylindrical side that extends between a proximal end of the body and a distal end of the body. The body is of a size and flexibility so that its distal end can be guided through the vasculature of a subject and into an internal, fluid filled cavity. A linear phased array ultrasonic transducer (30) is mounted on the cylindrical side of the body near the distal end, and the ultrasonic transducer has transducer elements for transmitting ultrasonic signals and simultaneously receiving resultant ultrasound information, suitable for producing an image of the internal cavity in a field of view near the distal end of the elongated body and for simultaneously measuring flow rates in the field of view. An electrical conductor disposed in the catheter body is connected to the ultrasonic transducer and extends along the length of the catheter body to its proximal end for connection to a medical system.