Duplex ultrasonic imaging system with repetitive excitation of common transducer in Doppler modality

摘要

A duplex imaging system with a common transducer array (11) for both modes of operation satisfies the conflicting bandwidth requirements by single impulse excitation of the transducer (12) in B-scan imaging operation to generate a wide bandwidth ultrasound pulse and multiple impulse excitation at the emission frequency in Doppler mode operation to generate a narrow bandwidth ultrasound pulse. The multiple impulse excitation has a variable repetition frequency depending on range to a sample volume and velocity of blood flow. A Doppler modality in which the frequency shift of echoes caused by flow of blood is measured to derive the flow velocity, is incorporated into a sector scanner with little additional complexity.