Abstract: An ultrasound system produces an image including a blood vessel. A blood flow direction indicator is displayed over the blood vessel to indicate the direction of blood flow within the vessel. The direction of blood flow is used to correct the Doppler estimate for angle of insonation. The orientation of the blood flow direction indicator is set automatically by a vector processor. The automatically calculated angle is used to display the correct flow velocity without user intervention.

Abstract: An ultrasonic diagnostic imaging system and method are described by which a fundamental frequency signal is transmitted into the body and harmonic (nonlinear) echo returns are received from the transmission. The harmonic echo signals are Doppler processed and displayed. The harmonic Doppler signals may be displayed alone, or in combination with a fundamental frequency or harmonic grayscale image. In a preferred embodiment harmonic signals returned from moving tissue are segmented on an intensity or frequency basis and displayed. The inventive apparatus and method provide highly resolved ultrasonic images of moving tissue which are substantially unobscured by image clutter from structures or tissue in the near field.