Multi-dimensional real-time ultrasonic blood flow imaging apparatus and method

An improved ultrasonic blood flow imaging apparatus comprising ultrasonic transducer means adapted to repeatedly transmit ultrasonic pulse beams into a subject under examination and to receive reflected echoes of the ultrasonic pulse beams from within the subject and convert the reflected echoes into echo signals, signal processing means for converting said reflected echo signals via Doppler signal processing into image signals, and display means for visually outputting said image signals as an image, the improvement comprising:

• (a) ultrasonic transducer means comprising a phased array transducer divided into two or more independently controlled sub-apertures and adapted for transmitting ultrasonic pulse beams from at least one of said two or more sub-apertures and for receiving the reflected echoes with at least two of said two or more sub-apertures, such that at least one sub-aperture is receiving an echo from a pulse beam that the at least one sub-aperture did not transmit;
• and
• (b) signal processing means including quadrature detection circuitry comprising sampling means for sampling said echo signals or a downward shifted version of said echo signals and Hilbert transform means for filtering said signals;
• whereby real time multi-dimensional blood flow imaging with enhanced sensitivity to lateral flow is achieved.

In a method for improved ultrasonic blood flow imaging comprising utilizing a phased array transducer for repeatedly transmitting ultrasonic pulse beams into a subject under examination, receiving reflected echoes of the ultrasonic pulse beams from within the subject and converting the reflected echoes into echo signals;

• utilizing signal processing means for converting said reflected echo signals via Doppler signal processing into image signals;
• and utilizing display means for visually outputting said image signals as an image, the improvement comprising:
• (a) electronically dividing said phased array transducer into two or more independently controlled sub-apertures;
• and
• (b) transmitting ultrasonic pulse beams from at least one of said two or more sub-apertures and receiving the reflected echoes with at least two of said two or more sub-apertures, such that at least one sub-aperture is receiving an echo from a pulse beam that the at least one sub-aperture did not transmit;
• whereby real time multi-dimensional blood flow imaging with enhanced sensitivity to lateral blood flow is achieved.

In a method for improved ultrasonic blood flow imaging comprising utilizing a phased array transducer for repeatedly transmitting ultrasonic pulse beams into a subject under examination, receiving reflected echoes of the ultrasonic pulse beams from within the subject and converting the reflected echoes into echo signals;

• utilizing signal processing means for converting said reflected echo signals via Doppler signal processing into image signals;
• and utilizing display means for visually outputting said image signals as an image, the improvement comprising:
• (a) electronically dividing said phased array transducer into two or more independently controlled sub-apertures;
• (b) transmitting ultrasonic pulse beams from at least one of said two or more sub-apertures and receiving the reflected echoes with at least two of said two or more sub-apertures, such that at least one sub-aperture is receiving an echo from a pulse beam that the at least one sub-aperture did not transmit;
• and
• (c) providing quadrature detection circuitry within said signal processing means for sampling said echo signals or a downward shifted version of said echo signals and filtering the samples of said signals with Hilbert transformations;
• whereby real time multi-dimensional blood flow imaging with enhanced sensitivity to lateral blood flow is achieved.