Ultrasonic imaging system and blood flow imaging method

An ultrasound blood flow imaging method, comprising:

• exciting a probe by a transmitting circuit to transmit divergent ultrasound beams corresponding to a virtual focus to a to-be-scanned region of a scan target that is covered by a scanning area of the divergent ultrasound beams;
• receiving echoes of the divergent ultrasound beams by the probe to obtain first electric signals, receiving the first electric signals by a receiving circuit, and performing beam synthesis on the first electric signals by a beamformer to obtain a group of divergent ultrasonic echo signals;
• calculating a direction and magnitude of a velocity of a target point in the to-be-scanned region of the scan target by a processor based on the group of divergent ultrasonic echo signals to generate a blood flow velocity vector information of the target point in the to-be-scanned region;
• and
• displaying the blood flow velocity vector information of the target point in the to-be-scanned region on a display,
• wherein a plurality of transducers of the probe are excited with a first group of transmission time delays to transmit ultrasonic waves to the scan target to form the divergent ultrasound beams, wherein an ultrasonic wave transmitted by a transducer closer to the virtual focus is transmitted earlier than an ultrasonic wave transmitted by a transducer far away from the virtual focus,
• wherein the divergent ultrasound beams comprise first divergent ultrasound beams and second divergent ultrasound beams that are transmitted in different ultrasonic waves propagation directions, and the target point in the to-be-scanned region is located in a scanning area scanned by both the first divergent ultrasound beams and the second divergent ultrasound beams,
• wherein the scanning area scanned by both the first divergent ultrasound beams and the second divergent ultrasound beams is a substantially trapezoidal scanning area that covers the to-be-scanned region of the scan target, and a size of the substantially trapezoidal scanning area in a position away from a plane on which the plurality of transducers are arranged is larger than a size of the substantially trapezoidal scanning area in a position close to the plane on which the plurality of transducers are arranged.

An ultrasound imaging system, comprising:

• a probe, comprising a plurality of transducers and configured to transmit divergent ultrasound beams corresponding to a virtual focus and receive echoes of the divergent ultrasound beams to obtain first electric signals;
• a transmitting circuit, configured to excite the probe to transmit the divergent ultrasound beams to a scan target to scan the scan target, wherein an ultrasonic wave transmitted by a transducer closer to the virtual focus is transmitted earlier than an ultrasonic wave transmitted by a transducer far away from the virtual focus;
• a receiving circuit and a beamformer, configured to receive and process the first electric signals to obtain divergent ultrasonic echo signals;
• a processor, configured to obtain a blood flow velocity vector information of the scan target according to the divergent ultrasonic echo signals;
• and
• a display, configured to display the blood flow velocity vector information of the scan target,
• wherein the transmitting circuit is further configured to excite the probe to transmit a plurality of divergent ultrasound beams having different virtual focuses to the scan target;
• the receiving circuit and the beamformer are further configured to obtain multiple groups of divergent ultrasonic echo signals based on the corresponding divergent ultrasound beams having different virtual focuses;
• and
• the processor is further configured to obtain a plurality of velocity components according to the multiple groups of divergent ultrasonic echo signals and synthesize the plurality of velocity components to obtain the blood flow velocity vector information of the scan target,
• wherein a scanning area scanned by the plurality of divergent ultrasound beams having different virtual focuses is a substantially trapezoidal scanning area, and a size of the substantially trapezoidal scanning area in a position away from a plane on which the plurality of transducers are arranged is larger than a size of the substantially trapezoidal scanning area in a position close to the plane on which the plurality of transducers are arranged.