CPC A61B 8/06 (2013.01) [A61B 8/52 (2013.01); A61B 8/488 (2013.01)] | 4 Claims |
1. An ultrafast Doppler ultrasound method for estimating a blood flow velocity through repetitive compounding of multi-angle plane waves, wherein the method comprises:
controlling an ultrasonic transducer to cyclically transmit plane waves according to a sequence of deflection angles of {0,−β,β,−β} to an area to be scanned;
receiving echo signals of the plane waves reflected by the area to be scanned, wherein the echo signals are obtained according to a basic cyclic unit of deflection angles arranged in a sequence of 0−β ß−ß;
searching for three consecutive frames of signals (as a frame group) with deflection angles in a sequence of {0,−β,β} and {β,−β,0} in the echo signals to obtain multiple frame groups, wherein, among the multiple frame groups, a last frame signal of a previous frame group of two adjacent frame groups is used as a start frame signal of a next frame group;
compounding the three consecutive frames of signals of each frame group to obtain a compounded radio frequency (RF) signal;
calculating a blood flow velocity according to the compounded RF signal; and
performing color coding on the blood flow velocity to generate a two-dimensional (2D) blood flow velocity image;
performing local registration on the three consecutive frames of signals of each frame group comprising subjecting the three consecutive frames of signals of each frame group to the following operations:
calculating a first offset of the start frame signal relative to an intermediate frame signal;
calculating a second offset of the last frame signal relative to the intermediate frame signal; and
performing local registration on the three consecutive frames of signals of each frame group according to the first offset and the second offset;
wherein a specific control process of the local registration is as follows: three consecutive frames of RF echo signals {RF0, RF−β, RFβ} or {RFβ, RF−β, RF0} with the deflection angles of {0,−β,β} or {β,−β,0} are divided into H×K (horizontally divided into H blocks, vertically divided into K blocks) local RF echo signals; offsets of
the local RF echo signals RF0((h,k) and RFβ(h,k) relative to RF−β(h,k) are calculated
respectively, and RF0((h,k) RFβ(h,k) and RF−β(h,k) are registered according to the offsets, where, 1≤h≤H, 1≤k≤K.
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