Continuous transmit focusing method and apparatus for ultrasound imaging system
View Patent ↗In one embodiment, an ultrasound imaging method comprises: providing a probe that includes one or more transducer elements for transmitting and receiving ultrasound waves; generating a sequence of spatially distinct transmit beams which differ in one or more of origin and angle; determining a transmit beam spacing substantially based upon a combination of actual and desired transmit beam characteristics, thereby achieving a faster echo acquisition rate compared to a transmit beam spacing based upon round-trip transmit-receive beam sampling requirements; storing coherent receive echo data, from two or more transmit beams of the spatially distinct transmit beams; combining coherent receive echo data from at least two or more transmit beams to achieve a substantially spatially invariant synthesized transmit focus at each echo location; and combining coherent receive echo data from each transmit firing to achieve dynamic receive focusing at each echo location.
1. An ultrasound imaging method for achieving transmit and receive focusing at every echo location within a region of interest, the method comprising:
providing a probe that includes one or more transducer elements for transmitting and receiving ultrasound waves;
generating a sequence of spatially distinct transmit beams which differ in one or more of origin and angle;
determining a transmit beam spacing based upon a combination of actual and desired transmit beam characteristics, the transmit beam spacing being determined without consideration of round-trip transmit-receive beam sampling requirements;
storing coherent receive echo data, from two or more transmit beams of the spatially distinct transmit beams;
combining coherent receive echo data from at least two or more transmit beams to achieve a spatially invariant synthesized transmit focus at each echo location; and
combining coherent receive echo data from each transmit firing to achieve dynamic receive focusing at each echo location.
2. The method of claim 1 , wherein the probe is a 1-D or 2-D array with varying degrees of elevation beamforming control, including aperture, delay, and phase, or a general 2-D scanning array, or a sparse 1-D or 2-D array.
3. The method of claim 1 , wherein the spatially distinct transmit beams are generated electronically, mechanically, or any combination thereof, to scan a 2-D plane or 3-D volume.
4. The method of claim 1 , wherein coherent receive echo data is receive channel data from different transducer elements.
5. The method of claim 1 , wherein combining coherent receive echo data from each transmit firing is performed prior to combining coherent receive echo data from at least two or more transmit beams.
6. The method of claim 5 , wherein combining coherent receive echo data from each transmit firing is performed prior to storing coherent receive echo data.
7. The method of claim 1 , wherein combining coherent receive echo data from each transmit firing is performed subsequent to combining coherent receive echo data from at least two or more transmit beams.
8. The method of claim 1 , wherein combining coherent receive echo data from each transmit firing and combining coherent receive echo data from at least two or more transmit beams are performed simultaneously.
9. The method of claim 1 , wherein combining coherent receive echo data from each transmit firing and combining coherent receive echo data from at least two or more transmit beams are performed at arbitrary echo locations or along multiple ray-like paths.
10. The method of claim 1 , wherein one or more non-linear components of the transmitted ultrasound waves are included in the steps of storing coherent receive echo data, combining coherent receive echo data from each transmit firing and combining coherent receive echo data from at least two or more transmit beams.
11. The method of claim 1 , further comprising forming an image with an imaging mode that includes one or more of B, color Doppler, power Doppler, M, spectral pulsed-wave Doppler, with or without using contrast agents.
12. The method of claim 11 , wherein velocity imaging modes including color velocity and spectral pulsed-wave Doppler are achieved using motion compensation in combining coherent receive echo data from at least two or more transmit beams.
13. The method of claim 11 , wherein the spectral pulsed-wave Doppler mode involves processing one or more sample volumes along an arbitrary path in 2-D or 3-D space.
14. The method of claim 1 , wherein combining coherent receive echo data from at least two or more transmit beams includes combining using one or more of delay, phase, amplitude, and convolution.
15. The method of claim 1 , wherein combining coherent receive echo data from at least two or more transmit beams is responsive to echo location, as well as to the spatial and temporal characteristics of the actual and/or desired transmit beam characteristics, which includes one or more non-linear components of the transmitted ultrasound waves.
16. The method of claim 15 , wherein combining coherent receive echo data from at least two or more transmit beams includes combining using one or more of delay, phase, amplitude, and convolution.
17. The method of claim 1 , wherein the spatially distinct transmit beams differ in one or more of delay, phase, apodization, amplitude, frequency, or coding.
18. The method of claim 1 , wherein the spatially distinct transmit beams have a single focus at a predetermined range, with an F-number ranging from 0.5 to 10.
19. The method of claim 1 , wherein two or more of the spatially distinct transmit beams are fired simultaneously, or with a time gap less than a round-trip propagation time, for an even faster echo acquisition.
20. An ultrasound imaging system for achieving transmit and receive focusing at every echo location within a region of interest, the system comprising:
a probe that includes one or more transducer elements for transmitting and receiving ultrasound waves;
means for generating a sequence of spatially distinct transmit beams which differ in one or more of origin and angle;
means for determining a transmit beam spacing based upon a combination of actual and desired transmit beam characteristics, the transmit beam spacing being determined without consideration of round-trip transmit-receive beam sampling requirements;
means for storing coherent receive echo data, from two or more transmit beams of the spatially distinct transmit beams;
means for combining coherent receive echo data from at least two or more transmit beams to achieve a spatially invariant synthesized transmit focus at each echo location; and
means for combining coherent receive echo data from each transmit firing to achieve dynamic receive focusing at each echo location.
21. An ultrasound imaging system for achieving transmit and receive focusing at every echo location within a region of interest, the system comprising:
a probe that includes one or more transducer elements for transmitting and receiving ultrasound waves; and
a processor configured to:
generate a sequence of spatially distinct transmit beams which differ in one or more of origin and angle;
determine a transmit beam spacing based upon a combination of actual and desired transmit beam characteristics, the transmit beam spacing based upon determined without consideration of round-trip transmit-receive beam sampling requirements;
store coherent receive echo data, from two or more transmit beams of the spatially distinct transmit beams;
combine coherent receive echo data from at least two or more transmit beams to achieve a spatially invariant synthesized transmit focus at each echo location; and
combine coherent receive echo data from each transmit firing to achieve dynamic receive focusing at each echo location.