Method and apparatus for ultrasound synthetic imagining
First Claim
1. An apparatus for ultrasound imaging, comprising:
- means for transmitting a plurality of ultrasonic tilted plane waves into a region, said ultrasonic tilted plane waves having different mean angles of inclination of their directions of propagation, for each of a plurality of imaged locations in the region;
means for acquiring respective sets of non-coherent raw data, without receive beamforming, in response to said ultrasonic tilted plane waves, each set of non-coherent raw data representing the time signals respectively received by an array of transducers in response to the corresponding ultrasonic tilted plane wave;
means for synthesizing at least one set of coherent raw data from the plurality of sets of non-coherent raw data for each of a plurality of virtual transmit focal zones in an imaged region, the at least one set of coherent raw data corresponding to backscattered echoes resulting from said virtual transmit focal zone and being synthesized by coherent addition of said respective sets of non-coherent raw data corresponding to the different mean angles of inclination of the directions of propagation of the ultrasonic tilted plane waves;
beamforming means for computing a beamformed signal by receive beamforming along at least one direction using the set of coherent raw data for each of a plurality of locations included in each of the virtual transmit focal zones, thus obtaining an image of the imaged region,wherein said virtual transmit focal zones are M straight lines in the imaged region, perpendicular to the array of transducers, andwherein said means for synthesizing at least one set of coherent raw data include at least means for computing a coherent raw data set RFcoherent for each of said straight lines by applying delays, corresponding to travel times of ultrasonic waves, to the non-coherent raw data for performing a virtual dynamic transmit focusing on said virtual transmit focal zone, assuming that the speed of sound c is homogeneous in the region, by the following formula;
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Abstract
A method for ultrasound imaging is provided. The method includes at least a transmission step, a coherence enhancing step, and a beamforming step. In the transmission step, a plurality of ultrasonic waves are transmitted into an imaged region and a set of raw data is acquired by an array of transducers in response to each ultrasonic wave. The ultrasonic waves have different spatial frequency content. In the coherence enhancing step, for each of a plurality of virtual transmit focal zones in the imaged region, at least one set of coherent data is synthesized from the sets of raw data. In the beamforming step, for each of a plurality of locations included in each of the virtual transmit focal zones, an image pixel is computed by beamforming, using the set of coherent data.
27 Citations
24 Claims
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1. An apparatus for ultrasound imaging, comprising:
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means for transmitting a plurality of ultrasonic tilted plane waves into a region, said ultrasonic tilted plane waves having different mean angles of inclination of their directions of propagation, for each of a plurality of imaged locations in the region; means for acquiring respective sets of non-coherent raw data, without receive beamforming, in response to said ultrasonic tilted plane waves, each set of non-coherent raw data representing the time signals respectively received by an array of transducers in response to the corresponding ultrasonic tilted plane wave; means for synthesizing at least one set of coherent raw data from the plurality of sets of non-coherent raw data for each of a plurality of virtual transmit focal zones in an imaged region, the at least one set of coherent raw data corresponding to backscattered echoes resulting from said virtual transmit focal zone and being synthesized by coherent addition of said respective sets of non-coherent raw data corresponding to the different mean angles of inclination of the directions of propagation of the ultrasonic tilted plane waves; beamforming means for computing a beamformed signal by receive beamforming along at least one direction using the set of coherent raw data for each of a plurality of locations included in each of the virtual transmit focal zones, thus obtaining an image of the imaged region, wherein said virtual transmit focal zones are M straight lines in the imaged region, perpendicular to the array of transducers, and wherein said means for synthesizing at least one set of coherent raw data include at least means for computing a coherent raw data set RFcoherent for each of said straight lines by applying delays, corresponding to travel times of ultrasonic waves, to the non-coherent raw data for performing a virtual dynamic transmit focusing on said virtual transmit focal zone, assuming that the speed of sound c is homogeneous in the region, by the following formula;
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2. An apparatus for ultrasound imaging, comprising:
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means for transmitting a plurality of ultrasonic tilted divergent waves into a region, said ultrasonic tilted divergent waves having different mean angles of inclination of their directions of propagation, for each of a plurality of imaged locations in the region; means for acquiring respective sets of non-coherent raw data, without receive beamforming, in response to said ultrasonic tilted divergent waves, each set of non-coherent raw data representing the time signals respectively received by an array of transducers in response to the corresponding ultrasonic tilted plane wave; means for synthesizing at least one set of coherent raw data from the plurality of sets of non-coherent raw data for each of a plurality of virtual transmit focal zones in an imaged region, the at least one set of coherent raw data corresponding to backscattered echoes resulting from said virtual transmit focal zone and being synthesized by coherent addition of said respective sets of non-coherent raw data corresponding to the different mean angles of inclination of the directions of propagation of the ultrasonic tilted divergent waves, for each of a plurality of virtual transmit focal zones in the region; beamforming means for computing a beamformed signal by receive beamforming along at least one direction using the set of coherent data for each of a plurality of locations included in each of the virtual transmit focal zones, thus obtaining an image of the imaged region, wherein said virtual transmit focal zones are M straight lines in the imaged region, perpendicular to the array of transducers, and wherein said means for synthesizing at least one set of coherent raw data include at least means for computing a coherent raw data set RFcoherent for each of said straight lines by applying delays, corresponding to travel times of ultrasonic waves, to the non-coherent raw data for performing a virtual dynamic transmit focusing on said virtual transmit focal zone, assuming that the speed of sound c is homogeneous in the region, by the following formula;
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3. A method for ultrasound imaging comprising at least the following successive steps:
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a) a transmission step in which a plurality of ultrasonic tilted plane waves are transmitted into an imaged region and respective sets of non-coherent raw data are acquired, without receive beamforming, by an array of transducers in response to said ultrasonic tilted plane waves, said ultrasonic tilted plane waves having different mean angles of inclination of their directions of propagation, for each of a plurality of imaged locations in the imaged region, each set of non-coherent raw data representing the time signals respectively received by an array of transducers in response to the corresponding ultrasonic tilted plane wave; b) a coherence enhancing step in which, for each of a plurality of virtual transmit focal zones in the imaged region, at least one set of coherent raw data, corresponding to backscattered echoes resulting from said virtual transmit focal zone, is synthesized from the plurality of sets of non-coherent raw data, the at least one set of coherent raw data being synthesized by coherent addition of said respective sets of raw data corresponding to the different mean angles of inclination of the directions of propagation of the ultrasonic tilted plane waves; c) a beamforming step in which, for each of a plurality of locations included in each of the virtual transmit focal zones, an image pixel is computed by receive beamforming, using the set of coherent raw data, thus obtaining an image of the imaged region, wherein in the coherence enhancing step b), the virtual transmit focal zones are M straight lines in the imaged region, perpendicular to the array of transducers, wherein the coherence enhancing step c) includes at least a first substep of computing a coherent data set RFcoherent for each of said straight lines by applying delays, corresponding to travel times of ultrasonic waves, to the non-coherent raw data for performing a virtual dynamic transmit focusing on said virtual transmit focal zone, assuming that the speed of sound c is homogeneous in the region, by the following formula; - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method for ultrasound imaging comprising at least the following successive steps:
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a) a transmission step in which a plurality of ultrasonic tilted divergent waves are transmitted into an imaged region and respective sets of non-coherent raw data are acquired, without receive beamforming, by an array of transducers in response to said ultrasonic tilted divergent waves, said ultrasonic tilted divergent waves having different mean angles of inclination of their directions of propagation, for each of a plurality of imaged locations in the region, each set of non-coherent raw data representing the time signals respectively received by an array of transducers in response to the corresponding ultrasonic wave; b) a coherence enhancing step in which, for each of a plurality of virtual transmit focal zones in the imaged region, at least one set of coherent raw data, corresponding to backscattered echoes resulting from said virtual transmit focal zone, is synthesized from the plurality of sets of non-coherent raw data, the at least one set of coherent raw data being synthesized by coherent addition of said respective sets of non-coherent raw data corresponding to the different mean angles of inclination of the directions of propagation of the ultrasonic tilted divergent waves; c) a beamforming step in which, for each of a plurality of locations included in each of the virtual transmit focal zones, an image pixel is computed by receive beamforming, using the set of coherent raw data, thus obtaining an image of the imaged region, wherein in the coherence enhancing step b), the virtual transmit focal zones are M straight lines in the imaged region, perpendicular to the array of transducers, wherein the coherence enhancing step c) includes at least a first substep of computing a coherent data set RFcoherent for each of said straight lines by applying delays, corresponding to travel times of ultrasonic waves, to the non-coherent raw data for performing a virtual dynamic transmit focusing on said virtual transmit focal zone, assuming that the speed of sound c is homogeneous in the region, by the following formula; - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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Specification