Ultrasound Imaging

• US 20150126870A1
• Filed: 06/28/2012
• Published: 05/07/2015
• Est. Priority Date: 06/28/2012
• Status: Active Grant

• Current Assignee: B-K Medicals Aps
• Original Assignee: B-K Medicals Aps
• Inventors: Jensen, Henrik, Seerup, Gert, Bagge, Jan Peter
• Granted Patent: US 9,883,849 B2
• Time in Patent Office: Days
• US Class Current: 600/447
• CPC Class Codes: A61B 8/085 for locating body or organic structures, e.g. tumours, calculi, blood vessels, nodules
• CPC Class Codes: A61B 8/4488 the transducer being a phased array
• CPC Class Codes: A61B 8/4494 characterised by the arrangement of the transducer elements devices for short-range imaging using particular transducer elements arrangements under G01S15/8909; arrangements of transducers in generation of mechanical vibrations of infrasonic, sonic or ultrasonic frequency B06B1/0607
• CPC Class Codes: A61B 8/486 involving arbitrary m-mode
• CPC Class Codes: A61B 8/5207 involving processing of raw data to produce diagnostic data, e.g. for generating an image reconstruction G06T11/00
• CPC Class Codes: G01S 15/89 for mapping or imaging
• CPC Class Codes: G01S 15/8927 using simultaneously or sequentially two or more subarrays or subapertures
• CPC Class Codes: G01S 15/8963 using pulse inversion
• CPC Class Codes: G01S 15/8997 using synthetic aperture techniques
• CPC Class Codes: G01S 7/52038 involving non-linear properties of the propagation medium or of the reflective target
• CPC Class Codes: G01S 7/521 Constructional features

Abstract

A method includes concurrently exciting neighboring pairs of transducer elements of an array for at least two transmits, wherein the array has a focus in a range of ten to twenty centimeters with a f-number of five or less. The method further includes receiving first echoes with individual transducer elements of a first sub-set of the transducer elements for a first of the at least two transmits, and receiving second echoes with individual transducer elements of a second sub-set of the transducer elements for a second of the at least two transmits. The method further includes extracting second harmonics from the echoes of the at least two transmits. The method further includes beamforming the extracted second harmonics. The method further includes generating an image based on the beamformed extracted second harmonics.

Claims

1. An ultrasound imaging system, comprising:

a transducer, including;

an array of a plurality of transducer elements that emit ultrasonic signals that traverse an object in an imaging field of view and receive echoes generated in response to an interaction between the ultrasonic signals and the object, wherein the transducer has a focus in a range of ten to twenty centimeters with a f-number of five or less;

transmit circuitry that generates a first set of first excitation pulses that excites the plurality of transducer elements to emit first ultrasonic signals and, after a predetermined time delay, a second set of second excitation pulses that excites the plurality of transducer elements to emit second ultrasonic signals, wherein the transmit circuitry sequentially excites groups of two or more transducer elements with the first set of first excitation pulses and with the second set of second excitation pulses, exciting all of the transducer elements in each excitation;

receive circuitry that receives first echoes generated in response to the first set of first excitation pulses and received by a first sub-set of the transducer elements and extracts a first set of harmonic components from the first echoes, and that receives second echoes generated in response to the second set of second excitation pulses and received by a second different sub-set of the transducer elements and extracts a second set of harmonic components from the second echoes; and

a beamformer that beamforms the extracted first set of harmonic components producing first intermediate data and beamforms the extracted second set of harmonic components producing second intermediate data.

2. The system of claim 1, wherein the first set of first excitation pulses includes first pulses followed by first inverted copies of the first pulses and the first echoes include echoes corresponding to the first pulses and first echoes corresponding to the first inverted copies of the first pulses, and further comprising:

an adder that adds the first echoes corresponding to the first pulses and the first echoes corresponding to the first inverted copies of the first pulses, cancelling fundamental components and odd harmonics of the first echoes and extracting second harmonic components of the first echoes, generating the first set of harmonic components.

3. The system of claim 2, wherein the second set of second excitation pulses includes second pulses followed by second inverted copies of the second pulses and the second echoes include second echoes corresponding to the second pulses and second echoes corresponding to the second inverted copies of the second pulses, and the adder adds the second echoes corresponding to the second pulses and the second echoes corresponding to the second inverted copies of the second pulses, cancelling fundamental components and odd harmonics of the second echoes and extracting second harmonic components of the second echoes, generating the second set of harmonic components.

4. The system of claim 1, further comprising:

a bandpass filter that filters the first echoes and the second echoes, passing second harmonic components of the first and second echoes, generating the first and the second set of harmonic components.

5. The system of claim 1, wherein the beamformer beamforms the first set of harmonic components generating the first intermediate data and that beamforms the second set of harmonic components generating the second intermediate data.

6. The system of claim 1, further comprising:

a scan converter that scan converts a plurality of scan lines, generating an image of the object.

7. The system of claim 1, wherein the first sub-set of the transducer elements corresponds to even or odd numbered transducer elements and the second sub-set of the transducer elements corresponds to the other of the even or odd numbered transducer elements.

8. The system of claim 1, wherein the ultrasonic signals have a center frequency on an order of three megahertz.

9. The system of claim 1, wherein the focus is on an order of twelve centimeters.

10. The system of claim 1, wherein the focus is on an order of fifteen centimeters.

11. The system of claim 1, wherein the transducer array has an approximately square footprint.

12. The system of claim 1, wherein the transducer array has an active length on an order of thirty-two millimeters and an active width on an order of thirty-two millimeters.

13. A method, comprising:

transmitting a first set of first excitation pulses that excites a plurality of transducer elements of an array to emit first ultrasonic signals and, after a predetermined time delay, a second set of second excitation pulses that excites the plurality of transducer elements to emit second ultrasonic signals, wherein groups of two or more transducer elements are sequentially excited with the first set of first excitation pulses and with the second set of second excitation pulses;

receiving first echoes generated in response to the first set of first excitation pulses and received by a first sub-set of the transducer elements and extracting a first set of harmonic components from the first echoes, and receiving second echoes generated in response to the second set of second excitation pulses and received by a second different sub-set of the transducer elements and extracting a second set of harmonic components from the second echoes; and

beamforming the extracted first set of harmonic components producing first intermediate data and beamforming the extracted second set of harmonic components producing second intermediate data,

wherein the transducer has a focus in a range of ten to twenty centimeters and a f-number of five or less.

14. The method of claim 13, wherein transmitting the first set of first excitation pulses comprises transmitting first pulses followed by first inverted copies of the first pulses, and receiving the first echoes includes receiving echoes corresponding to the first pulses and first echoes corresponding to the first inverted copies of the first pulses;

and further comprising;

adding the first echoes corresponding to the first pulses and the first echoes corresponding to the first inverted copies of the first pulses, thereby cancelling fundamental components and odd harmonics of the first echoes and extracting second harmonic components of the first echoes, generating the first set of harmonic components.

15. The method of claim 14, wherein transmitting the second set of second excitation pulses comprises transmitting second pulses followed by second inverted copies of the second pulses, and receiving the second echoes includes receiving echoes corresponding to the second pulses and second echoes corresponding to the second inverted copies of the second pulses;

and further comprising;

adding the second echoes corresponding to the second pulses and the second echoes corresponding to the second inverted copies of the second pulses, thereby cancelling fundamental components and odd harmonics of the second echoes and extracting second harmonic components of the second echoes, generating the second set of harmonic components.

16. The method of claim 13, further comprising:

bandpass filtering the first echoes and the second echoes, passing second harmonic components of the first and second echoes and generating the first and the second set of harmonic components.

17. The method of claim 13, further comprising:

beamforming the first set of harmonic components to generate the first intermediate data and beamforming the second set of harmonic components to generate the second intermediate data.

18. The method of claim 13, the beamforming, comprising:

adding the first intermediate data and the second intermediate data, producing the scan line.

19. The method of claim 13, wherein the first sub-set of the transducer elements corresponds to even or odd numbered transducer elements and the second sub-set of the transducer elements corresponds to the other of the odd or even numbered transducer elements.

20. The method of claim 13, wherein the first set of first excitation pulses and the second set of second excitation pulses generate ultrasonic signals with a center frequency on an order of three megahertz.

21. The method of claim 13, wherein the focus is on an order of twelve centimeters.

22. The method of claim 13, wherein the focus is on an order of fifteen centimeters.

23. The method of claim 13, wherein the transducer array has an active length and an active width that are approximately equal.

24. A method, comprising:

concurrently exciting neighboring pairs of transducer elements of an array for at least two transmits, wherein the array has a focus in a range of ten to twenty centimeters with a f-number of five or less;

receiving first echoes with individual transducer elements of a first sub-set of the transducer elements for a first of the at least two transmits, and receiving second echoes with individual transducer elements of a second sub-set of the transducer elements for a second of the at least two transmits;

extracting second harmonics from the echoes of the at least two transmits;

beamforming the extracted second harmonics; and

generating an image based on the beamformed extracted second harmonics.