Synthetically focused ultrasonic diagnostic imaging system for tissue and flow imaging

• US 6,860,854 B2
• Filed: 10/03/2003
• Issued: 03/01/2005
• Est. Priority Date: 04/30/2002
• Status: Expired due to Term

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Robinson, Brent S.
• Primary Examiner(s): Jaworski, Francis J.
• Application Number:
  US10/679,093
• Publication Number:
  US 20040068188A1
• Time in Patent Office: 515 Days
• Field of Search: 600/437, 600440-441, 600/443, 600/447, 600454-456, 600/458, 736/02, 736/25, 736/26, 128/916
• US Class Current: 600/447
• CPC Class Codes: G01S 15/8918 the array being linear
• CPC Class Codes: G01S 15/8925 the array being a two-dimensional transducer configuration, i.e. matrix or orthogonal linear arrays
• CPC Class Codes: G01S 15/8927 using simultaneously or sequentially two or more subarrays or subapertures
• CPC Class Codes: G01S 15/8977 using special techniques for image reconstruction, e.g. FFT, geometrical transformations, spatial deconvolution, time deconvolution
• CPC Class Codes: G01S 15/8979 Combined Doppler and pulse-echo imaging systems
• CPC Class Codes: G01S 7/52028 using digital techniques

Abstract

A synthetic focus ultrasound system is described which is operated in a hybrid fashion. System operation alternates between synthetic focus acquisition and conventional focused beam acquisition. This makes possible, for example, the acquisition and display of harmonic images. Speckle artifacts in the synthetic focused ultrasound images may be reduced by combining signals from different sub-apertures which view the image field from different look directions. In a described embodiment, sets of motion maps are be produced for different sub-apertures of the array transducer, then compounded to reduce speckle. One or more identified regions of interest within a synthetic focused ultrasound image may be processed differently from other regions of the image to highlight or better define particular motional characteristics within the regions of interest, such as turbulent flow or different velocities of flow or motion.

Claims

1. A synthetic focus ultrasound system comprising:

an array of transducer elements;

a transmitter coupled to the transducer which acts to produce, in a first mode, transmit events by the transmission from an individual element or group of elements over the full image field, and in a second mode, to produce focused transmit beams from a plurality of transducer elements;

a receiver coupled to the transducer which receives echo signals from elements of the array in response to a transmit event or a focused transmit beam;

a processor coupled to the receiver which selectively performs synthetic focusing of signals received in response to transmit events or focused receive beams in response to focused transmit beams; and

a display which displays images produced from synthetically focused and focused beam transmit signals.

2. The synthetic focus ultrasound system of claim 1, wherein the echo signals received from elements of the array in response to a transmit event comprise linear signals, and wherein the echo signals received in response to a focused transmit beam comprise nonlinear signals.

3. The synthetic focus ultrasound system of claim 2, wherein the linear signals comprise fundamental frequency signals, and wherein the nonlinear signals comprise harmonic frequency signals.

4. The synthetic focus ultrasound system of claim 1, wherein the processor produces motion depicting signals through synthetic focusing, and tissue depicting signals through the focusing of echo signals received in response to a focused transmit beam.

5. The synthetic focus ultrasound system of claim 4, wherein the motion depicting signals and the tissue depicting signals are used in a displayed color flow image.

6. The synthetic focus ultrasound system of claim 5, wherein the echo signals received in response to a transmit event are at a fundamental frequency and wherein the echo signals received in response to a focused transmit beam are at a harmonic frequency.