Chord propagation velocity measurement system and method for an ultrasound imaging system

• US 6,196,971 B1
• Filed: 04/02/1999
• Issued: 03/06/2001
• Est. Priority Date: 04/02/1999
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Friedman, Joel, Prater, David M
• Primary Examiner(s): Lateef, Marvin M.
• Assistant Examiner(s): Imam, Ali M.
• Application Number:
  US09/285,842
• Time in Patent Office: 704 Days
• Field of Search: 600/438, 600/437, 600/443, 600/447, 600/441, 600/442, 600/485, 600/483, 600/504-507, 736/29, 73/1.DV
• US Class Current: 600/450
• CPC Class Codes: A61B 5/0285 Measuring or recording phase velocity of blood waves
• CPC Class Codes: A61B 8/06 Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00
• CPC Class Codes: A61B 8/13 Tomography A61B8/10, A61B8/12 take precedence; tomography for radiation diagnosis A61B6/02
• CPC Class Codes: A61B 8/488 involving Doppler signals
• CPC Class Codes: G01S 15/8979 Combined Doppler and pulse-echo imaging systems
• CPC Class Codes: G01S 7/52036 using analysis of echo signal for target characterisation
• CPC Class Codes: G01S 7/52066 Time-position or time-motion displays

Abstract

A chord propagation velocity measurement (CPVM) system is used in connection with, for example, a brightness-mode (B-mode) or doppler ultrasound imaging system. The CPVM system monitors ultrasound data provided to it by the ultrasound imaging system and enhances the functionality of the ultrasound imaging system by providing a chord propagation velocity (CPV) associated with a body region, such as a blood vessel in a living thing. The CPV is indicative of the stiffness of the body region. In architecture, the CPVM system includes a tissue processor connected to the scanner of the ultrasound system designed to analyze each acoustic scan line and to determine a category (type of region, for example, blood or tissue) for each point along each acoustic scan line. A display produces an image generated from acoustic scan lines. A user input mechanism permits a user to identify a region of interest in the image. The tissue processor produces samples based upon the region of interest in the image. A CPV determination system, which is connected to the tissue processor, acquires a plurality of the samples from different subregions along a longitudinal span of the region for each of a plurality of different cycles, derives a plurality of composites, one for each subregion, by combining corresponding samples from different cycles, and produces a CPV based upon the plurality of composites. Preferably, the CPV is displayed, printed, or otherwise output by the CPVM system to the user of the ultrasound imaging system in real time to permit immediate analysis, and evaluation of the body region by the user.

Claims

1. A method for quantifying stiffness of a region of a body, comprising the steps of:

acquiring a plurality of measured samples from different subregions along a longitudinal span of the body region for each of a plurality of different electrocardiogram (ECG) cycles;

deriving a plurality of composites, one for each subregion, by combining corresponding samples from different ECG cycles; and

producing a chord propagation velocity based upon said plurality of composites, said chord propagation velocity being indicative of the stiffness.

2. The method of claim 1, further comprising the steps of:

determining a plurality of cross sectional areas from different subregions along said longitudinal span, each said cross sectional area based upon a chord length and width; and

deriving said composites by mathematically combining corresponding areas from different ECG cycles.

3. The method of claim 1, further comprising the steps of:

determining chord lengths from different subregions along said longitudinal span based upon said samples; and

deriving said composites by mathematically combining corresponding chord lengths from different ECG cycles.

4. The method of claim 1, further comprising the step of mathematically averaging said corresponding samples in order to derive said composites.

5. The method of claim 1, further comprising the steps of:

displaying said chord propagation velocity on a computer display; and

updating said chord propagation velocity on the computer display over time.

6. The method of claim 1, further comprising the steps of:

producing a plurality of said chord propagation velocities, each corresponding with a different subregion of the region; and

displaying a graph on a computer display showing said chord propagation velocities versus said subregions.

7. The method of claim 1, further comprising the steps of:

determining said chord propagation velocity by estimating the time shift between said composites, said chord propagation velocity being determined by utilizing estimated time shifts and distances between subregions.

8. The method of claim 1, further comprising the step of:

determining a time shift of a feature associated with said composites in order to produce said chord propagation velocity.

9. The method of claim 8, wherein said feature is a falling edge of a change in chord length caused by pumping activity produced by a heart in the body.

10. The method of claim 1, wherein said body is a living thing and said region is a blood vessel within the body.

11. The method of claim 1, further comprising the step of utilizing a brightness mode ultrasound imaging system to acquire said samples.

12. The method of claim 1, further comprising the step of utilizing a doppler ultrasound imaging system to acquire said samples.

13. The method of claim 1, wherein said samples and said ECG cycles are asynchronous and further comprising the step of:

re-sampling said measured samples to normalize them relative to said ECG cycles, prior to deriving said plurality of said composites.

14. The method of claim 1, further comprising the step of acquiring said chord samples by using a linear probe.

15. The method of claim 1, further comprising the step of acquiring said chord samples by using a sector probe.

16. The method of claim 1, further comprising the step of acquiring said chord samples by using a curved linear array probe.

17. A system for quantifying stiffness with a region of a body, comprising:

first means for acquiring a plurality of measured samples from different subregions along a longitudinal span of the body region for each of a plurality of different electrocardiogram (ECG) cycles;

second means for deriving a plurality of composites, one for each subregion, by combining corresponding samples from different ECG cycles; and

third means for producing a chord propagation velocity based upon said plurality of composites, said chord propagation velocity being indicative of the stiffness.

18. An ultrasound imaging system, comprising:

an ultrasound transducer designed to transmit and receive ultrasound signals;

an ultrasound scanner in electrical communication with said transducer, said scanner designed to produce acoustic scan lines based upon said ultrasound signals;

a user output mechanism in electrical communication with said scanner, said user output mechanism designed to produce an image generated by said acoustic scan lines;

a user input mechanism in electrical communication with said scanner, said user input mechanism designed to permit a user to identify a region of interest in said image;

a processor in electrical communication with said scanner, said processor designed to acquire a plurality of measured samples from different subregions along a longitudinal span of a body region within said region of interest for each of a plurality of different electrocardiogram (ECG) cycles, to derive a plurality of composites, one for each subregion, by combining corresponding samples from different ECG cycles, and to produce a chord propagation velocity based upon said plurality of composites, said chord propagation velocity being indicative of the stiffness.