ULTRASOUND PULSE-WAVE DOPPLER MEASUREMENT OF BLOOD FLOW VELOCITY AND/OR TURBULENCE

• US 20110196237A1
• Filed: 02/04/2011
• Published: 08/11/2011
• Est. Priority Date: 02/05/2010
• Status: Active Grant

• Current Assignee: BK Medical Holding Company, Inc. (GE Healthcare Technologies, Inc.)
• Original Assignee: Ultrasonix Medical Corporation (GE Healthcare Technologies, Inc.)
• Inventors: DICKIE, Kris, PELISSIER, Laurent, ZHUANG, Bo
• Granted Patent: US 9,204,858 B2
• Time in Patent Office: Days
• US Class Current: 600/454
• 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 8/08 Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• CPC Class Codes: A61B 8/0891 for diagnosis of blood vessels
• CPC Class Codes: A61B 8/461 Displaying means of special interest
• CPC Class Codes: A61B 8/463 characterised by displaying multiple images or images and diagnostic data on one display composite display in devices for short-range imaging with acoustic waves G01S7/52074
• CPC Class Codes: A61B 8/466 adapted to display 3D data 3D imaging and stereoscopic displays in devices for short-range imaging with acoustic waves G01S15/8993 and G01S7/52068, respectively; 3D image rendering G06T15/00; manipulating 3D models for computer graphics G06T19/00
• CPC Class Codes: A61B 8/467 characterised by special input means
• CPC Class Codes: A61B 8/488 involving Doppler signals
• CPC Class Codes: A61B 8/543 involving acquisition triggered by a physiological signal
• CPC Class Codes: G01S 15/8984 Measuring the velocity vector
• CPC Class Codes: G01S 7/52073 Production of cursor lines, markers or indicia by electronic means

Abstract

Apparatus and methods for measuring and analyzing blood flow in vessels in the bodies of living subjects are provided. The true velocity vector, or a projection thereof onto a scan plane, for blood flowing at a location in a vessel is determined from multiple Doppler velocity components. The true velocity vector is displayed as a directional marker on an image comprising the vessel. The true velocity magnitude and angle, and scalar blood flow characteristics derived therefrom, are plotted as a functions of time and/or position across the depiction of the blood vessel in the image. Time intervals for which blood flow characteristic data is displayed and/or determined may be user configurable.

Claims

1. A method for displaying blood flow information concerning blood in a vessel, the method comprising:

producing an ultrasound image of the vessel;

obtaining a true velocity vector of blood passing through a sample volume located in the vessel; and

displaying a vector-marker corresponding to the true velocity vector on the ultrasound image at a location corresponding to the sample volume.

2. A method according to claim 1 comprising:

for each of a plurality of time intervals;

obtaining a true velocity vector of blood passing through the sample volume; and

displaying a vector-marker corresponding to the true velocity vector on the ultrasound image at a location corresponding to the sample volume.

3. A method according to claim 2 wherein only one vector-marker corresponding to the true velocity vector is displayed on the ultrasound image at the location corresponding to the sample volume at a time.

4. A method according to claim 2 wherein a plurality of vector-markers corresponding to true velocity vectors of different time intervals are concurrently displayed on the ultrasound image at the location corresponding to the sample volume.

5. A method according to claim 4 wherein concurrently displayed vector-markers differ in appearance according to the temporal order of their corresponding time intervals.

6. A method according to claim 5 wherein the concurrently displayed vector-markers comprise arrows, and differ in their appearance by at least the sizes of heads on the arrows.

7. A method according to claim 5 wherein among concurrently displayed vector-markers, a vector marker corresponding to true velocity vector of an earliest time interval appears more faintly that another concurrently displayed vector-marker.

8. A method according to claim 4 wherein the different time intervals are not contiguous in time.

9. A method according to claim 4 wherein a time separation between the different time intervals is specified by a user.

10. A method according to claim 1 comprising:

displaying a scale that associates vector-marker length with a range of numeric velocity magnitude values.

11. A method according to claim 1 comprising:

for each of a plurality of time intervals;

obtaining a true velocity vector of blood passing through the sample volume located in the vessel;

determining a scalar blood flow characteristic value based on the true velocity vector; and

plotting the scalar blood flow characteristic value on a timescale at a location corresponding to the time interval.

12. A method according to claim 11 wherein the scalar blood flow characteristic comprises velocity angle.

13. A method according to claim 11 wherein the scalar blood flow characteristic comprises velocity magnitude.

14. A method according to claim 13 wherein a plurality of velocity magnitude values corresponding to different time intervals are plotted together at a single location along the timescale.

15. A method according to claim 14 wherein the plurality of velocity magnitude values corresponding to different time intervals are plotted together at the location along the timescale as a single point whose location along a value axis is determined by a computable function of the plurality of velocity magnitude values.

16. A method according to claim 14 wherein the plurality of velocity magnitude values corresponding to different time intervals are plotted together as a plurality of different points at different locations along a value axis.

17. A method according to claim 14 wherein the plurality of velocity magnitude values comprises a first plurality of velocity magnitude values in a first range and a second plurality of velocity magnitude values in a second range different from the first range, and wherein the first plurality of velocity magnitude values are plotted as a first point defined by the location along the timescale and a first coordinate along the value axis, and the second plurality of velocity magnitude values are plotted as a second point defined by the location along the timescale and a second coordinate along the value axis.

18. A method according to claim 17 wherein the first point has a display attribute corresponding to the number of velocity magnitude values in the first plurality of velocity magnitude values.

19. A method according to claim 18 wherein the display attribute comprises at least one of color and brightness.

20. A method for displaying blood flow information concerning blood in a vessel, the method comprising:

for each of a plurality of sample volumes in the vessel;

obtaining a velocity vector for blood passing through the sample volume;

determining a scalar blood flow characteristic based on the velocity vector; and

plotting the scalar blood flow characteristic on a first graph at a location corresponding to the sample volume.

21. A method according to claim 20 wherein the scalar blood flow characteristic comprises a magnitude of the velocity vector.

22. A method according to claim 20 wherein the scalar blood flow characteristic comprises an angle of the velocity vector.

23. A method according to claim 20 comprising,

for each of the plurality of sample volumes:

obtaining a measurement of a strength of ultrasound echos returned from the sample volume; and

determining an instantaneous volumetric rate of blood flow through the sample volume based on the echo strength measurement and velocity magnitude value,

wherein the scalar blood flow characteristic comprises the instantaneous volumetric rate of blood flow.

24. A method according to claim 23 comprising:

for each of the plurality of sample volumes;

for each of a plurality of time intervals;

obtaining a measurement of a strength of ultrasound echos returned from the sample volume; and

determining an instantaneous volumetric rate of blood flow through the sample volume for the time interval based on the echo strength measurement and velocity magnitude value; and

determining a cumulative blood flow volume through the sample volume based on the instantaneous volumetric rates of blood flow determined for the plurality of time intervals,

wherein the scalar blood flow characteristic comprises cumulative blood flow volume over the plurality of time intervals.

25. A method according to claim 20 wherein the plurality of sample volumes lie along a chord of a cross-section of the vessel.

26. A method according to claim 20 comprising:

producing an ultrasound image of the vessel; and

determining the location of the plurality of sample volumes in the vessel by a correspondence between an elongate user controllable cursor positioned on the image and pixels of the image.

27. A method according to claim 26 wherein the step of plotting the scalar blood flow characteristic on the first graph at the location corresponding to the sample volume comprises plotting the scalar blood flow characteristic at a location on the ultrasound image of the vessel corresponding to the sample volume.

28. A vector Doppler ultrasound system for displaying blood velocity information for blood inside a body, the system comprising:

a controller;

an ultrasound transducer connected to the controller to provide ultrasound echo signals;

a display connected to the controller, the display having a user-positionable cursor; and

an input device connected to the controller;

wherein the controller is configured to;

generate an image of the body based on ultrasound echo signals from the ultrasound transducer;

position the user-positionable cursor on the display according to input from the input device;

determine a location of a sample volume in the body according to a correspondence between the position of the user-positionable cursor and the image of the body;

obtain a true velocity vector of blood passing through the sample volume located in the vessel; and

display a vector-marker corresponding to the true velocity vector on the image at a location corresponding to the sample volume.

29. A vector Doppler ultrasound system for displaying blood velocity information for blood inside a body, the system comprising:

a controller;

an ultrasound transducer connected to the controller to provide ultrasound echo signals;

a display connected to the controller, the display having a user-positionable cursor; and

an input device connected to the controller;

wherein the controller is configured to;

generate an image of the body based on ultrasound echo signals from the ultrasound transducer;

position the user-positionable cursor on the display according to input from the input device;

determine a location of a sample volume in the body according to a correspondence between the position of the user-positionable cursor and the image of the body;

generate a true velocity vector of blood passing through the sample volume located in the vessel based on ultrasound echo signals from the ultrasound transducer;

determine a scalar blood flow characteristic based on the true velocity vector; and

display the scalar blood flow characteristic on the display.