Mapping of flow parameters

• US 5,419,332 A
• Filed: 01/21/1994
• Issued: 05/30/1995
• Est. Priority Date: 08/02/1993
• Status: Expired due to Term

• Current Assignee: Elscint Limited (Elbit Imaging Limited)
• Original Assignee: Elscint Limited (Elbit Imaging Limited)
• Inventors: Sabbah, Benjamin, Bruck, Avraham, Friedman, Zvi
• Primary Examiner(s): MANUEL, GEORGE C
• Application Number:
  US08/183,869
• Time in Patent Office: 494 Days
• Field of Search: 128/661.07, 128/661.08, 128/661.09, 128/661.10, 128/660.05
• US Class Current: 600/455
• 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

Abstract

Automatic mapping of flow parameters in a ultrasound diagnostic imaging system including the steps of: selecting a region of interest (ROI), transmitting ultrasound signals along at least one line traversing blood vessels in the ROI, applying a train of pulses along each of said at least one line during a heart cycle, generating a spectral density function as a function time, displaying selected blood flow characteristics determined from said spectral density function.

Claims

1. An ultrasound diagnostic imaging method that provides blood flow parameters for analyzing blood flow, said method comprising the steps of:

selecting a region of interest in a sector scan image;

transmitting ultrasound signals along at least one line traversing said selected region of interest;

locating a plurality of gates to define gated sections along each of said at lest one line where blood vessels are traversed;

said transmitted ultrasound signals comprising a train of pulses transmitted along each of said at least one line for transmission through said gates;

receiving reflected spectral signals back from said gates,

converting said reflected spectral signals to a spectral density function of a variable that is proportional to velocity as a function of the time that extends over at least one heart cycle for each of said gates;

selecting at least one blood flow indice other than velocity to be determined; and

determining the flow indices from said spectral density function.

2. The ultrasound dianostic imaging method of claim 1 wherein said spectral density function is a maximum velocity shift envelope.

3. The ultrasound imaging method of claim 1 wherein said spectral density function is a maximum frequency shift envelope.

4. The ultrasound diagnostic imaging method of claim 1 wherein the step of transmitting the train of pulses along each of said lines comprises transmitting said train of pulses along of each of said lines individually for transmission through said gates during said at least one heart cycle.

5. The ultrasound diagnostic imaging method of claim 1 wherein the application of the train Doppler pulses along each of said lines individually are transmitted through all of said gates in each of said lines during said at least one heart cycle.

6. The ultrasound diagnostic imaging method of claim 1 wherein the step of applying a train of pulses along each of said lines comprises gating the train of pulses responsive to said at least one heart cycle.

7. The ultrasound diagnostic imaging method of claim 1 including the step of displaying the selected blood flow parameter values in a plurality of colors wherein a first color is used below a certain value of the at least one selected blood flow parameter and a second color is used above that certain value.

8. The ultrasound diagnostic imaging method of claim 1 including the step of displaying the selected blood flow parameter values in a plurality of colors wherein there is a one-to-one correspondence between said values and said colors.

9. The ultrasound diagnostic imaging method of claim 1 including the step of displaying the selected blood flow parameter values in a plurality of shades wherein a first shade is used below a certain value of the selected blood flow parameter and a second shade is used above said certain value of the selected blood flow parameter.

10. The ultrasound diagnostic imaging method of claim 1 including the step of displaying the selected blood flow parameter values in a plurality of shades wherein there is a one-to-one correspondence between said values and said shades.

11. The ultrasound diagnostic imaging method of claim 1 wherein scanning of the region of interest is performed over a plurality of lines on a sequential line after line basis.

12. The ultrasound diagnostic imaging method of claim 11 including the step of transmitting at least one ultrasound pulse out of the complete number of pulses to be transmitted over each line prior to transmitting over a next line in the sequential line after line basis.

13. The ultrasound diagnostic imaging method of claim 11 including the step of transmitting the complete number of pulses to be transmitted over each line prior to transmitting over the next line.

14. The ultrasound diagnostic imaging method of claim 1 including a step of preventing misalignment between the sector scan image and the flow parameter image.

15. The ultrasound diagnostic imaging method of claim 14 wherein the step of preventing misalignment between the sector scan image and the flow parameter image comprises simultaneously generating both the sector scan image and the flow parameter image throughout the region of interest to provide a flow parameter image superimposed on the two-dimensional sector scan image.

16. An ultrasound diagnostic imaging method that prevents misalignment between a sector scan image in the flow parameter image, such system comprising the steps of:

selecting a region of interest in an original sector scan image;

transmitting ultrasound signals along at least one line traversing said selected region of interest;

locating a plurality of gates to define gated sections along each of said at least one line where blood vessels are traversed;

said ultrasound signals comprising a train of pulses along each of said at least one line to be transmitted through said gates;

receiving spectral signals back through said gate;

converting said spectral signals to a spectral density function of a variable that is proportional to the velocity as a function of time for each of said gates;

selecting at least one blood flow parameter to be determined;

determining the selected blood flow parameter form said spectral density function; and

locking cross-hairs on to the region of interest of the original sector scan image to correlate the original sector scan image through a series of sector scan images that is taken during the pulse scanning and reduce artifacts caused by relative motion between tissues in the sector scan image and the transducer used for transmitting the ultrasound signals along said at least one line.

17. The ultrasound diagnostic imaging system of claim 16 wherein said spectral density function is a maximum velocity shift envelope.

18. The ultrasound diagnostic imaging system of claim 16 wherein said spectral density function is a maximum frequency shift envelope.

19. An ultrasound diagnostic imaging method that provides blood flow parameters for analyzing blood flow, said method comprising the steps of:

selecting a region of interest in a sector scan image;

transmitting ultrasound signals along at least one line traversing said selected region of interest;

locating a plurality of gates to define gated sections along each of said at least one line where blood vessels are traversed;

said transmitted ultrasound signals comprising a train of pulses transmitted along each of said at least one line for transmission through said gates;

receiving reflected spectral signals through said gates;

converting said reflected spectral signals to a spectral density function of a variable that is proportional to the velocity as a function of time that extends over at least one half cycle for each of said gates;

selecting at least one blood vessel indice to be determined;

determining the selected blood flow indices from said spectral density function, and

scanning the region of interest on an interlaced line basis.

20. An ultrasound diagnostic imaging method of claim 19 including the step of transmitting at least one ultrasound pulse of the complete number of pulses to be transmitted over each line prior to transmitting over a next line in the interlaced line after line basis.

21. An ultrasound diagnostic imaging method that provides blood flow parameters for analyzing blood flow, said method comprising steps of:

selecting a region of interest in a sector scan image;

transmitting ultrasound signals along at least one line traversing said selected region of interest;

locating a plurality of gates to define gated sections along each of said at least one line where blood vessels are traversed;

said transmitted ultrasound signals comprising a train of pulses transmitted along each of said ate least one line for transmission through said gates;

receiving reflected spectral signals back through said gates;

converting said reflected spectral signals to a spectral density function of a variable that is proportional to velocity as a function of time that extends over at least one heart cycle for each of said gates;

selecting at least one flow parameter to be determined;

determining the selected flow parameter from said spectral density function; and

locking a TV tracker onto the image to correlate the original image through a series of two-dimensional images taken during the scanning, to reduce artifacts caused by the relative motion of the tissue and the transducer.