Methods and systems for ultrasound imaging

Patent metadata

Field	Value
Publication number	US-12390197-B2
Application number	US-202118019618-A
Country	US
Kind code	B2
Filing date	Aug 5, 2021
Priority date	Aug 6, 2020
Publication date	Aug 19, 2025
Grant date	Aug 19, 2025

Abstract

There is provided a method for ultrasound imaging comprising applying an ultrasound modulation wave at a fixed frequency F 1 and a period P 1 to a target in a body, the body having received an injection of microbubbles through a fluid, the modulation wave causing the microbubbles to undergo stable acoustic cavitation, emitting, toward the target and concurrently with the modulation wave, ultrasound imaging pulses centered at a frequency F 2 and having a pulse repetition period of n*P 1 and a pulse delay of m*P 1 /k, where the pulse delay varies with m, m<k, and k>1, detecting reflections of the ultrasound pulses by the microbubbles after each emission for a duration corresponding to a maximum depth of the target, and forming ultrasound images from the reflections.

First claim

The invention claimed is:

1. A method for ultrasound imaging comprising:
applying a continuous ultrasound modulation wave at a fixed frequency F 1 and a period P 1 to a target in a body, the body having received an injection of microbubbles through a fluid, the modulation wave causing the microbubbles to undergo stable acoustic cavitation, the modulation wave being a treatment beam;
emitting, toward the target and concurrently with the modulation wave, ultrasound imaging pulses centered at a frequency F 2 and having a pulse repetition period of n*P 1 and a pulse delay of m*P 1 /k, where the pulse delay varies with m, m<k, and k>1, and where n and k are defined to synchronize the ultrasound imaging pulses with the continuous modulation wave by positioning each ultrasound imaging pulse within a given cycle of the continuous modulation wave;
detecting reflections of the ultrasound imaging pulses by the microbubbles after each emission for a duration corresponding to a maximum depth of the target; and
forming ultrasound images from the reflections to determine, based on the ultrasound images, a position of the treatment beam in real-time.

2. The method of claim 1 , wherein forming the ultrasound images comprises performing a Fourier analysis in slow time to compute a power spectrum of pixel intensity oscillation.

3. The method of claim 1 , wherein the modulation wave is a high intensity focused ultrasound (HIFU).

4. The method of claim 1 , wherein the body is an organ.

5. The method of claim 1 , wherein forming the ultrasound images comprises forming X sets of Y images, where each detection of a reflection produces one of the images Y, and the Y images are grouped into the X sets.

6. The method of claim 5 , further comprising generating a global image of the position of the treatment beam over time from the X sets of Y images.

7. The method of claim 1 , wherein k<10.

8. The method of claim 1 , wherein forming the ultrasound images comprises forming the ultrasound images in real-time and displaying the ultrasound images.

9. The method of claim 8 , further comprising displacing the treatment beam from a first position to a second position, and confirming the displacing from updated ultrasound images.

10. The method of claim 2 , wherein a magnitude of Fourier coefficients in each pixel of the ultrasound images characterizes an intensity of a local pressure field generated by the treatment beam.

11. An imaging system comprising:
a modulation wave generator coupled to an ultrasound transducer configured for emitting a continuous ultrasound modulation wave at a fixed frequency F 1 and a period P 1 to a target in a body, the body having received an injection of microbubbles through a fluid, the modulation wave causing the microbubbles to undergo stable acoustic cavitation, the modulation wave being a treatment beam; and
an imaging device coupled to at least one probe and configured for:
emitting, toward the target and concurrently with the modulation wave, ultrasound imaging pulses centered at a frequency F 2 and having a pulse repetition period of n*P 1 and a pulse delay of m*P 1 /k, where the pulse delay varies with m, m<k, and k>1, and where n and k are defined to synchronize the ultrasound imaging pulses with the continuous modulation wave by positioning each ultrasound imaging pulse within a given cycle of the continuous modulation wave;
detecting reflections of the ultrasound imaging pulses by the microbubbles after each emission for a duration corresponding to a maximum depth of the target; and
forming ultrasound images from the reflections to determine, based on the ultrasound images, a position of the treatment beam in real-time.

12. The imaging system of claim 11 , wherein forming the ultrasound images comprises performing a Fourier analysis in slow time to compute a power spectrum of pixel intensity oscillation.

13. The imaging system of claim 12 , wherein a magnitude of Fourier coefficients in each pixel of the ultrasound images characterizes an intensity of a local pressure field generated by the treatment beam.

14. The imaging system of claim 11 , wherein the modulation wave is a high intensity focused ultrasound (HIFU).

15. The imaging system of claim 11 , wherein the body is an organ.

16. The imaging system of claim 11 , wherein forming the ultrasound images comprises forming X sets of Y images, where each detection of a reflection produces one of the images Y, and the Y images are grouped into the X sets.

17. The imaging system of claim 16 , wherein the imaging device is further configured for generating a global image of the position of the treatment beam over time from the X sets of Y images.

18. The imaging system of claim 11 , wherein k<10.

19. The imaging system of claim 11 , wherein forming the ultrasound images comprises forming the ultrasound images in real-time and displaying the ultrasound images.

20. A method for applying a treatment beam to a subject, the method comprising:
applying the treatment beam as a continuous ultrasound modulation wave at a fixed frequency F 1 and a period P 1 to a target in the subject, the subject having received an injection of microbubbles through a fluid, the modulation wave causing the microbubbles to undergo stable acoustic cavitation;
emitting, toward the target and concurrently with the modulation wave, ultrasound imaging pulses centered at a frequency F 2 and having a pulse repetition period of n*P 1 and a pulse delay of m*P 1 /k, where the pulse delay varies with m, m<k, and k>1, and where n and k are defined to synchronize the ultrasound imaging pulses with the continuous modulation wave by positioning each ultrasound imaging pulse within a given cycle of the continuous modulation wave;
detecting reflections of the ultrasound imaging pulses by the microbubbles after each emission for a duration corresponding to a maximum depth of the target;
forming ultrasound images from the reflections to determine, based on the ultrasound images, a location of the treatment beam in real-time;
displaying the ultrasound images as the treatment beam is applied; and
adjusting the location of the treatment beam based on the ultrasound images.

Assignees

• Polyvalor Lp
• Corp De Lecole Polytechnique De Montreal

Inventors

• Blais Simon
• Poree Jonathan
• Provost Jean

Classifications

• A61N2007/0039

  using microbubbles · CPC title

• A61N7/02

  Localised ultrasound hyperthermia · CPC title

• A61B8/461

  Displaying means of special interest · CPC title

• G01S7/52022

  using a sequence of pulses, at least one pulse manipulating the transmissivity or reflexivity of the medium · CPC title

• G01S7/52039

  exploiting the non-linear response of a contrast enhancer, e.g. a contrast agent (diagnostic techniques involving the use of contrast agents A61B8/481) · CPC title