SYSTEM AND METHOD FOR TISSUE CHANGE MONITORING DURING HIFU TREATMENT

• US 20090069677A1
• Filed: 09/11/2007
• Published: 03/12/2009
• Est. Priority Date: 09/11/2007
• Status: Active Grant

• Current Assignee: Focus Surgery, Inc. (Sonacare Medical, LLC)
• Original Assignee: Focus Surgery, Inc. (Sonacare Medical, LLC)
• Inventors: WEIS, CLINT C., CARLSON, ROY, SEIP, RALF, CHEN, WO-HSING, SANGHVI, NARENDRA T.
• Granted Patent: US 8,235,902 B2
• Time in Patent Office: Days
• US Class Current: 600/439
• CPC Class Codes: A61B 2090/378 using ultrasound
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00

Abstract

A method and apparatus is disclosed for determining the presence of tissue change due to exposure to HIFU Therapy.

Claims

1. An apparatus for treating tissue in a treatment region, the apparatus comprising:

a transducer which is positionable proximate to the tissue, the transducer being configured to emit ultrasound energy and to receive ultrasound energy;

a positioning member coupled to the transducer and configured to position the transducer; and

a controller operably coupled to the transducer and to the positioning member, the controller being configured to position the transducer with the positioning member and to operate the transducer in an imaging mode wherein images of the tissue in the treatment region are obtained from ultrasound energy sensed by the transducer and in a therapy mode wherein a plurality of treatment sites are treated with a HIFU Therapy with the transducer;

the controller being further configured to monitor a plurality of regions of interest in the treatment region and to determine a tissue change value for each region of interest based on a frequency analysis of at least two images of the plurality of images, each region of interest corresponding to a multi-dimensional portion in each of the at least two images.

2. The apparatus of claim 1, wherein the imaging mode and the therapy mode are separately performed.

3. The apparatus of claim 2, wherein a first image is acquired in a first imaging mode, the first image including a first region of interest;

a first HIFU Therapy is directed at a first treatment site in a first therapy mode, the first treatment site positioned within the first region of interest; and

a second image is acquired in a second imaging mode, the second image including the first region of the interest, the first therapy mode being later in time than the first imaging mode and the second imaging mode being later in time than the first therapy mode.

4. The apparatus of claim 3, wherein the controller is further configured to determine a first power spectrum for the first region of interest based on the first image and a second power spectrum for the first region of interest based on the second image, each of the first power spectrum and the second power spectrum including a plurality of frequency bands, the tissue change value being determined based on a comparison of the plurality of frequency bands of the first power spectrum and the second power spectrum.

5. The apparatus of claim 3, further comprising a display for displaying the second image and a visual indicator of the tissue change value overlaying the second image at a location corresponding to the first treatment site.

6. The apparatus of claim 3, further comprising a display for displaying a three-dimensional image of the treatment region and a visual indicator of the tissue change value positioned within the three-dimensional image at a location corresponding to the first treatment site.

7. The apparatus of claim 5, wherein the visual indicator has a color which is associated with a level that the tissue change value is within.

8. A method of providing treatment to a treatment region of tissue, the method comprising the steps of:

acquiring a first image including a treatment site prior to a direct treatment with a HIFU Therapy, the first image being at least a multi-dimensional image;

performing the direct treatment of the treatment site with the HIFU Therapy;

acquiring a second image including the treatment site subsequent to the direct treatment, the second image being a multi-dimensional image; and

determining a tissue change value in a region of interest of the tissue based on a first power spectrum of a portion of the first image corresponding to the region of interest and a second power spectrum of a portion of the second image corresponding to the region of interest, the region of interest including the treatment site.

9. The method of claim 8, wherein the first image and the second image each are two-dimensional images having a plurality of one-dimensional echo lines, the portion of the first image corresponding to the region of interest includes a portion of a subset of the one-dimensional echo lines corresponding to a focal zone including the treatment site and the portion of the second image corresponding to the region of interest includes the portion of the subset of the one-dimensional echo lines corresponding to the focal zone including the treatment site.

10. The method of claim 9, wherein the step of determining a level of tissue change in a region of interest of the tissue includes the steps of:

determining the first power spectrum of the portion of the first image corresponding to the region of interest;

determining the second power spectrum of the portion of the second image corresponding to the region of interest;

for each of a plurality of frequency bands comparing the corresponding portions in the first power spectrum and the second power spectrum;

determining a first frequency band from the plurality of frequency bands which has the largest difference between the first power spectrum and the second power spectrum, the indication of the tissue change corresponding to the largest difference.

11. The method of claim 8, wherein in the indication is a level of the tissue change.

12. The method of claim 11, further comprising the step of providing a visual indication of the level on a display, the visual indication being overlaid on an image of the treatment region in a position corresponding to the region of interest and the visual indication having a color associated with the level of tissue change.

13. The method of claim 8, wherein the first image corresponds to a state of the treatment site prior to the direct treatment of the treatment site with the HIFU Therapy.

14. The method of claim 8, wherein the first image corresponds to a state of the treatment site prior to the direct treatment of the treatment site with the HIFU Therapy and prior to an earlier direct treatment of a proximate treatment site with the HIFU Therapy.

15. The method of claim 8, wherein an additional direct treatment of the treatment site is performed based on the indication of the tissue change being below a threshold.

16. A method of providing treatment to a treatment region of tissue, the method comprising the steps of:

monitoring a level of a tissue change in a region of interest of the treatment region due to an indirect treatment of the tissue in the region of interest in response to a direct treatment of at least one treatment sites with the HIFU Therapy in the treatment region outside of the region of interest, the level of the tissue change being determined by a comparison of the power spectrums of at least two images including the region of interest; and

determining whether to provide a direct treatment with the HIFU Therapy to a treatment site within the region of interest based on the level of the tissue change.

17. The method of claim 16, wherein if the level of the tissue change is below a threshold then the treatment site within the region of interest is provided a direct treatment with the HIFU Therapy.

18. The method of claim 16, wherein if the level of the tissue change is above a threshold then the treatment site within the region of interest is skipped.

19. A method of providing treatment to a treatment region of tissue, the method comprising the steps of:

performing acquiring a first image including a treatment site prior to a direct treatment with a HIFU Therapy, the first image being a multi-dimensional image;

performing the direct treatment of the treatment site with the HIFU Therapy;

acquiring a second image including the treatment site subsequent to the direct treatment, the second image being a multi-dimensional image;

determining an indication of a tissue change in a region of interest of the tissue from a frequency domain analysis of the first image and the second image; and

providing a color-coded visual indicator on an image of the treatment region, the color-coded visual indicator providing an indication of a degree of tissue change.

20. The method of claim 19, further comprising the step of altering the subsequent treatment of tissue in the treatment region based on the degree of tissue change.

21. The method of claim 19, wherein the image is a B-mode echo image and wherein the tissue change indicated by the color-coded visual indicator is visually invisible in the B-mode echo image.

22. The method of claim 19, further comprising the steps of;

determining a second indication of a tissue change in a second region of interest; and

abandoning the provision of a direct HIFU Therapy to a second treatment site located in the second region of interest based on the second indication satisfying a threshold.

23. The method of claim 22, wherein the second indication is determined based on at least one image other than the first image and the second image.

24. A method of providing treatment to a treatment region of tissue, the method comprising the steps of:

performing acquiring a first image including a treatment site and a region outside of the region of interest prior to a direct treatment with a HIFU Therapy, the first image being a multi-dimensional image;

performing the direct treatment of the treatment site with the HIFU Therapy;

acquiring a second image including the treatment site and the region of outside of the region of the interest to the direct treatment, the second image being a multi-dimensional image;

determining an indication of a tissue change in the region outside of the region of interest from a frequency domain analysis of the first image and the second image; and

providing a color-coded visual indicator on an image of the region outside of the region of the interest, the color-coded visual indicator providing an indication of a degree of tissue change.

25. The method of claim 24, further comprising the step of altering the subsequent treatment of tissue in the treatment region based on the degree of tissue change in the outside of the region of the interest.