Method and system for MRI-based targeting, monitoring, and quantification of thermal and mechanical bioeffects in tissue induced by high intensity focused ultrasound

Patent metadata

Field	Value
Publication number	US-10694974-B2
Application number	US-201515120812-A
Country	US
Kind code	B2
Filing date	Mar 27, 2015
Priority date	Mar 27, 2014
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

Example embodiments of system and method for magnetic resonance imaging (MRI) techniques for planning, real-time monitoring, control, and post-treatment assessment of high intensity focused ultrasound (HIFU) mechanical fractionation of biological material are disclosed. An adapted form of HIFU, referred to as “boiling histotripsy” (BH), can be used to cause mechanical fractionation of biological material. In contrast to conventional HIFU, which cause pure thermal ablation, BH can generate therapeutic destruction of biological tissue with a degree of control and precision that allows the process to be accurately measured and monitored in real-time as well as the outcome of the treatment can be evaluated using a variety of MRI techniques. Real-time monitoring also allow for real-time control of BH.

First claim

We claim:

1. A method comprising:
applying high-intensity focused ultrasound (HIFU) histotripsy to a target volume of biological material;
concurrently with applying the HIFU histotripsy to the target volume, acquiring magnetic resonance imaging (MRI) data from the target volume;
identifying a first feature of the MRI data as corresponding to mechanically fractionated biological material within the target volume;
identifying a second feature of the MRI data as corresponding to intact biological material within the target volume; and
adjusting application of the HIFU histotripsy to cause mechanical fractionation of the intact biological material by at least one of: (i) adjusting a spatial location of a focal point of the HIFU histotripsy, (ii) adjusting a duration of the HIFU histotripsy, (iii) adjusting HIFU pulse parameters, (iv) adjusting HIFU pulse power, or (v) adjusting HIFU pulse duty cycle,
wherein applying the HIFU histotripsy to the target volume comprises applying boiling histotripsy (BH) to the target volume,
wherein acquiring the MRI data comprises: acquiring one or more MRI thermal-metric maps of the target volume, wherein each of the one or more MRI thermal-metric maps is one of an MRI temperature map or an MRI thermal dose map, and
wherein acquiring the one or more MRI thermal-metric maps comprises:
acquiring a time sequence of multiple MRI thermal-metric maps during a time interval that is concurrent with applying the HIFU histotripsy, the method further comprising:
monitoring spatial and temporal progress of HIFU-histotripsy-induced mechanical fractionation of the target volume by:
determining a thermal-property distribution within the target volume for each of the multiple MRI thermal-metric maps of the time sequence, wherein the thermal-property distribution is one of a temperature distribution, a temperature gradient, a thermal-dose distribution, or a thermal-dose gradient; and
comparing the thermal-property distribution in an MRI thermal-metric map at each time in the time sequence of the multiple MRI thermal-metric maps with the thermal-property distributions in one or more of the multiple MRI thermal-metric maps earlier in the time sequence, and determining spatial evolution of HIFU-histotripsy-induced liquefaction of the biological material within the target volume over the time interval.

2. The method of claim 1 , wherein acquiring the MRI data comprises:
acquiring one or more MRI renderings of the target volume.

3. The method of claim 2 , wherein each of the one or more MRI renderings is one of: (i) a diffusion-weighted image, (ii) a T1-weighted image, (iii) a T2-weighted image, (iv) a proton density-weighted image, (v) a T1 map, (vi) a T2 map, (vii) a T1*-weighted image, (viii) a T2*-weighted image, (ix) a T2* map, (x) a T1-p-weighted image, (xi) a fluid attenuated inversion recovery (FLAIR) image, (xii) a susceptibility-weighted image (SWI), (xiii) a diffusion map, or (xiv) a combined MRI rendering of at least two of (i)-(xiii).

4. The method of claim 2 , wherein acquiring the one or more MRI renderings comprises:
acquiring a time sequence of multiple MRI renderings during a time interval that is concurrent with applying the HIFU histotripsy to the target volume, the method further comprising:
based on the acquired MRI data, monitoring spatial and temporal progress of HIFU-histotripsy-induced mechanical fractionation of the target volume by:
comparing contrasting features in an MRI rendering at each time in the time sequence of the multiple MRI renderings with contrasting features in one or more of the multiple MRI renderings earlier in the time sequence, and determining spatial evolution of HIFU-histotripsy-induced mechanical fractionation of the target volume over the time interval.

5. The method of claim 2 , further comprising:
identifying a boundary between the first feature and the second feature as a physical boundary between the mechanically fractionated biological material and the intact biological material.

6. The method of claim 1 , further comprising infusing the target volume with a contrast agent prior to or while acquiring the MRI data.

7. The method of claim 1 , further comprising:
based on the acquired MRI data, controlling subsequent application of the HIFU histotripsy.

8. The method of claim 7 , wherein controlling subsequent application of the HIFU histotripsy comprises:
providing feedback control to application of the HIFU histotripsy according to at least one of an automatic control process or a manual control process.

9. The method of claim 1 , further comprising:
identifying, within the one or more acquired MRI thermal-metric maps, a gradient indicative of a physical boundary between the target volume and a region exterior to the target volume, wherein the gradient is at least one of a temperature gradient or a thermal-dose gradient.

10. The method of claim 1 , further comprising:
based on the one or more acquired MRI thermal-metric maps, controlling subsequent application of the HIFU histotripsy.

11. The method of claim 10 , wherein controlling subsequent application of the HIFU histotripsy comprises:
providing feedback control to application of the HIFU histotripsy according to at least one of an automatic control process or a manual control process.

12. The method of claim 10 , further comprising:
determining a temperature property within the target volume, wherein the temperature property is one of a maximum temperature, a mean temperature, or a median temperature;
when the determined temperature property is no greater than a corresponding threshold temperature property, then continuing applying the HIFU histotripsy within the target volume; and
when the determined temperature property is greater than the corresponding threshold temperature property, then doing one of pausing or discontinuing applying the HIFU histotripsy within the target volume.

13. The method of claim 1 , wherein the biological material is at least one of biological tissue or a biological substance,
wherein the biological tissue is at least one of liver tissue, uterine tissue, kidney tissue, prostate tissue, thyroid tissue, pancreas tissue, brain tissue, nerve tissue, connective tissue, or muscle tissue,
and wherein the biological substance is at least a portion of one of a blood clot or a hematoma.

14. The method of claim 1 , wherein the target volume at least partially overlaps with pathological tissue, the pathological tissue being one of a malignant tumor or benign tumor,
wherein the malignant tumor is one of a glioma, a melanoma, or a carcinoma,
and wherein the benign tumor is one of an adenoma or a fibroid.

15. An apparatus comprising:
a high-intensity focused ultrasound (HIFU) histotripsy subsystem;
a magnetic resonance imaging (MRI) subsystem;
one or more processors;
memory accessible to the one or more processors, and storing instructions that, upon execution by the one or more processors, cause the apparatus to carry out operations including:
applying high-intensity focused ultrasound (HIFU) histotripsy to a target volume of biological material;
concurrently with applying the HIFU histotripsy to the target volume, acquiring magnetic resonance imaging (MRI) data from the target volume;
identifying a first feature of the MRI data as corresponding to mechanically fractionated biological material within the target volume;
identifying a second feature of the MRI data as corresponding to intact biological material within the target volume; and
adjusting application of the HIFU histotripsy to cause mechanical fractionation of the intact

Assignees

• Univ Washington
• Koninklijke Philips Nv

Inventors

• Partanen Ari
• Khokhlova Vera
• Farr Navid
• Lee Donghoon
• Kreider Wayne
• Khokhlova Tatiana
• Maxwell Adam
• Wang Yak-Nam
• Schade George
• Bailey Michael

Classifications

• A61B5/055 Primary

  involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging · CPC title

• A61B5/0036 Primary

  including treatment, e.g., using an implantable medical device, ablating, ventilating · CPC title

• G01R33/4814

  MR combined with ultrasound · CPC title

• G01R33/50

  based on the determination of relaxation times {, e.g. T1 measurement by IR sequences; T2 measurement by multiple-echo sequences} · CPC title

• G01R33/4804

  Spatially selective measurement of temperature or pH · CPC title