Method of detecting microbubbles in a vessel

Patent metadata

Field	Value
Publication number	US-2018317886-A1
Application number	US-201715586879-A
Country	US
Kind code	A1
Filing date	May 4, 2017
Priority date	May 4, 2017
Publication date	Nov 8, 2018
Grant date	—

Abstract

The present invention provides a method of detecting microbubbles in a vessel of an affected part, comprising aggregating the microbubbles, acquiring phase-contrast magnetic resonance images and analyzing the phase-contrast magnetic resonance images. Thus, the present invention can detect or monitor the size and location of MBs in vessels of any part of body.

First claim

What is claimed is:

1 . A method of detecting microbubbles in a vessel of an affected part, comprising:
delivering an ultrasonic energy within the affected part to aggregate the microbubbles to form a plurality of aggregated microbubbles; acquiring a phase-contrast magnetic resonance image by a magnetic resonance device; and analyzing the phase-contrast magnetic resonance image to obtain a velocity value of each pixel of a region of interest in the phase-contrast magnetic resonance image, wherein the plurality of aggregated microbubbles is located at a pixel that the velocity value is within the lowest 10%.

2 . The method as claimed in claim 1 , further comprising:
analyzing the phase-contrast magnetic resonance image to obtain a vorticity value of each pixel of the region of interest, wherein the plurality of aggregated microbubbles is located at a pixel that the velocity value is within the lowest 10% and the vorticity value is −0.18 to 0.18.

3 . The method as claimed in claim 1 , wherein the region of interest is an area of the vessel.

4 . The method as claimed in claim 1 , wherein the microbubbles have a diameter of 1-1.5 μm.

5 . The method as claimed in claim 1 , wherein the microbubbles were substantially composed of C 3 F 8 gas or C 5 F 12 droplet core encapsulated by a lipid shell.

6 . The method as claimed in claim 5 , wherein the microbubbles further comprise a drug for treating the affected part.

7 . The method as claimed in claim 1 , wherein the ultrasonic energy has a frequency of 0.83-1.25 MHz and an acoustic pressure of 0.2-0.12 MPa.

8 . The method as claimed in claim 1 , wherein the phase-contrast magnetic resonance image is a plurality of phase-contrast magnetic resonance images in a time sequence.

9 . The method as claimed in claim 8 , further comprising:
calculating a velocity change of each pixel of the region of interest in the plurality of phase-contrast magnetic resonance images, the velocity change is defined as follows:

Velocity



change




(
%
)

=

velocity



value

-

average



velocity



value



during



preFUS

average



velocity



value





during



preFUS

×
100

%

,

wherein preFUS is a time duration before the ultrasonic energy delivered, and a concentration of the microbubbles is equal to (the velocity change−A)/B, wherein A is 1 to 1.5 and B is 7.56 to 11.34.

10 . The method as claimed in claim 9 , wherein A is 1.25 and B is 9.45.

11 . The method as claimed in claim 8 , further comprising:
calculating a temporal velocity standard deviation of each pixel of the region of interest in the plurality of phase-contrast magnetic resonance images, wherein a concentration of the microbubbles is equal to the temporal velocity standard deviation/C, wherein C is 0.04 to 0.06.

12 . The method as claimed in claim 11 , wherein C is 0.05.

13 . The method as claimed in claim 8 , further comprising:
calculating a temporal velocity standard deviation of each pixel of the region of interest in the plurality of phase-contrast magnetic resonance images; and calculating a range of temporal velocity standard deviation which is 90th percentile of the temporal velocity standard deviation minus 10th percentile of temporal velocity standard deviation, wherein a concentration of the microbubbles is equal to (the range of temporal velocity standard deviation−D)/E, and D is 0.0136 to 0.0204 and E is 0.0856 to 0.1284.

14 . The method as claimed in claim 13 , wherein D is 0.017 and E is 0.107.

Assignees

• Univ Nat Tsing Hua

Inventors

• Peng Hsu-Hsia
• Wu Che-Wei

Classifications

• G06T7/0012

  Biomedical image inspection · CPC title

• A61K9/5015

  Organic compounds, e.g. fats, sugars · CPC title

• G06T7/11

  Region-based segmentation · CPC title

• A61B8/06

  Measuring blood flow · CPC title

• A61K49/1806

  Suspensions, emulsions, colloids, dispersions · CPC title