Method And Apparatus For Ultrasonic Analysis Of Brain Activity In Stroke Patients

Patent metadata

Field	Value
Publication number	US-2016354061-A1
Application number	US-201615172883-A
Country	US
Kind code	A1
Filing date	Jun 3, 2016
Priority date	Jun 3, 2015
Publication date	Dec 8, 2016
Grant date	—

Abstract

Methods are disclosed comprising transmitting ultrasound waves to a plurality of regions of a brain of a subject via one or more probes, receiving ultrasound echoes corresponding to the transmitted ultrasound waves, determining a parameter based on the ultrasound echoes for each region of the plurality of regions, determining a time course for each parameter, and one or more of: comparing the time courses for each region of the plurality of regions to determine a pulsatility measurement for each region of the plurality of regions and comparing the time courses to one or more of, a known time course in normal brain tissue and a known time course in abnormal brain tissue to classify each region of the plurality of regions as comprising normal brain tissue or abnormal brain tissue.

First claim

What is claimed is:

1 . A method comprising:
transmitting ultrasound waves to a plurality of regions of a brain of a subject via one or more probes; receiving ultrasound echoes corresponding to the transmitted ultrasound waves; determining a parameter based on the ultrasound echoes for each region of the plurality of regions; determining a time course for each parameter; and comparing the time courses for each region of the plurality of regions to determine a pulsatility measurement for each region of the plurality of regions.

2 . The method of claim 1 , further comprising:
comparing the time courses to one or more of, a known time course in normal brain tissue and a known time course in abnormal brain tissue to classify each region of the plurality of regions as comprising normal brain tissue or abnormal brain tissue.

3 . The method of claim 1 , further comprising receiving a signal from an electrocardiogram to determine the timing of a cardiac cycle, and a timing of brain tissue pulsations relative to the cardiac cycle, and differentiating between normal and abnormal brain tissue by comparing pulsations during a certain portion of the cardiac cycle, and/or the delay between the peak of the pulsations to the beginning of the cardiac cycle.

4 . The method of claim 1 , wherein the parameter comprises one or more of, a backscattered intensity, a measure derived from the probability distribution of backscattered intensities from a local brain region, a spectral slope of an instantaneous frequency of each ultrasound echo, a mid-band fit of an instantaneous frequency of each ultrasound echo, a zero-frequency offset of an instantaneous frequency of each ultrasound echo, and a phase shift across different frequencies.

5 . The method of claim 4 , further comprising filtering the backscattered ultrasound echoes through one or more bandpass filters to determine the phase shift across different frequencies.

6 . The method of claim 1 , wherein the known time course in abnormal brain tissue comprises a known time course associated with brain tissue affected by ischemic stroke and a known time course associated with brain tissue affected by hemorrhagic stroke.

7 . The method of claim 1 , further comprising:
accessing a database comprising a plurality of known time courses in the subject; and determining a measure of degree to which the time course has changed over time relative to the plurality of known time courses.

8 . The method of claim 1 , further comprising outputting a composite spatial map of brain tissue pulsatility based on the pulsatility measurements.

9 . The method of claim 1 , further comprising outputting a parametric spatial map indicating whether each region of the plurality of regions is one of, normal, characteristic of ischemic stroke, characteristic of hemorrhagic stroke, or indeterminate.

10 . A method comprising:
transmitting ultrasound waves to a plurality of regions of a brain of a subject via one or more probes; receiving ultrasound echoes corresponding to the transmitted ultrasound waves; determining a parameter based on the ultrasound echoes for each region of the plurality of regions; determining a time course for each parameter; and comparing the time courses to one or more of, a known time course in normal brain tissue and a known time course in abnormal brain tissue to classify each region of the plurality of regions as comprising normal brain tissue or abnormal brain tissue.

11 . The method of claim 10 , further comprising:
comparing the time courses for each region of the plurality of regions to determine a pulsatility measurement for each region of the plurality of regions.

12 . The method of claim 10 , further comprising receiving a signal from an electrocardiogram to determine the timing of a cardiac cycle, and a timing of brain tissue pulsations relative to the cardiac cycle, and differentiating between normal and abnormal brain tissue by comparing pulsations during a certain portion of the cardiac cycle, and/or the delay between the peak of the pulsations to the beginning of the cardiac cycle.

13 . The method of claim 10 , wherein the parameter comprises one or more of, a backscattered intensity, a measure derived from the probability distribution of backscattered intensities from a local brain region, a spectral slope of an instantaneous frequency of each ultrasound echo, a mid-band fit of an instantaneous frequency of each ultrasound echo, a zero-frequency offset of an instantaneous frequency of each ultrasound echo, and a phase shift across different frequencies.

14 . The method of claim 13 , further comprising filtering the backscattered ultrasound echoes through one or more bandpass filters to determine the phase shift across different frequencies.

15 . The method of claim 10 , wherein the known time course in abnormal brain tissue comprises a known time course associated with brain tissue affected by ischemic stroke and a known time course associated with brain tissue affected by hemorrhagic stroke.

16 . The method of claim 10 , further comprising:
accessing a database comprising a plurality of known time courses in the subject; and determining a measure of degree to which the time course has changed over time relative to the plurality of known time courses.

17 . The method of claim 10 , further comprising outputting a composite spatial map of brain tissue pulsatility based on the pulsatility measurements.

18 . The method of claim 10 , further comprising outputting a parametric spatial map indicating whether each region of the plurality of regions is one of, normal, characteristic of ischemic stroke, characteristic of hemorrhagic stroke, or indeterminate.

19 . A system comprising:
one or more ultrasound transducers configured to transmit ultrasound waves to a plurality of regions of an object and receive backscattered ultrasound echoes corresponding to the transmitted ultrasound waves; a processor, coupled to the one or more ultrasound transducers, wherein the processor is configured to,
transmit ultrasound waves to a plurality of regions of a brain of a subject via one or more probes;
receive ultrasound echoes corresponding to the transmitted ultrasound waves;
determine a parameter based on the ultrasound echoes for each region of the plurality of regions;
determine a time course for each parameter; and
compare the time courses for each region of the plurality of regions to determine a pulsatility measurement for each region of the plurality of regions.

20 . The system of claim 19 , wherein the processor is further configured to:
compare the time courses to one or more of, a known time course in normal brain tissue and a known lime course in abnormal brain tissue to classify each region of the plurality of regions as comprising normal brain tissue or abnormal brain tissue.

Assignees

• Univ George Mason

Inventors

• Hecker Joseph
• Sikdar Siddhartha

Classifications

• A61B8/565

  involving data transmission via a network · CPC title

• A61B8/0808

  for diagnosis of the brain · CPC title

• A61B8/488 Primary

  involving Doppler signals · CPC title

• A61B8/02

  Measuring pulse or heart rate · CPC title

• A61B8/5207

  involving processing of raw data to produce diagnostic data, e.g. for generating an image · CPC title