Using reflected shear waves for monitoring lesion growth in thermal ablations

Patent metadata

Field	Value
Publication number	US-11337673-B2
Application number	US-201716306938-A
Country	US
Kind code	B2
Filing date	Jun 5, 2017
Priority date	Jun 10, 2016
Publication date	May 24, 2022
Grant date	May 24, 2022

Abstract

A system for boundary identification includes a memory (42) to store shear wave displacements through a medium as a displacement field including a spatial component and a temporal component. A directional filter (206, 208) filters the displacement field to provide a directional displacement field. A signal processing device (26) is coupled to the memory to execute a boundary estimator (214) to estimate a tissue boundary in a displayed image based upon a history of the directional displacement field accumulated over time.

First claim

The invention claimed is:

1. A system for boundary identification, comprising:
a memory configured to store shear wave displacements through a medium as a displacement field including a spatial component and a temporal component;
two directional filters configured to filter the displacement field to provide directional displacement fields; and
a signal processing device coupled to the memory, the memory having instructions stored therein that when executed by the signal processing device cause the signal processing device to estimate a tissue boundary in a displayed image by summing amplitude readings of repeated measurements of propagating waves generated by corresponding push pulses and detected within the directional displacement fields over time and define a spline through amplitude data of the amplitude readings to indicate the tissue boundary, wherein the spline is provided on the displayed image.

2. The system as recited in claim 1 , further comprising an ultrasound probe configured to generate the push pulses configured to generate the shear wave displacements for the displacement field.

3. The system as recited in claim 1 , wherein the two directional filters include a forward propagating filter configured to filter the displacement field to provide a forward propagating displacement field as one of the directional displacement fields.

4. The system as recited in claim 1 , wherein the two directional filters include a backward propagating filter configured to filter the displacement field to provide a backward propagating displacement field as one of the directional displacement fields.

5. The system as recited in claim 1 , wherein the two directional filters include a forward and a backward propagating filter configured to filter the displacement field to provide a forward and backward propagating displacement field as the directional displacement fields.

6. The system as recited in claim 1 , wherein the boundary estimator includes a model to estimate the tissue boundary using a propagating wave field as an input and iteratively solving for reflected waves to minimize error between estimated reflected waves from the model and measured reflected waves using shear wave imaging.

7. The system as recited in claim 1 , wherein the instructions further cause the signal processing device to estimate the tissue boundary based upon pixel clutter indicating a history of shear wave amplitudes.

8. The system as recited in claim 1 , wherein the system includes an ultrasound imaging system having a boundary estimator mode that estimates the tissue boundary in the displayed image when the boundary estimator mode is activated.

9. The system as recited in claim 1 , further comprising:
an ultrasound mode to generate the shear wave displacements using the push pulses through the medium to generate the displacement field, wherein the signal processing device comprises:
a shear wave imaging module configured to detect shear wave displacements for a plurality of tracking positions in the medium to generate the displacement field; and
a data processing module including the two directional filters configured to filter the displacement field to provide the directional displacement fields, the data processing module including the boundary estimator.

10. The system as recited in claim 9 , wherein the instructions further cause the signal processing device to estimate the tissue boundary based upon pixel clutter indicating a history of shear wave amplitudes.

11. The system as recited in claim 9 , wherein the ultrasound mode includes a boundary estimator mode that estimates the tissue boundary in the displayed image when the boundary estimator mode is activated.

12. A method for determining a boundary, comprising:
generating a shear wave displacement field based on a shear wave through a medium;
directionally filtering the shear wave displacement field using a first directional filter and a second directional filter to create directionally propagating displacement fields, wherein the first and second directional filters filter in spatially different directions;
summing amplitude readings of repeated measurements of propagating waves generated by corresponding push pulses and detected within the directionally propagating displacement fields to indicate positions of highest amplitude in an image to identify a tissue boundary in the image;
defining a spline through amplitude data of the amplitude readings to indicate the tissue boundary; and
displaying the spline on the image.

13. The method as recited in claim 12 , wherein the highest amplitude and/or an average of the highest amplitude is displayed on the image.

Assignees

• Koninklijke Philips Nv

Inventors

• Meral Faik Can
• Sethuraman Shriram
• Yan Pingkun
• Shi William Tao
• Kruecker Jochen

Classifications

• G01S7/52026

  Extracting wanted echo signals (Doppler systems G01S15/50; Doppler short range imaging systems G01S15/8979) · CPC title

• G01S7/52022

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

• A61B8/085 Primary

  for locating body or organic structures, e.g. tumours, calculi, blood vessels, nodules · CPC title

• G01S7/52042

  determining elastic properties of the propagation medium or of the reflective target (diagnostic techniques involving the measurement of strain A61B8/485) · CPC title

• G16H30/40

  for processing medical images, e.g. editing · CPC title