Shear Wave Imaging Method and Installation for Collecting Information on a Soft Solid

Patent metadata

Field	Value
Publication number	US-2016367143-A1
Application number	US-201414903876-A
Country	US
Kind code	A1
Filing date	Jul 10, 2014
Priority date	Jul 11, 2013
Publication date	Dec 22, 2016
Grant date	—

Abstract

This shear wave imaging method, for collecting information on a target region (R) of a soft solid (S), comprises at fi least the steps a) of generating at least one shear wave (SW) in the target region, and b) of detecting a propagation pattern of the shear wave in the target region. Step a) is realized by applying to particles of the target region (R) some Lorentz forces resulting from an electric field (E) and from a magnetic field (B). At least one of the electric field (E) and the magnetic field (B) is variable in time, with a central frequency (f o ) between 1 Hz and 10 kHz. Alternatively, both the electric and magnetic fields (E, B) are variable in time, with a central difference frequency (Δf o ) between 1 Hz and 10 kHz. The shear wave imaging installation comprises a first system ( 4, 7 ) for generating at least one shear wave (SW) in the target region (R) and a second system ( 10 ) for detecting a propagation pattern of the shear wave. The first system includes first means ( 4 ) to apply an electric field (E) through the target region (R) and second means ( 7 ) to apply a magnetic field (B) through the target region. The first and second means are configured to apply to particles of the target region some Lorentz forces resulting from the electric field (E) and the magnetic field (B), where at least one of these fields is a quantity variable in time, with a central frequency (f o ) between 1 Hz and 10 kHz, or both fields are quantities variable in time, with a central difference frequency (Δf o ) between 1 Hz and 10 kHz.

First claim

1 . Shear wave imaging method for collecting information on a target region of a soft solid, the method comprising at least the following steps:
a) generating at least one shear wave in the target region, b) detecting a propagation pattern of the at least one shear wave in the target region
characterized in that
step a) is realized by applying to particles of the target region some Lorentz forces resulting from an electric field and from a magnetic field,
at least one of the electric field and the magnetic field is variable in time, with a central frequency between 1 Hz and 10 kHz or both the electric and magnetic fields are variable in time, with a central difference frequency between 1 Hz and 10 kHz.

2 . The method according to claim 1 , wherein during step a), a first one of the electric field and the magnetic field is variable in time and the second one of the electric field and the magnetic field is constant in time.

3 . The method according to claim 2 , wherein during step a), the electric field is variable in time and the magnetic field is constant in time.

4 . The method according to claim 2 , wherein during step a), the magnetic field is variable in time and the electric field is constant in time.

5 . The method according to claim 1 , wherein during step a), both the electric field and the magnetic field are variable in time, at frequencies between 1 and 10 kHz, or both the electric field and the magnetic field are variable in time at high frequencies, with a central difference frequency between 1 Hz and 10 kHz.

6 . The method according to claim 1 , wherein the central frequency of the variable field or the central difference frequency is between 5 and 1000 Hz.

7 . The method according to claim 1 , wherein the electric field is generated by two electrodes located on both sides, on one side or within the soft solid and connected to a source of electric current with an intensity between 1 μA and 1 A.

8 . The method according to claim 1 , wherein the electric field is generated by a second magnetic field, variable in time.

9 . The method according to claim 1 , wherein the soft solid is a biological tissue of human, animal or vegetal origin, preferably an organ, or an artificial medium.

10 . The method according to claim 1 , wherein during step b), measurement of the shear wave propagation speed occurs via a sensor assembly based on ultrasound technology.

11 . The method according to claim 1 , wherein during step b), measurement of the shear wave propagation speed occurs via a sensor assembly based on magnetic resonance imaging (MRI) technology.

12 . The method according to claim 11 , wherein the magnetic field used during step a) is generated by the sensor assembly based on magnetic resonance imaging (MRI) technology.

13 . The method according to claim 1 , wherein during step b) a source of the at least one shear wave is detected.

14 . Shear wave imaging installation for collecting information of a target region of a soft solid, said shear wave imaging installation comprising:
a first system for generating at least one shear wave in the target region a second system for detecting a propagation pattern of the at least one shear wave
characterized in that the first system includes
first means to apply an electric field through the target region and
second means to apply a magnetic field through the target region and in that the first and second means are configured to apply to particles of the target region Lorentz forces resulting from the electric field and the magnetic field, where at least one of the electric field and the magnetic field is a quantity variable in time, with a central frequency (f o ) between 1 Hz and 10 kHz, or both the electric and magnetic fields are quantities variable in time, with a central difference frequency between 1 Hz and 10 kHz.

15 . The installation according to claim 14 , wherein the first means includes a set of electrodes installed on both sides, on one side or within the soft solid and connected to a source of electric current with an intensity between 1 μa and 1 A.

16 . The method of claim 6 , wherein the central difference frequency is between 50 and 150 Hz.

17 . The method of claim 9 , wherein the biological tissue is an organ

Assignees

• Inst Nat De La Sante Et De La Rech Medicale (Inserm)
• Univ Claude Bernard Lyon

Inventors

• Catheline Stefan
• Chapelon Jean-Yves
• Souchon Rémi
• Grasland-Mongrain Pol
• Lafon Cyril

Classifications

• A61B5/055

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

• A61B5/0051 Primary

  by applying vibrations · CPC title

• A61B8/485 Primary

  involving measuring strain or elastic properties · CPC title

• A61B5/0536

  Impedance imaging, e.g. by tomography · CPC title

• G01R33/56358

  Elastography · CPC title