Methods and apparatus for imaging with magnetic induction

• US 9,411,033 B2
• Filed: 05/10/2006
• Issued: 08/09/2016
• Est. Priority Date: 05/11/2005
• Status: Active Grant

• Current Assignee: Regents of The University of Minnesota (University of Minnesota)
• Original Assignee: Regents of The University of Minnesota (University of Minnesota)
• Inventors: He, Bin, Xu, Yuan, Li, Xu
• Primary Examiner(s): Roy, Baisakhi
• Application Number:
  US11/913,894
• Publication Number:
  US 20090018432A1
• Time in Patent Office: 3,744 Days
• Field of Search: 600/437, 600/547, 600/558, 735/79
• US Class Current: 1/1
• CPC Class Codes: A61B 5/0093 Detecting, measuring or recording by applying one single type of energy and measuring its conversion into another type of energy
• CPC Class Codes: A61B 8/00 Diagnosis using ultrasonic, sonic or infrasonic waves imaging of objects using sonar G01S15/00
• CPC Class Codes: G01R 33/4808 Multimodal MR, e.g. MR combined with positron emission tomography [PET], MR combined with ultrasound or MR combined with computed tomography [CT]

Abstract

An apparatus includes a magnetic energy source to provide a magnetic signal and a detector to detect an acoustic energy signal from a sample stimulated by the magnetic energy signal. A method includes applying a magnetic signal to a biological sample, detecting an acoustic signal from the sample, and processing the acoustic signal to determine the electrical impedance distribution of the sample, and identify disease in the biological sample. A method includes applying a magnetic signal to a sample, detecting a magnetic or electrical signal within the sample, and processing the magnetic or electrical signal to reconstruct electrical impedance distribution of the sample.

Claims

1. An apparatus comprising:

a magnetic energy source configured to provide a static magnetic field oriented along a direction and a magnetic signal that induces electrical currents in a sample, the magnetic signal being oriented along the same direction as the static magnetic field;

a detector configured to detect an acoustic energy signal that is produced in response to forces generated by a combination of the induced electrical currents and the static magnetic field; and

a computer to process the acoustic energy signal to;

determine an electrical impedance distribution of the sample;

produce an electrical impedance image that depicts the determined electrical impedance distribution of the sample;

display the electrical impedance image in a displaying device, in conjunction with other anatomic imaging results; and

identify cancer from impedance contrast in the electrical impedance distribution of the sample.

2. The apparatus of claim 1, wherein the magnetic signal includes a non-static magnetic signal.

3. The apparatus of claim 2, wherein the non-static magnetic signal includes a pulsed magnetic signal.

4. A method comprising:

positioning a sample in a static magnetic field that is oriented along a direction;

applying a magnetic signal to the sample to induce electrical currents in the sample, the magnetic signal being applied in the same direction along which the static magnetic field is oriented;

detecting an acoustic signal from the sample that is formed in response to forces generated in the sample by a combination of the induced electrical currents and the static magnetic field;

processing the acoustic signal to form an image of an electrical property distribution in the sample; and

displaying the electrical property image in a displaying device, in conjunction with other anatomic imaging results; and

identifying cancer from a contrast in the image of the electrical property distribution in the sample.

5. The method of claim 4, wherein applying a magnetic signal to a sample includes applying a non-static magnetic field to the sample.

6. The method of claim 4, wherein the electrical property distribution is an electrical impedance distribution and processing the acoustic signal to form the image of the electrical property distribution in the sample includes processing the acoustic signal to determine the electrical impedance distribution in the sample and forming the image as an image that depicts the determined electrical impedance distribution in the sample.

7. The method of claim 4, wherein the electrical property distribution is an eddy current distribution and processing the acoustic signal to form the image of the electrical property distribution in the sample includes processing the acoustic signal to determine the eddy current distribution in the sample and forming the image as an image that depicts the determined eddy current distribution in the sample.

8. A method comprising:

positioning a biological sample in a static magnetic field that is oriented along a direction;

applying a magnetic signal to the biological sample to induce electrical currents in the biological sample, the magnetic signal being applied in the same direction along which the static magnetic field is oriented;

detecting an acoustic signal from the biological sample that is formed in response to forces generated in the biological sample by a combination of the induced electrical currents and the static magnetic field;

processing the acoustic signal to determine an electrical impedance distribution of the biological sample;

producing an electrical impedance image that depicts the determined electrical impedance distribution of the biological sample; and

identifying disease from impedance contrast in the electrical impedance distribution of the biological sample.

9. A method comprising,

positioning a biological sample in a static magnetic field that is oriented along a direction;

applying a magnetic signal to the biological sample to induce electrical currents in the biological sample, the magnetic signal being applied in the same direction along which the static magnetic field is oriented;

detecting an acoustic signal from the biological sample;

that is formed in response to forces generated in the biological sample by a combination of the induced electrical currents and the static magnetic field; and

processing the acoustic signal to determine an electrical impedance distribution of the biological sample;

producing an electrical impedance image that depicts the determined electrical impedance distribution of the biological sample; and

displaying the electrical impedance image in a displaying device, in conjunction with other anatomic imaging results to aid detecting and diagnosing of cancer based on an impedance contrast in the electrical impedance distribution of the biological sample.

10. A method comprising:

positioning a biological sample in a static magnetic field that is oriented along a direction;

applying a magnetic signal to the biological sample to induce electrical currents in the biological sample, the magnetic signal being applied in the same direction along which the static magnetic field is oriented;

detecting an acoustic signal from the biological sample that is formed in response to forces generated in the biological sample by a combination of the induced electrical currents and the static magnetic field;

processing the acoustic signal to determine an electrical impedance distribution of the biological sample;

producing an electrical impedance image that depicts the determined electrical impedance distribution of the biological sample; and

displaying the electrical impedance image in a displaying device, in conjunction with other anatomic imaging results for applications in arrhythmia management.

11. A method comprising:

positioning a neurological sample in a static magnetic field that is oriented along a direction;

applying a magnetic signal to the neurological sample to induce electrical currents in the neurological sample, the magnetic signal being applied in the same direction along which the static magnetic field is oriented;

detecting an acoustic signal from the neurological sample that is formed in response to forces generated in the neurological sample by a combination of the induced electrical currents and the static magnetic field;

processing the acoustic signal to determine an electrical impedance distribution of the biological sample;

producing an electrical impedance image that depicts the determined electrical impedance distribution of the biological sample; and

displaying the electrical impedance image in a displaying device, in conjunction with other anatomic imaging results to determine functions and dysfunctions in the neurological sample based on an impedance contrast in the electrical impedance distribution of the biological sample.

12. A method comprising:

positioning a sample in a static magnetic field;

applying a magnetic signal to the sample to induce electrical currents in the sample;

detecting an acoustic signal from the sample that is formed in response to forces generated in the sample by a combination of the induced electrical currents and the static magnetic field;

processing the acoustic signal to determine an electrical impedance distribution of the sample;

producing an electrical impedance image that depicts the determined electrical impedance distribution of the sample;

displaying the electrical impedance image in a displaying device, in conjunction with other anatomic imaging results; and

identifying cancer from impedance contrast in the electrical impedance distribution of the sample.

13. An apparatus comprising:

a magnetic energy source to provide;

a static magnetic field that is oriented along a direction; and

a magnetic signal that is oriented along the same direction as the static magnetic field and that induces electrical currents in a sample including human breast tissue;

a detector to detect an acoustic energy signal that is produced in response to forces generated by a combination of the induced electrical currents and the static magnetic field; and

a computer to process the acoustic energy signal to;

determine an electrical impedance distribution in the human breast tissue;

produce an electrical impedance image that depicts the determined electrical impedance distribution in the human breast tissue, and

identify cancer from impedance contrast in the electrical impedance distribution of the human breast tissue.

14. A method comprising:

positioning a sample in a static magnetic field that is oriented along a direction;

applying a magnetic signal to the sample to induce electrical currents in the sample, the magnetic signal being applied in the same direction along which the static magnetic field is oriented;

detecting an acoustic signal from the sample that is formed in response to forces generated in the sample by a combination of the induced electrical currents and the static magnetic field;

processing the acoustic signal to derive a current density distribution for the sample;

producing a current density image that depicts the current density distribution for the sample; and

displaying the current density image in a displaying device in conjunction with other anatomic imaging results, to aid detecting and diagnosing of cancer.

15. A method comprising:

positioning a sample in a static magnetic field that is oriented along a direction;

applying a magnetic signal to the sample to induce electrical currents in the sample, the magnetic signal being applied in the same direction along which the static magnetic field is oriented;

detecting an acoustic signal from the sample that is formed in response to forces generated in the sample by a combination of the induced electrical currents and the static magnetic field;

processing the acoustic signal to derive a conductivity value for the sample;

producing an conductivity image that depicts the conductivity value for the sample; and

displaying the conductivity image in a displaying device, in conjunction with other anatomic imaging results, to aid detecting and diagnosing of cancer.

16. A method comprising:

positioning a sample in a static magnetic field that is oriented along a direction;

applying a magnetic signal to the sample to induce electrical currents in the sample, the magnetic signal being applied in the same direction along which the static magnetic field is oriented;

detecting an acoustic signal from the sample that is formed in response to forces generated in the sample by a combination of the induced electrical currents and the static magnetic field;

processing the acoustic signal to identify one or more locations of conductivity change in the sample;

producing an image that depicts the one or more locations of conductivity change in the sample; and

displaying the image in a displaying device, in conjunction with other anatomic imaging results, to aid detecting and diagnosing of cancer.

17. A method comprising:

positioning a sample in a static magnetic field;

applying a magnetic signal to the sample to induce electrical currents in the sample;

detecting an acoustic signal from the sample that is formed in response to forces generated in the sample by a combination of the induced electrical currents and the static magnetic field; and

processing the acoustic signal to determine an eddy current distribution in the sample;

processing the acoustic signal to determine a combined current distribution in the sample, the combined current distribution representing the eddy current distribution in the sample and a biological current distribution in the sample; and

subtracting the eddy current distribution from the combined current distribution to determine the biological current distribution in the sample.