METHODS AND APPARATUS FOR IMAGING WITH MAGNETIC INDUCTION

• US 20090018432A1
• Filed: 05/10/2006
• Published: 01/15/2009
• 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: Li, Xu, Xu, Yuan, He, Bin
• Granted Patent: US 9,411,033 B2
• Time in Patent Office: Days
• US Class Current: 600/409
• 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 to provide a magnetic signal; and

a detector to detect an acoustic energy signal from a sample stimulated by the magnetic energy signal.

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

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

4. An apparatus comprising:

an acoustic energy source to provide an acoustic signal; and

a detector to detect a magnetic energy signal from a sample stimulated by the acoustic signal.

5. A method comprising;

applying a magnetic signal to a sample;

detecting an acoustic signal from the sample; and

processing the acoustic signal to form an image of the sample.

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

7. The method of claim 5, wherein processing the acoustic signal to form the image of the sample includes forming an image of the electrical impedance distribution in the sample.

8. The method of claim 5, wherein processing the acoustic signal to form the image of the sample includes forming an image of the eddy current distribution in the sample.

9. A method comprising:

applying a magnetic signal to a biological sample;

detecting an acoustic signal from the sample; and

processing the acoustic signal to identify disease in the biological sample.

10. A method comprising;

applying a magnetic signal to a biological sample;

detecting an acoustic signal from the sample; and

processing the acoustic signal to aid detecting and diagnosing of cancer.

11. A method comprising:

applying a magnetic signal to a biological sample;

detecting an acoustic signal from the sample; and

processing the acoustic signal for applications in arrhythmia management.

12. A method comprising:

applying a magnetic signal to a neurological sample;

detecting an acoustic signal from the sample; and

processing the acoustic signal to determine functions and disfunctions in the neurological sample.

13. A method comprising:

applying a magnetic signal to a sample;

detecting an acoustic signal from the sample; and

processing the acoustic signal to generate a feedback signal to control the magnetic signal.

14. The method of claim 13, further comprising treating a psychiatric disease by controlling the intensity of the magnetic signal with the feedback signal.

15. A method comprising:

applying an acoustic signal to a biological sample;

detecting a magnetic signal from the sample; and

processing the magnetic signal to identify disease in the biological sample.

16. A method comprising applying an acoustic signal to a biological sample;

detecting a magnetic signal from the sample; and

processing the magnetic signal to aid surgical planning.

17. A method comprising:

applying an acoustic signal to a biological sample;

detecting a magnetic signal from the sample; and

processing the magnetic signal for use in arrhythmia management.

18. A method comprising:

applying an acoustic signal to a neurological sample;

detecting a magnetic signal from the sample; and

processing the magnetic signal to determine functions and disfunctions in the neurological sample.

19. A method comprising:

applying a magnetic signal to a sample;

detecting an acoustic signal from the sample induced by the magnetic signal;

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

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

identifying cancer with impedance contrast.

20. An apparatus comprising:

applying a magnetic signal to a sample;

detecting an acoustic signal from the sample induced by the magnetic signal;

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

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

identifying cancer with impedance contrast.

21. An apparatus comprising:

an imaging system;

a model of an object to be imaged;

a stimulation system to provide a signal to the object; and

a computation unit to generate a conductivity distribution of the object by reducing a difference between a measured signal from the imaging system and a model predicted signal.

22. The apparatus of claim 21, wherein the imaging system includes a magnetic resonance imaging system.

23. The apparatus of claim 21, wherein the stimulation system includes magnetic induction.

24. The apparatus of claim 21, wherein the model includes a piecewise homogeneous model for which conductivity profiles of each homogeneous region are estimated.

25. The apparatus of claim 21, wherein the model includes an inhomogeneous model.

26. The apparatus of claim 21, wherein the computation unit includes an automatic searching algorithm.

27. The apparatus of claim 21, wherein the computation unit includes an artificial neural network.

28. A method comprising:

selecting a threshold value;

decreasing a difference between a measured magnetic flux density distribution in an object and a model of a predicted flux density distribution in the object below the threshold value; and

reconstructing a conductivity distribution in the object.

30-34. -34. (canceled)

35. A method comprising:

applying magnetic induction stimulation to an object;

comparing magnetic flux density distribution in the object to a calculated magnetic flux density distribution for a model of the object; and

updating a conductivity distribution of the model until a difference between a measured magnetic flux density distribution and the calculated magnetic flux density distribution is less than a predetermined value.

36. An apparatus comprising:

a magnetic energy source to provide a magnetic signal; and

a detector to detect an acoustic energy signal from a semiconductor sample stimulated by the magnetic energy signal.

38. An apparatus comprising:

a magnetic energy source to provide a magnetic signal; and

a detector to detect an acoustic energy signal from a sample including human breast tissue stimulated by the magnetic energy signal.

40. A method comprising:

applying a magnetic signal to a sample;

detecting an acoustic signal from the sample; and

processing the acoustic signal to derive a Lorentz force for the acoustic signal.

41. A method comprising:

applying a magnetic signal to a sample;

detecting an acoustic signal from the sample; and

processing the acoustic signal to derive a divergence of a Lorentz force for the acoustic signal.

42. A method comprising:

applying a magnetic signal to a sample;

detecting an acoustic signal from the sample; and

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

43. A method comprising:

applying a magnetic signal to a sample;

detecting an acoustic signal from the sample; and

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

44. A method comprising:

applying a magnetic signal to a sample;

detecting an acoustic signal from the sample; and

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

45. A method comprising:

applying a magnetic signal to a sample;

detecting an acoustic signal from the sample; and

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

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

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