Method and apparatus for imaging and localizing radiation

• US 6,771,802 B1
• Filed: 06/02/2000
• Issued: 08/03/2004
• Est. Priority Date: 04/13/2000
• Status: Expired due to Term

• Current Assignee: CMR Naviscan Corporation (Compania Mexicana de Radiologia CGR SA de CV)
• Original Assignee: Photon Imaging, Inc.
• Inventors: MacDonald, Lawrence R., Patt, Bradley E., Iwanczyk, Jan S.
• Primary Examiner(s): Mehta, Bhavesh M.
• Assistant Examiner(s): Tabatabai, Abolfazl
• Application Number:
  US09/585,585
• Time in Patent Office: 1,523 Days
• Field of Search: 382/128, 382/129, 382/130, 382/131, 382/132, 250/536, 378/430, 378/2, 378/46, 378/90, 378/92, 378/98.4, 378/140, 600/407, 600/474, 600/410, 600/425, 600/436, 600/606, 600/430, 600/437
• US Class Current: 382/128
• CPC Class Codes: A61B 6/4258 for detecting non x-ray radiation, e.g. gamma radiation A61B6/037 takes precedence
• CPC Class Codes: G01T 1/161 Applications in the field of nuclear medicine, e.g. in vivo counting apparatus for radiation diagnosis A61B6/00

Abstract

An imaging probe system includes a portable imaging gamma ray probe and a computer, and is used to locate and examine the distribution of radiation concentrated in animal tissue. The imaging probe system can operate in an imaging mode, a non-imaging mode (simple counting mode), or both simultaneously. The imaging probe system may include smart algorithms that analyze subdivisions of the images and indicate to the user via an audio indicator, a visual indicator, or both, the presence of one or more high-density concentrations of radiation within the image. The determination of such concentrations is governed either spatial resolution requirements of the subdivided image, or based on statistical variations of the cumulative number of particles detected. The imaging probe can also display the count of the detected radioactivity. The frequency of the audio output may be varied in proportion to the count rate and modulating the frequency, volume, phase or stereo panning of the audio output indicates the presence of more than one source in the field of view. By replacing the collimator of the imaging probe, the user is allowed to vary imaging parameters including variable spatial resolution, sensitivity and field of view.

Claims

1. A system to assess a distribution of x-ray, gamma ray, alpha ray or beta ray radiation emanating from radioisotope concentrated in human or animal tissue, the system comprising:

a portable imaging probe for imaging the distribution of x-ray, gamma ray, alpha ray or beta ray radiation emanating from the radioisotope concentrated in said human or animal tissue;

a display device for displaying the image of the distribution of x-ray, gamma ray, alpha ray or beta ray radiation emanating from the radioisotope concentrated in said human or animal tissue; and

an audio device to generate an audio output to indicate a count rate corresponding to the distribution of x-ray, gamma ray, alpha ray or beta ray radiation emanating from the radioisotope concentrated in said human or animal tissue, while the image of the distribution of x-ray, gamma ray, alpha ray or beta ray radiation is being displayed on the display device.

2. The system of claim 1 further comprising:

a computer to process and store the distribution of radiation.

3. The system of claim 2 wherein the portable imaging probe is coupled to the computer via a cable.

4. The system of claim 2 wherein the portable imaging probe is coupled to the computer over a wireless communication medium.

5. The system of claim 2 wherein the portable imaging probe generates image data from the distribution of radiation, and wherein the system further comprises a software program that runs in the computer to process the image data.

6. The system of claim 5 wherein the software program variably segments one or more images represented by the image data.

7. The system of claim 1 wherein the display device displays a count of detected radiation.

8. The system of claim 1 wherein the portable imaging probe includes a collimator to direct the radiation.

9. The system of claim 8 wherein the collimator includes one or more chambers defined by chamber walls to direct the radiation.

10. The system of claim 9 wherein the chamber walls comprise a material having a high atomic number so as to limit septal penetration.

11. The system of claim 9 wherein the collimator has a pin hole aperture defined by the chamber walls.

12. The system of claim 11 wherein the portable imaging probe further includes an extension to couple to the collimator, and wherein the extension has an aperture smaller than the pin hole aperture.

13. The system of claim 8 wherein the collimator includes diverging chamber walls that are diverging in one or two dimensions.

14. The system of claim 8 wherein the collimator includes parallel chamber walls.

15. The system of claim 1 wherein the portable imaging probe includes an imaging sensor to detect the radiation.

16. The system of claim 15 wherein the portable imaging probe further includes a beta detection sensor, wherein the radiation includes gamma rays and beta rays, and wherein the imaging sensor is used to detect the gamma rays and the beta detection sensor is used to detect the beta rays.

17. The system of claim 1 wherein the portable imaging probe includes a packaging, wherein the packaging comprises an inert material.

18. A system to assess a distribution of radiation concentrated in human or animal tissue, the system comprising:

a portable imaging probe capable of imaging the distribution of radiation in said human or animal tissue, said portable imaging probe for application at an exposed surface of a body of a human or animal;

a display device capable of displaying the image of the distribution of radiation;

an audio device to generate an audio output to indicate a count rate of the radiation; and

a second portable imaging probe,

wherein the portable imaging probe and the second portable imaging probe are used to generate X, Y and Z coordinates of a radioactive node, and wherein the X, Y and Z coordinates are used for three-dimensional localization of the radioactive node.

19. A method of assessing a distribution of x-ray, gamma ray, alpha ray or beta ray radiation emanating from radioisotope concentrated in human or animal tissue, the method comprising:

imaging the distribution of x-ray, gamma ray, alpha ray or beta ray radiation emanating from the radioisotope concentrated in said human or animal tissue using a portable imaging probe;

displaying the image of the distribution of x-ray, gamma ray, alpha ray or beta ray radiation emanating from the radioisotope concentrated in said human or animal tissue; and

generating an audio output to indicate a count rate corresponding to the distribution of x-ray, gamma ray, alpha ray or beta ray radiation emanating from the radioisotope concentrated in said human or animal tissue, while displaying the image of the distribution of x-ray, gamma ray, alpha ray or beta ray radiation.

20. The method of assessing a distribution of radiation of claim 19 further comprising:

varying the audio output to indicate sites of interest for measuring and displaying high quality images representative of the distribution of radiation.

21. The method of assessing a distribution of radiation of claim 20 wherein varying the audio output includes varying a tone of the audio output.

22. The method of assessing a distribution of radiation of claim 20 wherein varying the audio output includes varying a phase of the audio output.

23. The method of assessing a distribution of radiation of claim 20 wherein varying the audio output includes varying an intensity of the audio output.

24. The method of assessing a distribution of radiation of claim 20 wherein varying the audio output includes varying a stereo distribution of the audio output.

25. The method of assessing a distribution of radiation of claim 19 further comprising:

varying the audio output to indicate presence of one or more foci.

26. The method of assessing a distribution of radiation of claim 25 wherein varying the audio output includes varying a tone of the audio output.

27. The method of assessing a distribution of radiation of claim 25 wherein varying the audio output includes varying a phase of the audio output.

28. The method of assessing a distribution of radiation of claim 25 wherein varying the audio output includes varying an intensity of the audio output.

29. The method of assessing a distribution of radiation of claim 25 wherein varying the audio output includes varying a stereo distribution of the audio output.

30. The method of assessing a distribution of radiation of claim 19 further comprising:

using the image and the audio output to localize one or more sources of radiation.

31. The method of assessing a distribution of radiation of claim 19 further comprising:

displaying the count rate of the radiation.

32. The method of assessing a distribution of radiation of claim 19 further comprising processing the distribution of radiation to identify local concentrations of radiation.

33. The method of assessing a distribution of radiation of claim 32 wherein processing the distribution of radiation to identify local concentrations of radiation includes identifying regions of interest within the distribution of radiation.

34. The method of assessing a distribution of radiation of claim 33 wherein processing the distribution of radiation to identify local concentrations of radiation further includes entering input parameters to be used during the identification of the regions of interest.

35. The method of assessing a distribution of radiation of claim 33 wherein processing the distribution of radiation to identify local concentrations of radiation further includes evaluating each of the regions of interest to qualify it as a local concentration of radiation.

36. The method of assessing a distribution of radiation of claim 35 wherein each of the regions of interest is qualified as a local concentration of radiation when a standard deviation of the activity of the region of interest is below a predetermined value.

37. The method of assessing a distribution of radiation of claim 35 wherein each of the regions of interest is qualified as a local concentration of radiation when a ratio of an activity in the region of interest to a background activity is above a predetermined value.

38. The method of assessing a distribution of radiation of claim 32 wherein processing the distribution of radiation to identify local concentrations of radiation includes image preprocessing, the image preprocessing including processing the distribution of radiation to generate the image using triangulation techniques.

39. The method of assessing a distribution of radiation of claim 38 wherein processing the distribution of radiation to generate the image includes generating a raw image using the distribution of radiation.

40. The method of assessing a distribution of radiation of claim 39 wherein processing the distribution of radiation to generate the image further includes converting the raw image into the image using one or more processing tools.

41. The method of assessing a distribution of radiation of claim 38 wherein processing the distribution of radiation to identify local concentrations of radiation further includes calculating a statistical quality of the image.

42. The method of assessing a distribution of radiation of claim 38 wherein processing the distribution of radiation to identify local concentrations of radiation further includes subdividing the image.

43. The method of assessing a distribution of radiation of claim 42 wherein subdividing the image includes generating a lower resolution image.

44. The method of assessing a distribution of radiation of claim 43 wherein a resolution to which the image is reduced is determined on the basis of default parameters.

45. The method of assessing a distribution of radiation of claim 43 wherein a resolution to which the image is reduced is determined on the basis of parameters calculated using the image.

46. The method of assessing a distribution of radiation of claim 43 wherein a resolution to which the image is reduced is determined on the basis of user specified parameters.

47. The method of assessing a distribution of radiation of claim 42 wherein processing the distribution of radiation to identify local concentrations of radiation further includes image thresholding.

48. The method of assessing a distribution of radiation of claim 47 wherein image thresholding includes identifying regions of interest in the subdivided image using one or more pattern recognition algorithms.

49. The method of assessing a distribution of radiation of claim 47 wherein image thresholding includes incrementing a subdivision size when one or more regions of interest do not qualify as a local concentration of radiation using a current subdivision size.

50. The method of assessing a distribution of radiation of claim 47 wherein image thresholding includes using a new threshold value when one or more regions of interest do not qualify as a local concentration of radiation using a current threshold value.

51. The method of assessing a distribution of radiation of claim 19 wherein imaging the distribution of radiation includes using the portable imaging probe to scan said human or animal tissue in search of regions of interest.

52. The method of assessing a distribution of radiation of claim 51 wherein using the portable imaging probe to scan said human or animal tissue in search of regions of interest includes scanning the animal tissue in search of a sentinel node.

53. The method of assessing a distribution of radiation of claim 19 wherein generating and displaying an image includes generating a statistically significant video from low statistic image data.

54. The method of assessing a distribution of radiation of claim 53 wherein generating a statistically significant video includes generating interpolation frames, the interpolation frames being mixture between previously generated images and newly generated images.