Early detection of breast cancer using transillumination

Abstract

Several methods have been developed for improving transillumination devices such that they may be effectively used for breast cancer examinations. Each of the methods involves a particluar technique for reducing scattered light. If light which passes straight through a breast can be distinguished from light which is scattered within the breast, better images can be produced. In addition, biochemical markers have been developed which associate with cancerous tissue and enhance the contrast by absorbing light of specific wavelengths.

Patent number: 4945239
Filing date: Mar 29, 1989
Issue date: Jul 31, 1990
Inventors: Abund O. Wist, Ramendra N. Pandey, Panos P. Fatouros
Assignee: Center for Innovative Technology

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What is claimed is:

1. A transillumination apparatus for the early detection of breast caner, comprising:

a source of nonionizing radiation for producing radiation in a specific frequency range, said nonionizing radiation having an intensity which permits passing through a breast;

an optical receiver for receiving radiation from said source of nonionizing radiation which passes through said breast; and

a biochemical marker associated with cancer cells within said breast which absorbs radiation in said specific frequency range.

2. A transillumination apparatus for the early detection of breast cancer as recited in claim 1 where in said biochemical marker is fluorescein isothiocyanate covalently bonded with human transferrin.

3. A transillumination apparatus for the early detection of breast cancer as recited in claim 1 further comprising collimating means for collimating said radiation produced by said source of non-ionizing radiation into a collimated beam of radiation and scanning means for scanning said collimated beam over said breast.

4. A transillumination apparatus as recited in claim 3 further comprising a pair of pin hole boxes positioned on opposite sides of said breast, a first of said pair of pin hole boxes being positioned between said source of radiation and said breast, a second of said pair of pin hole boxes being positioned between said breast and said optical receiver, each of said pin hole boxes having apertures which permit said collimated beam to pass therethrough.

5. A transillumination apparatus as recited in claim 3 further comprising a pair of matched polarizing filters positioned on opposites sides of said breast, a first of said pair being positioned between said source of radiation and said breast, a second of said pair being positioned between said breast and said optical receiver, said first of said pair of polarizing filters permitting only radiation having a specific plane of polarization to pass through said breast, said second of said pair of polarizing filters permitting only radiation having said specific plane of polarization to impinge on said optical receiver.

6. A transillumination apparatus as recited in claim 3 further comprising a phase conjugated mirror for returning radiation of the same phase as said radiation produced by said source, said collimated beam impinging on said phase conjugated mirror before said returning radiation impinges on said optical receiver.

7. A transillumination apparatus as recited in claim 3 wherein said optical receiver comprises a one or more photodetectors, each of said photodetectors producing an electrical signal which corresponds to the intensity of radiation received after having passed straight through said breast.

8. A transillumination apparatus as recited in claim 7 further comprising compressing means for compressing said electrical signal to a compressed signal having a frequency range compatible with photographic film and exposing means for exposing said photographic film to light having an intensity corresponding to said compressed signal.

9. A transillumination apparatus as recited in claim 8 wherein said exposing means comprises an adapter for receiving said compressed signals and a light emitting diode connected to said adapter, said light emitting diode emitting said light having said intensity corresponding to said compressed signal.

10. A transillumination apparatus as recited in claim 3 wherein said optical receiver comprises photographic film, said photographic film being exposed by non-ionizing radiation which has passed straight through said breast.

11. A transillumination apparatus as recited in claim 3 wherein said optical reservoir comprises a photodetector array having a plurality of photodetectors arranged to receive said collimated beam, and further comprising determining means for determining which photodetector of said plurality of photodetectors said collimated beam is directed towards by said scanning means, activating means for selectively activating said photodetector to receive radiation passing straight through said breast, and displaying means for displaying an image of said breast, said photodetector producing an electrical signal proportional to the intensity of said radiation which passes straight through said breast, said displaying means using said electrical signal to present said image of said breast.

12. A transillumination apparatus as recited in claim 3 further comprising a pair of light shutters and controlling means for controlling the opening and closing of said pair of light shutters, a first light shutter being positioned between said source of non-ionizing radiation and said breast, a second light shutter being positioned between said breast and said optical receiver, said controlling means opening said first light shutter for a first short time period and then closing said first light shutter, said controlling means opening said second light shutter for a second short time period and then closing said second light shutter, said first short time period occurring at a predetermined time interval before said second short time period.

13. A transillumination apparatus as recited in claim 12 wherein said predetermined time interval is equivalent to the time required for said non-ionizing radiation to pass from said first light shutter through said breast to said second light shutter.

14. A transillumination apparatus as recited in claim 13 wherein said controlling means provides pulsed signals to said first and second light shutters for opening and closing said first and second light shutters.

15. A transillumination apparatus as recited in claim 13 wherein said predetermined timed interval is determined from standards which simulate breast tissue.

16. A transillumination apparatus for the early detection of breast cancer as recited in claim 1 wherein said source emits a divergent beam of radiation and said optical receiver comprises a photodetector array having a plurality of photodetectors, and further comprising a pulsing means for pulsing said source of non-ionizing radiation to emit pulses of radiation and distinguishing means for distinguishing first arriving radiation from later arriving radiation at each of said photodetectors in said array, said first arriving radiation being the radiation which arrives at said photodetector first after said pulse and said later arriving radiation being the radiation which arrives at said photodetector after said first arriving radiation.

17. A transillumination apparatus for the early detection of breast cancer as recited in claim 1 wherein said source is a laser diode which emits a plurality of collimated beams of radiation and said optical receiver comprises a photodetector array having a plurality of photodetectors, each of said collimated beams from said laser diode being aimed at specific photodetectors in said array.

18. A transillumination apparatus as recited in claim 1 wherein said source emits a divergent beam of radiation and said optical receiver comprises a photodetector array having a plurality of photodetectors, and further comprising pulsing means for pulsing said source to emit pulses of non-ionizing radiation and activating means for selectively activating each of said photodetectors in said array to receive radiation which has passed straight through said breast.

19. A transillumination apparatus as recited in claim 1 wherein said source is a laser diode which emits a plurality of collimated beams of radiation and said optical receiver comprises a photodetector array having a plurality of photodetectors, and further comprising pulsing means for pulsing said laser diode to emit pulses of non-ionizing radiation and activating means for selectively activating each of said photodetectors in said array to receive radiation which has passed straight through said breast.

20. A transillumination apparatus as recited in claim 1 wherein said optical receiver comprises a photodetector array with a plurality of photodetectors, and further comprising first and second phase plates, said first phase plate being positioned between said source and said breast, said second phase plate being positioned between said breast and said photoedetector array, said first phase plate polarizing said non-ionizing radiation before it impinges on said breast, said second phase plate permitting only light having a plane of polarization matched to the light impinging on said breast to pass therethrough to said photodetector array.

21. A transillumination apparatus as recited in claim 20 wherein said first and second phase plates are identical, each of said phase plates having a plurality of sections, each of said sections being ninety degrees out of phase with adjacent sections.

22. A transillumination apparatus as recited in claim 20 wherein said first and second phase plates are not identical, each of said phase plates having a plurality of sections, each of said sections being ninety degrees out of phase with adjacent sections.

23. A transillumination apparatus as recited in claim 1 wherein said optical receiver comprises photographic film, and further comprising a semi-permeable mirror positioned between said source of non-ionizing radiation and said breast, said semi-permeable mirror dividing said non-ionizing radiation into a sample beam and a reference beam, said sample beam being directed through said breast before impinging on said photographic film, said reference beam being directed to said photographic film without passing through said breast.

24. A transillumination apparatus for the early detection of breast caner, comprising:

a source of non-ionizing radiation for producing nonionizing radiation of sufficient intensity to pass through a breast;

an optical receiver for receiving radiation from said source of nonionizing radiation which passes through said breast;

a first polarizing means positioned between said source and said breast for polarizing said nonionizing radiation before it impinges on said breast; and

a second polarizing means matched with said first polarizing means positioned between said breast and said optical receiver for permitting only radiation having a polarity matched to the radiation produced by said first polarizing means to impinge on said optical receiver.

25. A transillumination apparatus as recited in claim 24 wherein said source of non-ionizing radiation produces a collimated beam of radiation which is scanned over said breast, said optical receiver detecting said collimated beam as it is scanned over said breast.

26. A transillumination apparatus as recited in claim 25 wherein said optical receiver comprises a photodetector array with a plurality of photodetectors, each of said photodetectors producing an electrical signal which corresponds to the intensity of received radiation.

27. A transillumination apparatus as recited in claim 25 wherein said optical receiver comprises photographic film, said photographic film being exposed by non-ionizing radiation which has passed straight through the breast.

28. A transillumination apparatus for the early detection of breast caner, comprising:

a source of non-ionizing radiation for producing nonionizing radiation of sufficient intensity to pass through a breast;

an optical receiver for receiving radiation from said source of nonionizing radiation which passes through said breast; and

first and second phase plates having a plurality of polarized sections with adjacent sections being out of phase with respect to one another, said first phase plate being positioned between said source and said breast, said second phase plate being positioned between said breast and said optical receiver.

29. A transillumination apparatus as recited in claim 28 wherein said first and second phase plates are identical.

30. A transillumination apparatus as recited in claim 28 wherein said first and second phase plates are not identical.

31. A transillumination apparatus for the early detection of breast cancer, comprising:

a source of non-ionizing radiation for producing a collimated beam of radiation of sufficient intensity to pass through a breast;

scanning means for scanning said collimated beam of radiation over said breast;

a phase conjugated mirror for receiving radiation which has passed through the breast, said phase conjugated mirror returning radiation in the same phase as said radiation in said collimated beam; and

an optical receiver for receiving returning radiation from said phase conjugated mirror.

32. A transillumination apparatus for the early detection of breast cancer, comprising:

a source of non-ionizing radiation for producing nonionizing radiation of sufficient intensity to pass through a breast;

an optical receiver for receiving radiation which passes through said breast;

pulsing means for providing pulses of said nonionizing radiation; and

discriminating means for discriminating between radiation which passes straight through said breast and radiation which is scattered within said breast based on the time required for a pulse of said nonionizing radiation to traverse said breast.

33. A transillumination apparatus as recited in claim 32 wherein said optical receiver comprises a photodetector array with a plurality of photodetectors, each of said plurality of photodetectors being selectively activated by said discriminating means to receive radiation at a specific time interval after a pulse of said nonionizing radiation is emitted from said source, said specific time interval corresponding to the time required for said radiation to pass through said breast.

34. A transillumination apparatus as recited in claim 33 wherein said specific time interval is determined relative to standards simulating breast tissue.

35. A transillumination apparatus as recited in claim 32 further comprising first and second phase plates positioned on opposite sides of said breast, each of said phase plates having a plurality of polarized sections where adjacent sections are out of phase with respect to each other.

36. A transillumination apparatus for the early detection of breast cancer, comprising:

a light source producing a collimated beam of non-ionizing radiation of sufficient intensity to pass through a breast;

an optical receiver for receiving radiation which has passed straight through said breast;

first and second light shutters positioned on opposite sides of said breast in the path of said collimated beam; and

a controller for opening and closing said first and second light shutters on a timed basis.

37. A transillumination apparatus as recited in claim 36 wherein said first and second light shutters are electronically actuated by pulses produced by said controller.

38. A transillumination apparatus as recited in claim 36 wherein said optical receiver comprises photographic film which is exposed by light allowed through said second shutter.

39. A transillumination apparatus for the early detection of breast cancer, comprising:

a source of non-ionizing radiation for producing nonionizing radiation of sufficient intensity to pass through a breast;

a photodetector array comprised of a plurality of photodetectors, each of said photodetectors receiving radiation which has passed through said breast, each of said photodetectors producing an electrical signal which corresponds to the intensity of radiation received;

compressing means for compressing said electrical signal to a compressed signal having a frequency range compatible with photographic film; and

exposing means for exposing said photographic film to light having an intensity corresponding to said compressed signal.

40. A transillumination apparatus as recited in claim 39 wherein said exposing means comprises an adapter for receiving said compressed signals and a light emitting diode connected to said adapter, said light emitting diode emitting said light having said intensity corresponding to said compressed signal.

41. A transillumination apparatus for the early detection of breast cancer, comprising:

a source of non-ionizing radiation for producing nonionizing radiation of sufficient intensity to pass through a breast;

photographic film for receiving radiation from said source of nonionizing radiation; and

a semi-permeable mirror positioned between said source of non-ionizing radiation and said breast, said semi-permeable mirror dividing said non-ionizing radiation into a sample beam and a reference beam, said sample beam being directed through said breast before impinging on said photographic film, said reference beam being directed to said photographic film without passing through said breast, whereby a hologram image is created from the interference of said sample beam with said reference beam.

42. A method for providing a collimated beam of light with a very narrow diameter, comprising the steps of:

directing a beam of light through a first plate with a first aperture, said first aperture having a diameter on the order of wavelengths, said first aperture allowing a collimated beam of light having a diameter of said first aperture to pass straight through and refracting the remaining light from said beam of light; and

providing a second plate with a second aperture in the path of said collimated beam of light, said second aperture being slightly larger in diameter than said first aperture, said second plate allowing said collimated beam of light having said diameter equivalent to said first aperture to pass through said second aperture and preventing refracted light from passing therethrough.

43. A method for detecting breast cancer using a transillumination apparatus, comprising the steps of:

scanning a collimated beam of electromagnetic radiation of a first wavelength which is strongly absorbed by fat over a breast;

detecting radiation of said first wavelength which has passed straight through said breast;

preventing scattered light of said first wavelength from being detected;

creating a fat line image from the detected radiation of said first wavelength;

scanning a collimated beam of electromagnetic radiation of a second wavelength which is strongly absorbed by water over said breast;

detecting radiation of said second wavelength which has passed straight through the breast;

preventing scattered light of said second wavelength from being detected;

creating a water line image from the detected radiation of said second wavelength; and

comparing said fat line image and said water line image, tumors being detected by an increased absorption in said water line image with a corresponding decrease in said fat line image.

44. A method as recited in claim 43 further comprising the steps of:

scanning a collimated beam of electromagnetic radiation of a third wavelength which is strongly absorbed by breast tissue over said breast;

detecting radiation of said third wavelength which has passed straight through said breast;

preventing scattered radiation of said third wavelength from being detected;

creating an overall absorption image from the detected radiation of said third wavelength; and

superimposing the fat line image, the water line image and the overall absorption image to create composite image of the breast which shows the relative location of tumors within said breast.

45. A method for creating a composite image of a breast for the early detection of cancer, comprising the steps of:

creating an overall absorption image of the breast by imaging the breast at a first wavelength;

creating a lesion specific image of said breast by imaging the breast at a second wavelength which is specific to a biochemical marker which associates itself with a breast lesion; and

superimposing the lesion specific image on the overall absorption image to create a composite image of the breast.

46. A method for locating a tumor within a breast, comprising the steps of:

imaging said breast at a first angle to create a first image, lesions in said breast appearing on said first image at a first location;

imaging said breast at a second angle to create a second image, lesions in said breast appearing on said second image at a second location; and

determining the three dimensional location of a lesion within the breast from the position of said first location on said first image and the position of the second location on said second image.

47. A method of preventing scattered light from being detected by a photodetector array positioned under a breast when said breast is imaged with a source of non-ionizing radiation, comprising the steps of:

pulsing said source of non-ionizing radiation such that pulses of light impinge on said breast;

selectively activating each of said photodetectors in said photodetector array to receive light which passes straight through said breast at a first programmed time period after a pulse of radiation is emitted from said source, said first programmed time period being equivalent to the time required for a pulse of light to traverse said breast; and

de-activating said each of said photodetectors in said photodetector array such that they cannot receive light at a second programmed time period, said second programmed time period corresponding to a time in which scattered light traverses said breast.

48. A method for the early detection of breast using a transillumination apparatus, comprising the steps of:

opening and closing a first shutter in a path of a collimated beam of non-ionizing radiation emitted from a source of non-ionizing radiation, said non-ionizing radiation being of sufficient intensity to pass through a breast under examination, said first shutter being positioned between said source and said breast;

opening and closing a second shutter in said path of said collimated beam, said second shutter being positioned between said breast and a photodetector array which detects radiation which passes through said second shutter; and

controlling the time of openings and closings of said first and second shutters.

49. A transillumination apparatus for the early detection of breast cancer, comprising:

a source of non-ionizing radiation for producing a collimated beam of nonionizing radiation of sufficient intensity to pass through a breast;

an optical receiver for receiving radiation from said source of nonionizing radiation which passes through said breast;

a modifying means for modifying radiation in said collimated beam to include identifying information, said modifying means modifying said collimated beam before it passes through said breast; and

a discriminating means, positioned between said breast and said optical receiver, for allowing only radiation including said identifying information to impinge on said optical receiver.

50. A method of preventing scattered light produced in a breast that is impinged with a collimated beam of light from being detected by a photodetector array, comprising the steps of:

modifying said collimated beam of radiation to include identifying information before it passes through said breast; and

allowing only radiation including said identifying information to be detected by said photodetector array.