Fluorescence, reflectance and light scattering spectroscopy for measuring tissue

• US 20020143243A1
• Filed: 01/19/2001
• Published: 10/03/2002
• Est. Priority Date: 01/19/2001
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Georgakoudi, Irene, Backman, Vadim, Feld, Michael S.
• Granted Patent: US 6,697,652 B2
• Time in Patent Office: Days
• US Class Current: 600/310
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• CPC Class Codes: A61B 5/0075 by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy A61B5/0071 takes precedence
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/4331 of the cervix A61B5/435 takes precedence
• CPC Class Codes: G01N 21/47 Scattering, i.e. diffuse reflection G01N21/25, G01N21/41 take precedence G01N21/55 takes precedence
• CPC Class Codes: G01N 21/64 Fluorescence; Phosphorescence
• CPC Class Codes: G01N 21/6486 Measuring fluorescence of biological material, e.g. DNA, RNA, cells G01N21/6428 takes precedence

Abstract

The present invention utilizes a plurality of spectroscopic techniques to measure characteristics of tissue useful in the diagnosis of disease. Fluorescence, reflectance and light scattered spectra can be measured and processed to determine the size, distribution and/or composition of tissue. The methods and systems can be used particularly in the early detection of carcinoma within tissue in vivo and in vitro.

Claims

1. A method of measuring a structure in a layer of tissue comprising:

directing incident radiation from a broadband light source onto a region of interest in the layer of tissue;

collecting fluorescent and reflected radiation from the tissue at a plurality of wavelengths;

detecting the collected radiation to provide a fluorescence spectrum, a reflectance spectrum and a scattered spectrum as a function of wavelength; and

determining a plurality of characteristics including a size of a structure within the tissue layer with the measured spectra.

2. The method of claim 1 further comprising determining if the region of interest includes dysplastic tissue.

3. The method of claim 1 further comprising directing radiation onto the tissue using a fiber optic probe.

4. The method of claim 1 further comprising collecting the radiation from the tissue with a fiber optic probe.

5. The method of claim 1 further comprising determining an average nuclear size of nuclei within the region of interest.

6. The method of claim 1 further comprising measuring a diameter of a tissue nucleus within the region of interest.

7. The method of claim 1 further comprising measuring a periodic component of an intensity of radiation from the tissue as a function of wavelength.

8. The method of claim 7 further comprising determining the size of a nucleus in the tissue from the periodic component.

9. A method of optically measuring tissue comprising:

directing incident radiation onto a region of interest in tissue to be measured;

collecting fluorescent and diffusely reflected radiation from the tissue; and

measuring a periodic component of collected radiation as a function of wavelength to determine a physical characteristic of the tissue.

10. The method of claim 9 further comprising determining if the region of interest includes dysplastic tissue.

11. The method of claim 9 further comprising directing radiation onto the tissue using a fiber optic probe.

12. The method of claim 9 further comprising collecting the radiation from the tissue with a fiber optic probe.

13. The method of claim 9 further comprising determining an average nuclear size of nuclei within the region of interest.

14. The method of claim 9 further comprising measuring a diameter of a tissue nucleus within the region of interest.

15. The method of claim 9 further comprising collecting radiation with an endoscope, the endoscope having an imaging sensor at a distal end of the endoscope.

16. The method of claim 9 further comprising determining a density of nuclei in the tissue from the periodic component.

18. The method of claim 17 further comprising determining if the region of interest includes dysplastic tissue.

19. The method of claim 17 further comprising collecting radiation in the range of 350 nm to 700 nm.

20. The method of claim 17 further comprising collecting the radiation from the tissue with a fiber optic probe.

21. The method of claim 17 further comprising determining an average nuclear size of nuclei within the region of interest.

22. The method of claim 17 further comprising measuring a diameter of a tissue nucleus within the region of interest.

23. The method of claim 17 further comprising measuring a periodic component of an intensity of scattered radiation from the tissue as a function of wavelength.

24. The method of claim 17 further comprising determining the size of a nucleus in the tissue from the periodic component.

26. The method of claim 25 further comprising directing radiation onto the material using a fiber optic probe.

27. The method of claim 25 further comprising collecting the radiation from the material with a fiber optic probe, the probe having an optical fiber with a numerical aperture in a range of 0.05-0.25.

28. The method of claim 25 further comprising determining an average nuclear size of nuclei within the region of interest.

29. The method of claim 25 further comprising measuring a number of particles per unit area within the region of interest.

17. A method of determining a presence of dysplasia in tissue comprising:

directing incident radiation onto a region of interest in an epithelial layer of tissue;

collecting backscattered radiation from the tissue;

detecting the collected backscattered radiation with a detector;

determining a size of a structure within the epithelial layer of tissue using the detected radiation; and

determining the presence of dysplasia in the region of interest of the tissue.

25. A method of optically measuring a material comprising:

directing incident radiation onto a region of interest in the material tissue to be measured;

collecting fluorescent and reflected radiation from the material;

detecting a fluorescence spectrum and a reflectance spectrum from the collected radiation; and

measuring a periodic component of the detected reflectance spectrum as a function of wavelength to determine a plurality of physical characteristics of the material from the fluorescence spectrum and the reflectance spectrum.

30. An apparatus for optically measuring tissue comprising:

a first radiation source and a second radiation source that illuminate a region of interest in tissue to be measured with incident radiation;

an optical system that collects fluorescence and reflected radiation from the tissue;

a detector system that senses the collected fluorescence and reflected radiation; and

a data processor that determines a periodic component of detected radiation as a function of wavelength to determine a physical characteristic of the tissue.

31. The apparatus of claim 30 further comprising a filter wheel and a broadband light source that generates light in a range of 350-700 nm.

32. The apparatus of claim 30 further comprising a fiber optic probe that couples the first radiation source and the second radiation source to a single region of interest on the tissue.

33. The apparatus of claim 30 wherein the data processor generates a scattering spectrum from the detected reflected radiation and generates a modulated fluorescence spectrum with collected fluorescence and reflected radiation.

34. The apparatus of claim 33 wherein the probe is insertable in an endoscope.

36. The method of claim 35 further comprising determining if the region of interest includes dysplastic tissue.

37. The method of claim 35 further comprising directing radiation onto the tissue using a fiber optic probe.

38. The method of claim 35 further comprising collecting the radiation from the tissue with a fiber optic probe.

39. The method of claim 35 further comprising measuring a diameter of a tissue nucleus within the region of interest.

40. The method of claim 35 further comprising measuring a periodic component of an intensity of radiation from the tissue as a function of wavelength.

41. The method of claim 40 further comprising determining the size of a nucleus in the tissue from the periodic component.

35. A method of measuring a size and composition of a structure in a layer of tissue comprising:

directing incident radiation onto a region of interest in the layer of tissue;

collecting fluorescence and reflected radiation from the tissue;

detecting the collected fluorescence and reflected radiation; and

identifying and determining an average nuclear size of nuclei within the region of interest using the detected radiation.

42. A method of measuring a structure in a layer of tissue comprising:

directing incident radiation onto a region of interest in the layer of tissue;

collecting fluorescent and reflected radiation from the tissue;

detecting the collected radiation;

measuring a size of a tissue component in the region of interest with the detected scattered radiation; and

processing a fluorescence spectrum with a reflectance spectrum to provide a modified fluorescence spectrum.

43. The method of claim 42 further comprising determining if the region of interest includes dysplastic tissue.

44. The method of claim 42 further comprising directing radiation onto the tissue using a fiber optic probe.

45. The method of claim 42 further comprising collecting the radiation from the tissue with a fiber optic probe.

46. The method of claim 42 further comprising determining an average nuclear size of nuclei within the region of interest.

47. The method of claim 42 further comprising measuring a periodic component of an intensity of radiation from the tissue as a function of wavelength.

48. The method of claim 47 further comprising determining the size of a nucleus in the tissue from the periodic component.