Instruments and methods for imaging collagen structure in vivo
Instruments and methods for wide-field polarized imaging of the skin to determine an outer lesion margin objectively in vivo to provide guidance to a surgeon. Quantitative characterization of collagen structures in the skin can be used to determine the outer lesion margin or monitor skin treatment.
1. An instrument for imaging a region of tissue to optimize in vivo determination of a boundary of a tumor, the instrument comprising:
an illuminator configured for illuminating the region with at least one wavelength of light;
an imaging detector configured for generating images of the region based upon cross-polarized light reflected from the region, wherein the at least one wavelength determines a depth of the images in the tissue; and
a computer connected to the imaging detector and configured for receiving and storing the images, wherein the depth of the images in the tissue is selected to illustrate a collagen structure of the tissue so that the images are presented to a surgeon for determining surgical margins around the tumor based upon disruption in the collagen structure, wherein the computer is operative to:
form a number of sub-areas of the images;
classify each sub-area as one of: lesion; normal; and borderline based upon a reflectance of the sub-area, wherein: sub-areas classified as borderline have a reflectance within a range; sub-areas classified as normal have a reflectance above the range; and sub-areas classified as lesion have a reflectance below the range; and
form an outer margin from stitching together consecutive borderline sub-areas.
2. The instrument of claim 1 , wherein the at least one wavelength is adjusted to match a depth of the collagen structure according to a location of the region on a patient.
3. The instrument of claim 1 , wherein the at least one wavelength is in a range of 380 nm to 550 nm.
4. The instrument of claim 1 , further comprising a treatment device coupled to the computer for removing a portion of the region according to the surgical margins.
5. The instrument of claim 1 , wherein presence of basal cell carcinoma causes the disruption of the collagen structure which results in a localized darkening in the images.
6. The instrument of claim 1 , wherein the images are taken in vivo with an initial surgeon's marker drawn on the tissue.
7. The instrument of claim 1 , wherein the light is monochromatic blue light.
8. The instrument of claim 1 , wherein the boundary delineating the tumor based on analysis of the images is superimposed upon at least one of the images.
9. The instrument of claim 1 , wherein the computer determines the surgical margins by:
comparing a reflectance value of each of the images to a normal reflectance value, wherein: when the reflectance value of the images is below the normal reflectance value by a predetermined amount, an area associated with the respective image is identified as an unhealthy area; and when the reflectance value of the images is within the predetermined amount of the normal reflectance value, an area associated with the respective image is identified as a healthy area; and
forming the surgical margins based upon transitions from the unhealthy areas to the healthy areas.
10. The instrument of claim 9 , wherein the reflectance value is based upon factors selected from the group consisting of: an age of a patient on which the region is located; a location of the region; quantified parameters of pixel intensity distribution; collagen-occupied area defined as a percentage of pixels above a certain threshold brightness; and a quantitative measure of a degree of order in the image, such as approximate entropy or Tsallis entropy; and combinations thereof.
11. The instrument of claim 1 , wherein the computer is operative to: collect normal images from a healthy region of tissue; and determine a normal reflectance value based upon the normal images.
12. The instrument of claim 1 , wherein the computer is operative to apply thresholding to the images for increased contrast.
13. An instrument for imaging a region of tissue to evaluate collagen structure, the instrument comprising:
an illumination ring configured for illuminating the region with at least one wavelength of light;
an imaging detector configured for generating images of the region based upon cross-polarized light reflected from the region over a period of time; and
a computer connected to the imaging detector and configured for receiving and storing the images, wherein the images are of a depth in the tissue that illustrates the collagen structure so that the images are compared over the period of time to evaluate a treatment of the region, wherein the computer is operative to:
form a number of sub-areas of the images;
classify each sub-area as one of: lesion; normal; and borderline based upon a reflectance of the sub-area, wherein: sub-areas classified as borderline have a reflectance within a range; sub-areas classified as normal have a reflectance above the range; and sub-areas classified as lesion have a reflectance below the range; and
form an outer margin from stitching together consecutive borderline sub-areas.
14. A method of imaging a region of tissue to optimize in vivo determination of a boundary of a tumor, the method comprising:
illuminating the region with at least one wavelength of light;
generating images of the region based upon cross-polarized light reflected from the region, wherein the at least one wavelength determines a depth of the images in the tissue; and
receiving and storing the generated images, wherein the depth of the images in the tissue is selected to illustrate a collagen structure of the tissue;
determining a surgical margin around the tumor based upon disruption in the collagen structure, wherein determining the surgical margin includes:
forming a number of sub-areas of the images;
classifying each sub-area as one of: lesion; normal; and borderline based upon a reflectance of the sub-area, wherein: sub-areas classified as borderline have a reflectance within a range; sub-areas classified as normal have a reflectance above the range; and sub-areas classified as lesion have a reflectance below the range; and
forming an outer margin from stitching together consecutive borderline sub-areas.
15. The method of claim 14 , further comprising adjusting the at least one wavelength to match a depth of the collagen structure according to a location of the region on a patient.
16. The method of claim 14 , wherein the at least one wavelength is in a range of 380 nm to 550 nm.
17. The method of claim 14 , further comprising removing a portion of the region according to the surgical margin.
18. The method of claim 14 , wherein presence of basal cell carcinoma causes the disruption of the collagen structure which results in a localized darkening in the images.
19. The method of claim 14 , wherein the images are taken in vivo with an initial surgeon's marker drawn on the tissue.
20. The method of claim 14 , wherein the light is monochromatic blue light.
21. The method of claim 14 , further comprising superimposing the boundary delineating the tumor based on analysis of the images upon at least one of the images.
22. The method of claim 14 , wherein determining the surgical margin includes:
comparing a reflectance value of each of the images to a normal reflectance value, wherein: when the reflectance value of the images is below the normal reflectance value by a predetermined amount, an area associated with the respective image is identified as an unhealthy area; and when the reflectance value of the images is within the predetermined amount of the normal reflectance value, an area associated with the respective image is identified as a healthy area; and
forming the surgical margins based upon transitions from the unhealthy areas to the healthy areas.
23. The method of claim 22 , wherein the reflectance value is based upon factors selected from the group consisting of: an age of a patient on which the region is located; a location of the region; quantified parameters of pixel intensity distribution; collagen-occupied area defined as a percentage of pixels above a certain threshold brightness; and a quantitative measure of a degree of order in the image, such as approximate entropy or Tsallis entropy; and combinations thereof.
24. The method of claim 14 , further comprising:
collecting normal images from a healthy region of tissue; and
determining a normal reflectance value based upon the normal images.
25. The method of claim 14 , further comprising applying thresholding to the images for increased contrast.