Endoscopic optical assessment of tissue histology
Endoscopy is an extremely important and prevalent procedure for the diagnosis of a variety of disorders affecting the esophageal and gastrointestinal tracts such as colorectal cancer, adenoma, inflammatory bowel disease, and intestinal metaplasia. Endoscopy procedures can be used for image guided surveillance of tissues as well as for the removal of abnormal or diseased structures such as neoplastic, malignant lesions and polyps. State-of-the art optical endoscopes utilize white light for imaging. While this technique provides adequate visualization of tissues layers in direct contact with the probe face, it does not provide any information about underlying tissue structures and is limited in its ability to accurately distinguish the borders between healthy and diseased tissues. Consequently, it leads to high rates of missed abnormalities that may be hidden behind folds in the tissue layers or when lesions are relatively flat.
The proposed device in an endoscopic probe that utilizes a novel optical spectroscopy-based method to reconstruct images with greater functionality and diagnostic accuracy. Using this technique could raise detection rates of diseased tissues, decrease procedure times for surveillance procedures, and improve accuracy of targeted tissue biopsies. The device uses optimized photodetector-based apertures for the detection and interrogation of tissue using diffuse reflectance spectroscopy of optical signals. In addition, the highly customizable photodetectors can be used for spatially-resolved imaging thereby providing information about the tissue through depth so as to circumvent tissue folds.
While these technologies have been proposed for implementation on colonoscopes, they can also be extended to other forms of endoscopes as well as instruments used for laparoscopic surgery.
The use of photodetectors for imaging (over optical fibers) is not only more efficient but also allows for optimization of the optical properties that the device is sensitive to based on the tissue to be imaged. It would improve the accuracy of colonoscopies, decrease the need for follow-up scans and could even reduce the number of physical biopsies – thereby reducing the risk for patients. Additionally, the proposed device provides the potential for customization on not only the photo-detectors but also the light source. These could both be optimized to improve targeting of specific tissues based on their optical properties as well as physical location i.e. depth and orientation.