Improving spatial resolution of a fiber bundle optical biopsy system

To reduce the number of invasive tissue biopsies and needle aspirations performed during cancer screenings, endo-microscopes can be used to image tissue in vivo. However, when optical fiber bundles are used to transmit the image, the resolution of such systems is limited by undersampling due to the spacing of the bundle's individual fibers for a given field of view. We propose a method to increase the sampling of an optical biopsy system and thereby improve the system's resolution. The method involves taking several images, shifting the object and fiber bundle slightly relative to each other from one image to the next. Multiple shifting patterns were evaluated to determine which provided the greatest increase in resolution. The shifted images are later realigned and recombined by a custom algorithm. By combining four shifted images of a USAF resolution target, we were able to measure an improvement in the resolution of the system from approximately 3.9 mu m to 2.2 mu m. When tested on cultured cells, a visible increase in detail was detectable. This technique can provide the basis for improving the diagnostic abilities of optical biopsy systems.