Researchers at the University of Exeter in England have developed a technique to image tissues through an ultrathin optical fiber, potentially allowing for high-resolution imaging of single cells within the body. The optical fibers are as thin as a human hair, and could lead to tiny endoscopes that can be inserted into human tissues to image individual cells. If developed further, the technique could help clinicians identify diseased cells within the body, and help with the accurate placement of needles to obtain biopsy samples.
Endoscopy is an invaluable technique that allows clinicians to peer inside our bodies while causing minimal damage. However, conventional endoscopes are limited to inspecting tissues at a gross level, and individual cells remain a mystery unless removed from the body and analyzed using benchtop microscopes. Single-cell imaging in vivo remains out of reach for conventional endoscopy, but this latest technology may be about to change that.
The new technique employs tiny optical fibers, the size of a human hair. However, imaging using such fibers requires some finesse, since the fiber significantly scrambles the light that travels along it, rendering any images blurry and useless. Thankfully, it is possible to unscramble the signal to form a legible image by first understanding how the fiber distorts the light and then working backwards to identify specific calibration information that can decipher the image. The researchers refer to this calibration information as a ‘key’, and recently developed a way to calculate it very quickly.
However, the image distortion also changes depending on how the flexible fiber is bent or twisted, meaning that insertion into the body would be unlikely to render a decent image since the fiber is bound to flex during this process. To address this, the researchers used a method to dynamically track image distortion and adjust the key accordingly during imaging.
Interestingly, this corrective technique was borrowed from astronomy, where it is used to view the night sky through atmospheric turbulence. It involves using a ‘guide star’ – in this case a fluorescent particle at the fiber tip – which the researchers use as a frame of reference to calculate image distortion and correction. The technique could lead to high-resolution endoscopes that can image individual cells to identify disease.
“We hope that our work brings the visualization of sub-cellular processes deep inside the body a step closer to reality – and helps to translate this technology from the lab to the clinic,” said David Phillips, a researcher involved in the study, in a University of Exeter announcement.
Study in Nature Communications: Memory effect assisted imaging through multimode optical fibres
Via: University of Exeter