Advances in 3D-imaging technology using optic fibres could pave the way for pain-free, real-time medical biopsy results.
Existing optical fibre technology could help doctors bypass wait times for biopsy results.
Currently, biopsies require tissue samples harvested from patients to be sent off to a lab for analysis. But researchers from RMIT University, Macquarie University and Swinburne University found that optical fibre technology could be used to produce 3D images of tissue instead.
This approach would mean doctors could examine living tissue in real time, while patients can avoid invasive surgery and long wait times.
In stereo
The research, led by RMIT’s Dr Antony Orth and published in Science Advances, looked at ways to repurpose ultra-thin microendoscopes. The technology has been used to peer inside the body during surgery or for diagnosis, but so far its potential to produce 3D images has remained untapped.
Optical fibre bundles transmit information in the form of a light field, but the challenge was to unscramble this information into a 3D image. Their technique draws on principles of light field imaging, whereby multiple cameras capture the same image from different angles to create a multi-viewpoint image.
It’s similar to stereo vision, which might be familiar if you have ever watched a 3D movie while wearing 3D glasses.
“Stereo vision is the natural format for human vision, where we look at an object from two different viewpoints and process these in our brains to perceive depth,” said Orth, who along with his research partners is part of the ARC Centre of Excellence for Nanoscale Biophotonics (CNBP).
“We’ve shown it’s possible to do something similar with the thousands of tiny optical fibres in a microendoscope.”
According to Orth, optical fibres can capture images from multiple perspectives, providing depth perception in the form of a light field.
“Our approach can process all those microscopic images and combine the viewpoints to deliver a depth-rendered visualisation of the tissue being examined — an image in three dimensions,” Orth said.
Light goes in, light goes out
Accurately recording these observations was another challenge. Orth said the pattern produced at one end of the fibre depends on the angle at which light entered the other end. The research team developed a mathematical framework to relate the output patterns to the angle of the light rays.
“By measuring the angle of the rays coming into the system, we can figure out the 3D structure of a microscopic fluorescent sample using just the information in a single image,” said Professor Brant Gibson, Chief Investigator and Deputy Director of the CNBP.
“That optical fibre acts like a miniature version of a light field camera.”
The technique worked even when the fibres bent or flexed — essential traits for use in the human body. Gibson added that the technique is compatible with existing optical fibre technology, meaning “3D optical biopsies could be a reality sooner rather than later”.
