A new 3-D colonoscopy technique may help doctors detect more pre-cancerous lesions by using an add-on that can be easily incorporated into existing endoscopes. The technology, photometric stereo endoscopy, is in development at MIT.
Conventional colonoscopy misses an estimated one out of every four lesions, according to the researchers' study, published in the Journal of Biomedical Optics. While endoscopy uses tissue color contrast to detect lesions, for some lesions, their topographical contrast says more about them than their color.
The new technology captures both color and topographical measurements for more accurate detection of smaller lesions.
"In conventional colonoscopy screening, you look for these characteristic large polyps that grow into the lumen of the colon, which are relatively easy to see," said researcher Nicholas Durr in a release. "However, a lot of studies in the last few years have shown that more subtle, nonpolypoid lesions can also cause cancer."
CT colonoscopy, or CTC, only shows tomography, but is rarely used because it can lead to pricey follow-up screenings.
The PSE researchers say their technology will be an inexpensive way to bring in tomographical images, as it can be added on to existing endoscopes.
Most endoscopes use multiple light sources simultaneously to reduce shadowing and increase color contrast. To add on PSE, modification would only need to be made to light source cycling, to acquire images using different illumination conditions, and to camera frame synchronization.
The researchers now plan to test the technology in clinical trials.