OPT also fills in the imaging gap: traditionally, specimens between 1 and 10 millimeters were too big to image with a confocal microscope and too small to put in an MRI scanner. OPT is also less costly and can sometimes offer higher-resolution images than an MRI scanner.
“While you can put a human in an MRI scanner, you just don’t have that option with something much smaller,” says McGurk.
There are, of course, limitations to the use of OPT because the resolution is dependent on the transparency of the sample. Some brain-imaging experts say that although this technology may help scientists understand the mechanisms of neurodegeneration, it won’t be used in adult human brains anytime soon.
“There is very little clinical application to this, since the light would have to go through the head,” says Michael Weiner, who works in MRI imaging of Alzheimer’s and other diseases at the University of California San Francisco Medical Center. “I think that it is a technique which needs to be further developed [before it can be used] for human applications.”
Sharpe says that the team is already working on ways to improve the resolution and contrast.