New optical brain scanner can see your brain ‘blush’, rivals PET & MRI without using radiation or super-magnets

 Breakthroughs in scanning technology are often couched in terms of their potential for real-world impacts; a better PET scanner or MRI machine is certainly nice, but ultimately limited by the dangers of radiation exposure or the costs of superconducting magnet rigs. So, doctors and researchers have longed for a way to collect some information cheaply and without adding any extra risks to the patient. Optical scanners — as in, plain old safe infrared light — have been making progress toward this goal for some time, but this week Nature published findings that imply the technology could finally be ready for the big time.

When an area of the brain starts working, its use of oxygen spikes dramatically. In a functional (real-time) MRI scan, the magnetic differences between oxygen-rich and oxygen-deprived blood let operators see where and when neurons are firing, but the super-powerful magnets needed for this technique mean the machines are far too big and expensive for truly widespread use.
On the other hand, DOT scans detect oxygenation by watching for changes in colour and intensity of low intensity light beams shone straight into your noggin. Senior author of the study Joseph Culver compared the process to seeing embarrassment in a rush of blood to the cheeks — though in this case, the “cheeks” are the brain lobes inside your skull, and the “embarrassment” could be anything from outright lust to complex logical thought.
Penetrating your head with light might sound dangerous, but the non-ionizing radiation used by a DOT machine is theoretically incapable of causing damage — which is more than you can say for PET scanning. PET scans involve injecting a patient with radioactive isotopes that we can watch move through the body; it’s a calculated risk, and often avoided because the potential to harm outweighs the potential to help.

 If the researchers can prove that there is a viable biomedical market for their invention, however, expect these performance numbers to spike dramatically. Right now this is being suggested for use in children or those with implants — people who cannot take conventional scans as easily as most of us. Still, with all the potential advantages in cost and safety, the team’s long-term goals should be much, much loftier than that.