A miniaturized PET brain scanner has been developed by the team of researchers at West Virginia University and the University of Virginia. The scanner can be 'worn' like a helmet, allowing research subjects to stand and make movements as the device scans. This Ambulatory Microdose Positron Emission Tomography (AMPET) scanner could launch new psychological and clinical studies on how the brain functions when affected by diseases from epilepsy to addiction and during ordinary and dysfunctional social interactions. Scientists could use AMPET to study Alzheimer’s (lat. morbus Alzheimerianus) or traumatic brain injuries, or even our sense of balance.
In designing the small-scale scanner, the team used recent advances in detector technology. For instance, they used dense crystals to convert the gamma photons generated by positron-electron interactions into visible light, along with small light-detecting sensors called avalanche photodiodes. They also used special electronics developed at Brookhaven and built into the compact, lightweight PET detector. Suspending the structure on long springs helped support its weight so rats could 'wear' the scanner while moving around easily.
The AMPET team hopes to start developing a full-brain scanner soon - one that covers the entire head rather than examining a horizontal five-centimeter section, like the current ring. Because AMPET sits so close to the brain, it can 'catch' more of the photons stemming from the radiotracers used in PET than larger scanners can. That means researchers can administer a lower dose of radioactive material and still get a good biological snapshot. Catching more signals also allows AMPET to create higher resolution images than regular PET.
But most importantly, PET scans allow researchers to see further into the body than other imaging tools. This lets AMPET reach deep neural structures while the research subjects are upright and moving. From a psychologist’s or neuroscientist’s perspective, AMPET could open doors to a variety of experiments, from exploring the brain’s reactions to different environments to the mechanisms involved in arguing or being in love.
In the medical sphere, the scanning helmet could help explain what happens during drug treatments or shed light on movement disorders. The researchers have successfully imaged the brain of someone walking in place. Now they are ready to build a laboratory-ready version.