May 18, 2015
Simulations performed in Germany suggest that a detector sensitive to Cerenkov radiation could one day improve PET contrast and resolution. The detector, which would surround a Cerenkov radiator on six sides, would be able to reveal the "time-of-flight" of generated gamma rays, as well as their point of interaction on the detector (Med. Phys. 42 1825).
PET is an imaging technique that allows a specialist in nuclear medicine to monitor processes inside the body by injecting a radioactive, positron-emitting tracer. Each positron emitted by the tracer shortly annihilates with electrons in the tissue to produce a pair of gamma rays, which are captured in a detector. In a typical PET detector, these gamma rays interact with crystals to produce scintillation light, which is recorded by a photodetector. By mapping the location of lots of bursts of scintillation light, it is then possible to work out where the original gamma-ray pair was generated – and hence the position of the tracer.