Positron Emission Tomography Imaging of the Human Brain Using a Radiotracer

Positron emission tomography, or PET, can measure glucose metabolism, which reflects neuronal activity within the brain.

To begin, position the participant on the scanner bed with a pre-inserted cannula.

Connect and secure the infusion tubing to deliver the tracer solution at a controlled rate throughout the scan.

Conduct a localizer scan to confirm the accurate positioning and verify PET parameters.

Initiate the PET acquisition, then begin the infusion of the tracer, 18-fluorine fluorodeoxyglucose (FDG), a glucose analog labeled with radioactive fluorine.

Within an active neuron, FDG is metabolized to FDG-6-phosphate and accumulates inside.

The radioactive fluorine undergoes decay, emitting a positron that interacts with a nearby electron, producing photon pairs traveling in opposite directions.

The PET detector records these emitted photons during the scan and generates a high-resolution image showing tracer distribution within the brain.

Position the participant in the scanner and cover with a disposable blanket to maintain a comfortable body temperature. Flush the cannula to ensure it is patent with minimal resistance before connecting the infusion line. Tape the tubing to the participant's wrist and instruct them to keep their arms straight during the scan.

Situate the NMT in the scanner room to monitor the infusion equipment. Ensure the NMT wears hearing protection and uses the barrier shield to minimize radiation exposure from the dose where possible. Perform the localizer scan to ensure that the participant is in the correct position and check the details for the PET acquisition.

Then signal the NMT to start the infusion pump 30 seconds after the start of the PET acquisition. Have the NMT observe the pump to ensure it has started to infuse the FDG and ensure there is no immediate occlusion of the line.