A PET/CT scan or Positron Emission Tomography, is a fusion of functional imaging (from the PET component) combined with anatomical imaging (from the CT component).
In PET imaging a small amount of radioactive material (tracer) is injected into the patient. The tracer disperses throughout the bloodstream and gives off energy in the form of gamma rays.
These gamma rays are then detected by the scanner, which allows for very detailed images of the body to be generated, together with information about how tissues and organs are functioning.
PET scans provide quantitative information at a cellular level and as such are beneficial in a range of oncologic instances – including the assessment of cancer, how it metabolises, whether it has spread in the body and how a tumour might be responding to treatment.