ABSTRACT
Maxillofacial imaging has evolved in parallel with the development of newer imaging technologies. Traditional plain radiography and dental imaging are frequently supplemented by cross-sectional modalities such as computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound, together with functional imaging modalities such as positron emission tomography (PET). A CT scanner consists of an x-ray tube which sends a fan of x-rays through the patient and the attenuation of the beam by the patient is detected. The process is repeated as the tube and detectors rotate and the patient is advanced through the scanner. Most PET imaging studies of the head and neck use the short-lived radiotracer 18-fluorodeoxyglucose (18FDG), which allows an examination of altered glucose metabolism as a marker of tumour activity. The unstable radioisotope releases a positron over a short distance after which it annihilates with an electron and emits the photons that are detected.
