Positron Emission Tomography (PET) is a type of medical imaging called molecular imaging. It uses very small amounts of radioactive materials called radiopharmaceuticals, or tracers, to provide detailed pictures of what is happening inside the body at the molecular and cellular level. PET imaging aids in the diagnosis and treatment of disease, particularly for various types of cancers, cardiovascular disease and neurological disorders.
Other diagnostic imaging procedures-such as x-rays, computed tomography (CT) and ultrasound-offer pictures of physical structure, while molecular imaging allows physicians to see how the body is functioning and to measure its chemical and biological processes.
Molecular imaging offers unique insights into the human body that enable physicians to personalize patient care. In terms of diagnosis, molecular imaging is able to:
- Provide information that is unattainable with other imaging technologies or that would require more invasive procedures such as biopsy or surgery
- Identify disease in its earliest stages and determine the exact location of a tumor, often before symptoms occur or abnormalities can be detected with other diagnostic tests
There are several tracers used in PET imaging today:
- FDG (fluorodeoxyglucose): used to measure metabolism and evaluate metastatic disease in soft tissue
- NaF (sodium fluoride): used to visualize molecular activity in skeletal bones and to evaluate metastatic disease in bony anatomy/bones
- Choline C-11: used to visualize cell proliferation, or production, and evaluate cancer recurrence
- Florbetapir F-18, Flutemetamol F-18 and Florbetaben F-18: used to estimate β-amyloid plaque density in adult patients with cognitive impairment who are being evaluated for Alzheimer’s Disease and other causes of cognitive decline
- Fluciclovine F-18: used to detect suspected recurrent prostate cancer in men with elevated prostate specific antigen levels following prior treatment
- Gallium Ga 68 Dotatate: used to detect somatostatin receptor positive neuroendocrine tumors
- Nitrogen N-13 Ammonia: used to evaluate myocardial perfusion in patients with existing or suspected coronary artery disease
- Rubidium Rb 82: used to evaluate regional myocardial perfusion in adult patients with suspected or existing coronary artery disease
(Source: Society of Nuclear Medicine and Molecular Imaging, FDA website, product labels)
