PET imaging uses positrons emitted by a radiopharmaceutical, which combine with electrons in the body to produce gamma rays. SPECT uses single photon-emitting radioisotopes to capture images, involving different mechanisms.
Fluorine-18 is commonly used in PET imaging, especially for detecting cancers, as it is incorporated into glucose molecules, allowing for the visualization of high metabolic activity typical of tumors.
The half-life of a radioisotope determines how long it takes for half of the substance to decay, which in turn affects how long the patient is exposed to radiation. Shorter half-lives reduce the radiation burden on the patient.
A gamma camera detects gamma rays emitted by radiopharmaceuticals injected into the patient. It is commonly used in SPECT imaging to produce diagnostic images.
"Uptake" refers to how well the target tissue absorbs the radioactive isotope, which is essential for imaging and diagnosis, especially in identifying cancerous or abnormal tissue.