FREE ABR Nuclear Medical Physics Questions and Answers
What is the primary difference between positron emission tomography (PET) and single-photon emission computed tomography (SPECT)?
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.
Which of the following isotopes is commonly used in PET imaging for detecting cancer?
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.
What does the half-life of a radioisotope affect in nuclear medicine?
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.
What is the primary function of a gamma camera in nuclear medicine?
A gamma camera detects gamma rays emitted by radiopharmaceuticals injected into the patient. It is commonly used in SPECT imaging to produce diagnostic images.
In nuclear medicine, what does the term "uptake" refer to?
"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.