Basic Concepts
What does PET-CT stand for?
Positron Emission Tomography – Computed Tomography
Which PET-CT scan is used to detect rapidly dividing cancer cells?
F18 FDG
What component of PET absorbs gamma rays and emits light?
Scintillation crystals
In which field is PET-CT most commonly used?
Oncology
How many hours should a patient fast before a PET-CT scan?
4–6 hours
What two imaging techniques are combined in PET-CT?
PET and CT
Which tracer is specifically used for prostate cancer detection?
F18 PSMA
What is the function of photomultiplier tubes (PMTs)?
Amplify light signals
What is PET-CT used for in cardiology?
Assess heart function and blood flow
Why must patients avoid strenuous activity before the scan?
To prevent false results from muscle uptake
What type of imaging does PET provide—functional or structural?
Functional
What PET-CT scan detects estrogen receptor-positive breast cancer?
18F-FES
What does the coincidence processing system detect?
True annihilation events (511 keV gamma rays)
What neurological condition can PET-CT help diagnose?
Alzheimer’s disease
What is the purpose of injecting a radiotracer?
To visualize metabolic activity
What is the common radiotracer used in PET-CT scans?
Fluorodeoxyglucose
Which PET-CT scan binds to somatostatin receptors in neuroendocrine tumors?
NetSpot (Gallium Ga 68 Dotatate)
What is the role of the CT gantry?
Produces and rotates X-rays around the patient
How does PET-CT help in infection detection?
Detects hidden infections and inflammation
What should patients do after the scan to eliminate the tracer?
Drink plenty of fluids
Why is PET-CT important in early disease detection?
It detects metabolic changes before structural changes appear
Which type of PET-CT scan requires fasting before the procedure?
F18 FDG
What is image fusion in PET-CT?
Combining PET and CT images into one
What is the purpose of whole-body PET-CT screening?
Detect multiple disease sites
What is one major risk or limitation of PET-CT scans?
Exposure to low-dose radiation