Flashcards in Other random questions Deck (5):
1
What is involved in a PET scan?
Injection of a glucose analogue (18F-FDG) which is taken up by cells with glucose transporter proteins.
Glucose is then phosphorylated by hexokinase to FDG-6 phosphate and FDG-phosphate is trapped in the cells.
Malignant cells have a high metabolic rate and high level of uptake of glucose
2
What can give a false negative on a PET scan?
Raised serum glucose as less FDG will be taken up by tumour cells as normal glucose is competing for receptors - patients are usually fasted before a scan to prevent this
3
What are sites on a PET that physiologically take up FDG?
Brain
Urinary system
Liver and spleen
4
What can give a false positive on a PET?
Brown fat
Infections (Tb)
Sarcoidosis
Recent surgery
5