PET

Question 1

How would you explain PET to a non-scientist?

Answer 1

• Nucleotide injected into patient collects at areas of high metabolic activity (eg. tumour)
• Nucleotide decays by beta+ decay, positron is released
• Positron travels short distance before annihilation with an electron producing two (almost) antiparallel 511 keV photons
• PET camera detects these photons at near simultaneous times - we know annihilation must have happened along that line.
• Adding up all the photons along all the lines and deconvoluting gives actual image

Question 2

What are the advantages of PET?

Answer 2

• No collimation needed for PET –> greater resolution