Week 2 Part 2 Flashcards
(59 cards)
Nuclear Medicine imaging technology developed for __
diagnosis of human disease and study of human physiology
PET is more sensitive in early diagnosis of __
neurology, oncology, cardiology
PET imaging is very useful in ___
- measuring blood flow into tissues / tumours
- imaging and measuring receptors
- imaging enzyme & cellular functions
isotopes of naturally occurring elements are excellent tracers such as ___
carbon, oxygen, fluorine
F-18 half-life
110 mins
C-11 half-life
20 mins
N-13 half-life
10 mins
Oxygen-15
2 mins
Rubidium-82 half-life
76 secs
PET relies on ___
radioisotope decay via positron emissions
protons decays to __
neutron, positron, neutrino
as positrons travel through human tissue, they give up KE via ___
Coulomb interactions with electrons
positrons annihilate with nearby electrons, resulting in ___
2 gamma rays of 511KeV traveling at 180 degrees to each other.
when can positron-electron annihilation can be calculated and determined
when both gamma rays are detected
coincidence events can be stored in arrays corresponding to ___
projections through the patient and reconstructed using standard tomographic techniques
coincidence events in PET are divided into 3 categories which are ___
true, scattered, random
true coincidences occur when ___
both photons from annihilation event are detected in coincidence
which 3 invalid events causes statistical noise to data
scatter, random, attenuation
block of PET detector crystals are made of __
LSO/LySO
Transmission map provides ___ by CT
physical scatter boundaries
Emission map provides ____ by PET
distribution of activity, including scatter
scatter maps are used to correct __
PET scans
problem of attenuation
photons stopped in patient’s body before reaching PET detectors
problem of consequences
reduces appearances of deep lesions and quantitative accuracy
