Nuclear medicine II Flashcards
Primary interaction NaI in Tc99 imaging
Photoelectric (High Z material)
Energy resolution for Tc 99 m on Gamma camera
10 % (14%, because the FHWM)
Energy resolution
Photopeak broadening as a percentage of photopeak energy
If energy resolution is 10% (10% FWHM) what is the energy window
20%
What is the sensitivity range of well counter (contamination testing)
nCi
Pulse height analyzer window width
20%
What detectors DOES have gas and DOES NOT have NaI
Dose calibrators (before injection measure). - Provide radioisotope info
What is ACLG used for QA
ACLG is used for dose calibrators
- A: Accuracy annual
- C: Constancy daily
- L: Linearity quaterly
- G: Geometry Installation
Dose calibrators have a high accuracy (injection within 20%)
Medium energy collimators
Ga 67
K 81
In 111
High energy collimators
I-131
Accuracy required for dose injected (NRC comission)
20%
Low energy collimator
Tc99 m and I123
Intrinsic
withou collimator (INdependent)
extrinsic
with collimator (EXtra)
What is this artifact?
Craked crystasl
What is this
Photomultiplier not working
What is this artifact
Ununiformity (captured using flood field)
Poor uniformity calibration
Whatis this
Septal penetration
How to decrease resolution of nM
Increase parallel hole colimator - patient distance
Mottle of 100 counts/pixel in uniformioty flood?
10% (Mottle=1/square root of dose to receptor)
Extrinsic system resolution of NM gamma camera
8 mm
What is
Change energy window
Pinhole
Thyroid
