MRI Safety Flashcards
What is the potential for permanent, irreversible injury to the patient?
safety hazard
What’s the potential for a temporary, reversible effect on the patient?
biologic response
What is the safety line drawn around the perimeter of the main magnet?
5 gauss line
What is the primary safety concern associated with gradients?
hearing damage
What can the gradients also cause?
biological responses
(visual flashes/skin sensation/muscle contractions)
What does PNS stand for?
peripheral nerve stimulation
Is PNS reversible?
yes
What is the one safety hazard of RF?
the induction of current in conductors in the magnet bore (patient burns)
What does SAR stand for?
specific absorption rate
What is SAR measured in?
watts/kilogram
What’s the SAR that can pose significant risk for the whole body?
4.0 W/Kg
What’s the SAR that can pose significant risk for the head-only?
3.0 W/Kg
What are the 2 factors needed to calculate SAR?
- weight
- age
What is the only authoritative source for the MRI safety for an implant?
implant manufacturer
Cardiac Pacemaker?
unsafe
