MRI CHAPTER 4 ADDITONAL SAFETY INFO Flashcards
How many zones of safety are there?
4
Zone I
Zone II
Zone III
Zone IV
What is Zone I?
area outside the MR facility which is freely accessible to the public
What is Zone II?
an area between full public access and the more restricted areas of the MRI Facility
What is Zone III?
the area where access by unscreened non mri personnel or ferromagnetic objects could result in serious injury or even death
-the mr control room
-access to Zone III & the area within Zone III is to be controlled by, and under the supervision of MR personnel
What is Zone IV?
the scan room
MR personnel are separated into
Level I and Level II personnel
What is Level I personnel?
those who have passed minimal safety education to ensure their own safety as they work within Zone III
What is Level II personnel?
those who have more extensively trained and educated in the broader aspects of MR safety issues, including issues related to the potential for thermal loading or burns and direct neuromuscular excitation
Screening for patient and non-MR personnel is take place outside
Zone III
Only ____personnel may allow non-MR personnel access into Zone IV
Level II
While in Zone IV, non-MR personnel are to be:
directly supervised and accompanied by Level II personnel
True or False: if there is a medical emergency, the patient is to first be removed from Zone IV to a predetermined MRI safe location.
true. the emergent removal of the patient must be accomplished before emergency personnel can respond
The current labeling (recognized and used by the FDA) for implants and devices places items into one of three categories:
MR Safe
MR Unsafe
MR Conditional
MR Safe
items which pose no known hazards in all MRI environments. examples include glass, wood, and plastic
MRI unsafe
- items known to pose hazards in all MRI environments. examples include ferromagnetic objects such as standard o2 cylinders
MR conditional
An item that has been demonstrated to pose no known hazards in a specified MRI environment with specified conditions of use.
any device that is metal, magnetically, or electrically activated cannot be labeled as MR Safe. if under certain conditions, it may brought into MRI environment, it would be labeled as MR conditional
The safety of any implant or device is based on specific conditions of use which can include:
field strength
RF power limits
gradient switching limits
and/or spatial field gradient limits
when screening a patient for intraocular ferrous foreign body, the accepted standard is to:
obtain radiographs of the orbits
Patient Monitoring
patients should be monitored verbally and visually during the scan
patients who require physiologic monitoring
patients who cannot communicate
language barriers
sedated pts
those with weak voices
pts w/diminished mental capacity
pts at risk for an adverse event following injection of gad based contrast
the most common method used for physiologic monitoring is
fiber pulse oximetry
True or False. the FDAs stance of safety of MR imaging during pregnancy has not been proven
true. it doesn’t mean its safe, doesn’t mean its unsafe, it means there is no data
True or False the use of gadolinium-based MR contrast in pregnant patients is generally avoided.
true
in the event of a failure of the primary ventilation system during a quench,
the helium gas can quickly fill the scan room.
if scan room door opens inward & is shut during a quench there would likely be such a large increase in pressure that one would be unable to open the scan room door
if anyone were in the scan room during a quench and failure of the primary vent system they would:
experience ruptured ear drums
while breathing helium will not cause immediate death,
helium does replace O2 so continued breathing of helium would result in asphyxiation.
