Exam (elaborations)
MRSO RADIO FREQUENCY MODULE 4 QUESTIONS AND ANSWERS
- Course
- Institution
MRSO RADIO FREQUENCY MODULE 4 QUESTIONS AND ANSWERS
[Show more]
Content preview
Name: Score:91 Multiple choice questions
Term 1 of 91
Over half of reports of patient injuries are the result of
UNRELATED to SAR or SED
Patients can and have been burned at low SAR values
RF-related burns
Mostly conductive materials followed by bore contact
can differ significantly at different field strengths
UNRELATED to SAR... although the higher the SAR, the more profound the
consequences
Term 2 of 91
SAR is the
ABSORPTION of RF into the body/tissues
body part and tissue
each vendor uses different algorithm
RATE of RF exposure and absorption
,Term 3 of 91
How patient dissipates RF power
cooling.
If the input is greater than the output, heating occurs.
Normal: 2-10 W/kg
1st Level: 4-10 W/kg
2nd Level: >(4-10) W/kg
Normal: 3.2 W/kg
1st Level: 3.2 W/kg
2nd Level: >3.2 W/kg
within the volume of the RF transmit coil. This is a thermogenic process.
Term 4 of 91
Head SAR per operating mode (6 min):
UNRELATED to SAR... although the higher the SAR, the more profound the
consequences
iron oxide-based ink
(not enough information regarding neon tattoos)
Normal: 3.2 W/kg
1st Level: 3.2 W/kg
2nd Level: >3.2 W/kg
Normal: 2 W/kg
1st Level: 4 W/kg
2nd Level: >4 W/kg
,Term 5 of 91
Burns from conductive metals
-field strength
-RF frequency / coil
-scan parameters: type, # RF pulses, TR, # of slices per TR
-pt characteristics: weight, height, body part
-assumed tissue conductivity
UNRELATED to SAR... although the higher the SAR, the more profound the
consequences
-no skin to skin contact
-do not create loops with coil cables
-have coil cables exit as close to center of bore as possible
-pad between coil cable and patient
-items with metallic backing (drug patches, space blanket)
-ekg electrodes
-fabrics containing metallic fibers (copper fibers, stump shrinker)
If within volume of transmit coil
Term 6 of 91
Elongated Conductors with high risk of heating at 1.5T:
differences in resonant wavelength.
(length of lead matches wavelength)
(wavelength longer at lower field strengths)
muscle
0.5-1.0 cm of padding
not sheet or blanket
25-30 cm
, Term 7 of 91
Purpose of RF (B1) field
tuning components
magnetic field and electric field
receive only
excite hydrogen protons
short bursts (pulses)
Term 8 of 91
Near-field burns
excite hydrogen protons
contact with bore wall
watts/kg
closest to patient inside bore behind thin cover
Term 9 of 91
Cause of tissue heating
-research mode
-can not be used currently, clinically
-transmit only
-receive only
-transmit/receive
Magnetic induction results in eddy currents of conductive tissue
magnetic induction
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller selftest. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $9.00. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
72042 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now