Study Guide for MRI CAMRT Exam Questions and Answers Latest Updated
8 views 0 purchase
Module
MRI CAMRT
Institution
MRI CAMRT
Study Guide for MRI CAMRT Exam
Questions and Answers Latest Updated
Is SNR proportional or inversely proportional to voxel volume - CORRECT ANSWERProportional
3 fields used in MRI - CORRECT ANSWER--static magnetic field
-TVMF (gradient field)
-RF field
3 main types of magnets used - CORRECT...
is snr proportional or inversely proportional to v
3 main types of magnets used
Written for
MRI CAMRT
MRI CAMRT
Seller
Follow
TIFFACADEMICS
Reviews received
Content preview
Study Guide for MRI CAMRT Exam
Questions and Answers Latest Updated
Is SNR proportional or inversely proportional to voxel volume - CORRECT ANSWER-
Proportional
3 fields used in MRI - CORRECT ANSWER--static magnetic field
-TVMF (gradient field)
-RF field
3 main types of magnets used - CORRECT ANSWER--Superconducting (most
common_
-Resistive
-Permanent
FDA limits for the 3 fields in MRI - CORRECT ANSWER-Static field: 2T
TVMF: 3T/s
RF field:
- does not cause an increase in temperature of more than .5 deg C or any body part of 1
deg C
-SAR does not exceed 1W/kg avg over 25% of whole body for longer than 15mins
-SAR does not exceed 2W/kg avg over 25% of whole body for durations of 15mins or
less
Eddy currents are caused by - CORRECT ANSWER-TVMF (gradients)
What are Eddy Currents - CORRECT ANSWER-Small currents induced in the body via
the TVMF
Biological effects of the TVMF - CORRECT ANSWER--Fibrillation
-Electroshock
-Visual phosphenes
-Peripheral nerve stimulation
SAR meaning and units - CORRECT ANSWER-Specific Absorption Rate
W/kg- Watts/kilogram
Which field is responsible for tissue heating and temperature increase - CORRECT
ANSWER-The RF field
How are cardiac pacemakers affected in MRI - CORRECT ANSWER-Affected by all 3
fields
,-Static field affects the operation and also exerts torque
-TVMF and RF field can interfere with circuitry
3 types of ferromagnetic materials? - CORRECT ANSWER-iron, cobalt, nickel
Level 2 MR Personnel - CORRECT ANSWER-Those more extensively trained and
educated in MRI safety
How many times should a non emergent patient be screened - CORRECT ANSWER-
Twice, once verbally with a level 2 MR Tech
How should emergent patients and their non MR personnel be screened - CORRECT
ANSWER-Once
How should unconscious/ unresponsive patients be screened - CORRECT ANSWER--
A family member should fill out the screening form
-If no reliable history can be obtained and MR exam cannot wait they must undergo
plain film radiography of head/neck, chest, abdomen/pelvis, upper arms and thighs
How should children and teens be screened - CORRECT ANSWER-Twice, once in front
of parents and once without
MRI and pregnant patients - CORRECT ANSWER-No known harmful effects but risk vs
benefit assessment should be made
MRI contrast and pregnant patients - CORRECT ANSWER-Should not be routinely
given to pregnant patients but risk vs benefit assessment needed
What is the spatial field gradient - CORRECT ANSWER-The variance in the fixed static
field surrounding the scanner, the manufacturerer supplies a SFG map
Lenz forces - CORRECT ANSWER-Faradays law states that a changing magnetic field
will induce a current in a conductor, Lenzs law states that the induced current will
generate a secondary field that opposes the original field
Normal respiratory ranges - CORRECT ANSWER-Adult: 15-20 breaths per minute
Infant: 30-60 breaths per minute
Normal pulse oximetry - CORRECT ANSWER-95%-100%
Tachycardia - CORRECT ANSWER-Fast heart rate over 100 bpm
Bradycardia - CORRECT ANSWER-Slow heart rate less than 60 bpm
Spots to get a pulse reading - CORRECT ANSWER--Radial (wrist)
-Carotid (neck)
-Popliteal (knee)
-Temporal (head)
-Brachial (elbow)
-Dorsalis pedis (foot)
-Femoral(leg)
Most accurate spot for pulse rate in infants - CORRECT ANSWER-Apical over apex of
the heart
Normal BP ranges - CORRECT ANSWER-Adult: 80-120mmHg/60-80mmHg
Child: 90-120mmHg/50-70mmHg
Infant: 85-130mmHg/45-85mmHg
3 types of motion in an atom - CORRECT ANSWER-(1) Electron on its axis (2) Electron
around the nucleus (3) Nucleus on its axis
Isotope of hydrogen - CORRECT ANSWER-protium (MR active nuclei)
True or false: Hydrogen nuclei only align themselves to the field in 2 directions -
CORRECT ANSWER-True
As Bo increases what happens to the difference in energy between high and low energy
states - CORRECT ANSWER-increases - more spins aligned to Bo means larger NMV
which means more signal
Larmour frequency - CORRECT ANSWER-The precessional or resonant frequency
(w0) of a nuclear spin when it is placed in an external magnetic field.
It is related to the magnetic field (Bₒ) by the Larmor equation:
Wₒ=ϒ * B ₒ
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 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 TIFFACADEMICS. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £14.54. You're not tied to anything after your purchase.
