©SIRJOEL EXAM SOLUTIONS
12/3/2024 11:27AM
MRI CAMRT Exam Questions With Correct
Answers
Is SNR proportional or inversely proportional to voxel volume - answer✔Proportional
3 fields used in MRI - answer✔-static magnetic field
-TVMF (gradient field)
-RF field
3 main types of magnets used - answer✔-Superconducting (most common_
-Resistive
-Permanent
FDA limits for the 3 fields in MRI - 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
, ©SIRJOEL EXAM SOLUTIONS
12/3/2024 11:27AM
-SAR does not exceed 2W/kg avg over 25% of whole body for durations of 15mins or less
Eddy currents are caused by - answer✔TVMF (gradients)
What are Eddy Currents - answer✔Small currents induced in the body via the TVMF
Biological effects of the TVMF - answer✔-Fibrillation
-Electroshock
-Visual phosphenes
-Peripheral nerve stimulation
SAR meaning and units - answer✔Specific Absorption Rate
W/kg- Watts/kilogram
Which field is responsible for tissue heating and temperature increase - answer✔The RF field
How are cardiac pacemakers affected in MRI - 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? - answer✔iron, cobalt, nickel
, ©SIRJOEL EXAM SOLUTIONS
12/3/2024 11:27AM
Level 1 MR Personnel - answer✔Passed MR safety education requirements
Level 2 MR Personnel - answer✔Those more extensively trained and educated in MRI safety
How many times should a non emergent patient be screened - answer✔Twice, once verbally with
a level 2 MR Tech
How should emergent patients and their non MR personnel be screened - answer✔Once
How should unconscious/ unresponsive patients be screened - 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 - answer✔Twice, once in front of parents and once
without
MRI and pregnant patients - answer✔No known harmful effects but risk vs benefit assessment
should be made
MRI contrast and pregnant patients - answer✔Should not be routinely given to pregnant patients
but risk vs benefit assessment needed
What is the spatial field gradient - answer✔The variance in the fixed static field surrounding the
scanner, the manufacturerer supplies a SFG map
12/3/2024 11:27AM
MRI CAMRT Exam Questions With Correct
Answers
Is SNR proportional or inversely proportional to voxel volume - answer✔Proportional
3 fields used in MRI - answer✔-static magnetic field
-TVMF (gradient field)
-RF field
3 main types of magnets used - answer✔-Superconducting (most common_
-Resistive
-Permanent
FDA limits for the 3 fields in MRI - 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
, ©SIRJOEL EXAM SOLUTIONS
12/3/2024 11:27AM
-SAR does not exceed 2W/kg avg over 25% of whole body for durations of 15mins or less
Eddy currents are caused by - answer✔TVMF (gradients)
What are Eddy Currents - answer✔Small currents induced in the body via the TVMF
Biological effects of the TVMF - answer✔-Fibrillation
-Electroshock
-Visual phosphenes
-Peripheral nerve stimulation
SAR meaning and units - answer✔Specific Absorption Rate
W/kg- Watts/kilogram
Which field is responsible for tissue heating and temperature increase - answer✔The RF field
How are cardiac pacemakers affected in MRI - 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? - answer✔iron, cobalt, nickel
, ©SIRJOEL EXAM SOLUTIONS
12/3/2024 11:27AM
Level 1 MR Personnel - answer✔Passed MR safety education requirements
Level 2 MR Personnel - answer✔Those more extensively trained and educated in MRI safety
How many times should a non emergent patient be screened - answer✔Twice, once verbally with
a level 2 MR Tech
How should emergent patients and their non MR personnel be screened - answer✔Once
How should unconscious/ unresponsive patients be screened - 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 - answer✔Twice, once in front of parents and once
without
MRI and pregnant patients - answer✔No known harmful effects but risk vs benefit assessment
should be made
MRI contrast and pregnant patients - answer✔Should not be routinely given to pregnant patients
but risk vs benefit assessment needed
What is the spatial field gradient - answer✔The variance in the fixed static field surrounding the
scanner, the manufacturerer supplies a SFG map
