MRSO UPDATED EXAMS STUDY GUIDE ALL
QUESTIONS AND ANSWERS SURE A+
✔✔Static Magnetic Field General Public Exposure Limits - ✔✔400mT
✔✔FDA Limits for Static Magnetic Field - ✔✔< 1 month old - 4T
>1 month old - 8T
✔✔Exposure to Static Magnetic Field of >4T - ✔✔Requires approval.
✔✔Time Varying Gradient Field Concerns - ✔✔Electrical induction due to principle of
Faraday's Law.
Cardiac Fibrilation (not reported).
Diaphragm Spasm - cause difficulty breathing.
Brain
Peripheral Nerve Stimulation - limited to the comfort of the patient.
✔✔Time-Varying Gradient Field Normal Operating Mode Limits - ✔✔IEC/FDA
,Normal Operating Mode
- 80% of the maximum dB/dt exposure.
= +1.0 * rb(1+0.36/teff)
✔✔Time-Varying Gradient Field First Level Mode Limits - ✔✔IEC/FDA
100% of the maxiumum dB/dt
= 0.8 *rb(1+0.36/teff)
✔✔Time-Varying Gradient Field Occupational Exposure Limits - ✔✔ICNRP
- restrictions are limited to 100kHz
IEC
- Limits to peripheral nerve stimulation.
✔✔Time-Varying RF Field Concerns - ✔✔The deposit of Heat (measured in SAR).
Localized Heating to: Eyes, Fetus, & Testicles.
RF Burning.
✔✔Time-Varying RF Field Temperature Increase Limits - ✔✔FDA
- Whole body Exposure <1* Celsius.
✔✔Time-Varying RF Field Heating Limits Normal Operating Mode - ✔✔Increase in core
temperature to 0.5* Celsius
Increase in whole body SAR to less than 2W/kg
Head SAR less than or equal to 3.2 W/kg
✔✔Time-Varying RF Field Heating Limits First Level Mode - ✔✔Increase in core
temperature to 1* Celsius.
Increase in whole body SAR to less than 4W/kg.
Head SAR less than or equal to 3.2 W/kg.
✔✔Time-Varying RF Field Heating Limits Second Level Mode - ✔✔Increase in core
temperature to greater than 1* Celsius.
Increase in whole body SAR to greater than 4W/kg.
, Head SAR less than or equal to greater than 3.2 W/kg.
✔✔Localized Transmit-Receive Coil Heating Limits for Normal Mode - ✔✔FDA/IEC
SAR equal to or less than 10W/kg in the head or trunk (orbits limited to 1* Celsius).
SAR equal to or less than 20W/kg in extremities.
✔✔Localized Transmit-Receive Coil Heating Limits for First Level Mode - ✔✔FDA/IEC
SAR equal to or less than 20W/kg in the head or trunk (orbits limited to 1* Celsius).
SAR equal to or less than 40W/kg in extremities.
✔✔Localized Transmit-Receive Coil Heating Limits for Second Level Mode -
✔✔FDA/IEC
SAR greater than 20W/kg in the head or trunk (orbits limited to 1* Celsius).
SAR greater than 40W/kg in extremities.
✔✔Time-Varying RF Field Occupational Exposure Limits - ✔✔IEC
- 4W/kg SAR
ICNIRP
- 0.4 W/kg SAR
- 61 V/m
- 0.16 A/m
- 0.2 mT
- 10 W/m^2
✔✔Pregnancy Concerns to Static Magnetic Field - ✔✔No adverse effects noted to date.
✔✔Pregnancy Concerns to Time-Varying RF Field - ✔✔Some affect thave been noted
at heating greater than 39* Celsius
✔✔Pregnancy Concerns to Time-Varying Gradient Field - ✔✔Noise production is a
concern
✔✔ICNIRP Pregnancy Concerns - ✔✔Limit RF heating to < .5* Celcius.
No Gadolinium given.
Pregnant MR Tech cannot be in zone IV during data acquisition.
QUESTIONS AND ANSWERS SURE A+
✔✔Static Magnetic Field General Public Exposure Limits - ✔✔400mT
✔✔FDA Limits for Static Magnetic Field - ✔✔< 1 month old - 4T
>1 month old - 8T
✔✔Exposure to Static Magnetic Field of >4T - ✔✔Requires approval.
✔✔Time Varying Gradient Field Concerns - ✔✔Electrical induction due to principle of
Faraday's Law.
Cardiac Fibrilation (not reported).
Diaphragm Spasm - cause difficulty breathing.
Brain
Peripheral Nerve Stimulation - limited to the comfort of the patient.
✔✔Time-Varying Gradient Field Normal Operating Mode Limits - ✔✔IEC/FDA
,Normal Operating Mode
- 80% of the maximum dB/dt exposure.
= +1.0 * rb(1+0.36/teff)
✔✔Time-Varying Gradient Field First Level Mode Limits - ✔✔IEC/FDA
100% of the maxiumum dB/dt
= 0.8 *rb(1+0.36/teff)
✔✔Time-Varying Gradient Field Occupational Exposure Limits - ✔✔ICNRP
- restrictions are limited to 100kHz
IEC
- Limits to peripheral nerve stimulation.
✔✔Time-Varying RF Field Concerns - ✔✔The deposit of Heat (measured in SAR).
Localized Heating to: Eyes, Fetus, & Testicles.
RF Burning.
✔✔Time-Varying RF Field Temperature Increase Limits - ✔✔FDA
- Whole body Exposure <1* Celsius.
✔✔Time-Varying RF Field Heating Limits Normal Operating Mode - ✔✔Increase in core
temperature to 0.5* Celsius
Increase in whole body SAR to less than 2W/kg
Head SAR less than or equal to 3.2 W/kg
✔✔Time-Varying RF Field Heating Limits First Level Mode - ✔✔Increase in core
temperature to 1* Celsius.
Increase in whole body SAR to less than 4W/kg.
Head SAR less than or equal to 3.2 W/kg.
✔✔Time-Varying RF Field Heating Limits Second Level Mode - ✔✔Increase in core
temperature to greater than 1* Celsius.
Increase in whole body SAR to greater than 4W/kg.
, Head SAR less than or equal to greater than 3.2 W/kg.
✔✔Localized Transmit-Receive Coil Heating Limits for Normal Mode - ✔✔FDA/IEC
SAR equal to or less than 10W/kg in the head or trunk (orbits limited to 1* Celsius).
SAR equal to or less than 20W/kg in extremities.
✔✔Localized Transmit-Receive Coil Heating Limits for First Level Mode - ✔✔FDA/IEC
SAR equal to or less than 20W/kg in the head or trunk (orbits limited to 1* Celsius).
SAR equal to or less than 40W/kg in extremities.
✔✔Localized Transmit-Receive Coil Heating Limits for Second Level Mode -
✔✔FDA/IEC
SAR greater than 20W/kg in the head or trunk (orbits limited to 1* Celsius).
SAR greater than 40W/kg in extremities.
✔✔Time-Varying RF Field Occupational Exposure Limits - ✔✔IEC
- 4W/kg SAR
ICNIRP
- 0.4 W/kg SAR
- 61 V/m
- 0.16 A/m
- 0.2 mT
- 10 W/m^2
✔✔Pregnancy Concerns to Static Magnetic Field - ✔✔No adverse effects noted to date.
✔✔Pregnancy Concerns to Time-Varying RF Field - ✔✔Some affect thave been noted
at heating greater than 39* Celsius
✔✔Pregnancy Concerns to Time-Varying Gradient Field - ✔✔Noise production is a
concern
✔✔ICNIRP Pregnancy Concerns - ✔✔Limit RF heating to < .5* Celcius.
No Gadolinium given.
Pregnant MR Tech cannot be in zone IV during data acquisition.
