2026 MRSE CORE MAIN EXAMS ALL SET
QUESTIONS AND ANSWERS SURE A+
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✔✔When a breath-hold sequence is run and noticeably short (~10 s) scan times are
used, we are allowed to use __x our SAR limit. - ✔✔2x
✔✔IEC static magnetic field limits - ✔✔Normal: 3 T or less
First level: 8 T or less
✔✔What are the gradient limits for FPO? - ✔✔B1+rms max = 3.2 uT
B1 peak max = 30 uT
(dB/dt) peak max = 100 T/s
(dB/dt)+rms max = 56 T/s
✔✔FDA SAR limits - ✔✔Whole Body: 4 W/kg over 15 min
Head: 3 W/kg over 10 min
1g of Tissue in Head or Torso: 8 W/kg over 15 min
1g of Tissue in Extremities: 12 W/kg over 5 min
✔✔FDA limit on peripheral nerve stimulation (PNS) - ✔✔Different for each patient
✔✔FDA limit on auditory noise - ✔✔Same as IEC
, ✔✔FDA limit on gradient field strength - ✔✔Patient pain tolerance
✔✔FDA pregnancy limits - ✔✔none
✔✔Organization that declares objects "MR Safe" - ✔✔ASTM
✔✔Which is not used? "MR Safe, MR Compatible, MR Conditional, MR Unsafe" -
✔✔MR Compatible
✔✔What is the difference between passive and active implants? - ✔✔passive = no
electrical circuitry
✔✔Which property(ies) of the MR can cause battery depletion? - ✔✔gradient field
✔✔Which property(ies) of the MR can cause excess stimulation? - ✔✔gradient field, RF
field
✔✔Which kinds of leads can cause greatest heating? - ✔✔-Abandoned leads
-Capped leads
-Bipolar leads
-Bare leads (rather than insulated)
✔✔Definition of normal, first-level, and second-level modes - ✔✔Normal = 80% of limit,
no distress;
First level = 100% of limit, may cause distress, requires medical supervision
Second level = 120% of limit, likely to cause distress, requires IRB approval, can cause
heart stimulation in patients without implants
✔✔What is the difference between whole body and local SAR? - ✔✔whole body =
receive only coil
local = transmit/receive coil
✔✔What is relaxivity? - ✔✔The amount of T1 shortening produced from a contrast
agent
✔✔What is viscosity? - ✔✔The thickness of a contrast agent
✔✔What is transmetallation? - ✔✔The process of a ligand losing a gadolinium ion and
picking up another metal ion (zinc). Gadolinium will attach to phosphates
✔✔What is chelation? - ✔✔A process of binding a metal ion (gadolinium ion) to a
molecule so that it can be quickly released from the body
QUESTIONS AND ANSWERS SURE A+
\
✔✔When a breath-hold sequence is run and noticeably short (~10 s) scan times are
used, we are allowed to use __x our SAR limit. - ✔✔2x
✔✔IEC static magnetic field limits - ✔✔Normal: 3 T or less
First level: 8 T or less
✔✔What are the gradient limits for FPO? - ✔✔B1+rms max = 3.2 uT
B1 peak max = 30 uT
(dB/dt) peak max = 100 T/s
(dB/dt)+rms max = 56 T/s
✔✔FDA SAR limits - ✔✔Whole Body: 4 W/kg over 15 min
Head: 3 W/kg over 10 min
1g of Tissue in Head or Torso: 8 W/kg over 15 min
1g of Tissue in Extremities: 12 W/kg over 5 min
✔✔FDA limit on peripheral nerve stimulation (PNS) - ✔✔Different for each patient
✔✔FDA limit on auditory noise - ✔✔Same as IEC
, ✔✔FDA limit on gradient field strength - ✔✔Patient pain tolerance
✔✔FDA pregnancy limits - ✔✔none
✔✔Organization that declares objects "MR Safe" - ✔✔ASTM
✔✔Which is not used? "MR Safe, MR Compatible, MR Conditional, MR Unsafe" -
✔✔MR Compatible
✔✔What is the difference between passive and active implants? - ✔✔passive = no
electrical circuitry
✔✔Which property(ies) of the MR can cause battery depletion? - ✔✔gradient field
✔✔Which property(ies) of the MR can cause excess stimulation? - ✔✔gradient field, RF
field
✔✔Which kinds of leads can cause greatest heating? - ✔✔-Abandoned leads
-Capped leads
-Bipolar leads
-Bare leads (rather than insulated)
✔✔Definition of normal, first-level, and second-level modes - ✔✔Normal = 80% of limit,
no distress;
First level = 100% of limit, may cause distress, requires medical supervision
Second level = 120% of limit, likely to cause distress, requires IRB approval, can cause
heart stimulation in patients without implants
✔✔What is the difference between whole body and local SAR? - ✔✔whole body =
receive only coil
local = transmit/receive coil
✔✔What is relaxivity? - ✔✔The amount of T1 shortening produced from a contrast
agent
✔✔What is viscosity? - ✔✔The thickness of a contrast agent
✔✔What is transmetallation? - ✔✔The process of a ligand losing a gadolinium ion and
picking up another metal ion (zinc). Gadolinium will attach to phosphates
✔✔What is chelation? - ✔✔A process of binding a metal ion (gadolinium ion) to a
molecule so that it can be quickly released from the body
