2026 MRSE LATEST EXAMS TEST PAPER
QUESTIONS AND ANSWERS SURE A+
✔✔What is B1+rms? - ✔✔Describes the useful energy transmitted to our patient over a
10-second average
✔✔What is chronobase/chonaxie and what is a typical value? - ✔✔2x the minimum time
that will cause stimulation in a patient (0.36 seconds)
✔✔RF flip angle (a) formula - ✔✔a = 2π x y x B1 x T, where y = frequency, B1 =
gradient magnetic flux density, T = ?
✔✔What kinds of sequences pose the highest risk for Peripheral Nerve Stimulation
(PNS)? - ✔✔Localizer, Echo Planar Imaging (EPI) such as DWI, and steady state such
as GRASS (less than DWI)
✔✔What is the difference between maximum slew rate and total slew rate? -
✔✔maximum slew rate = slew rate per gradient coil pair
total slew rate = slew rate produced from multiple gradient coil pairs
✔✔How much do earplugs reduce noise, in decibels? - ✔✔10-30 dB
, ✔✔What parameters can be changed to reduce noise? - ✔✔SE instead of GE
sequences (more spaced-out G activations), Increasing E spacing, Increasing
frequency encoding (adds more data points and increases E spacing), Decreasing BW
(will increase sample time and E spacing), increasing TE (increases E space b/c TE is
always in center of acquisition window). Changes that reduce PNS will also reduce
noise
✔✔Noise Reduction Rating (NRR) Calculation - ✔✔If exposed to 80 dB and wearing
earplugs with an NRR of 33 dB, experience an A-weighting of 67 dB (80 dB - 13 dB). A
= (NRR - 7)/2
✔✔Typical dB ratings for rusting leaves, normal conversation, and a jackhammer -
✔✔rustling leaves = 10 dB. Normal conversation = 54 dB. Jackhammer = 100 dB
✔✔Definition of pascal - ✔✔1 pascal = newton/meter^2 [n/m^2]. 1 pascal = 94 dB SPL
✔✔What is specific energy dose (SED)? - ✔✔The amount of energy per mass for the
total exam, measured in kJ/kg
✔✔What are limits for specific energy dose (SED)? - ✔✔What the manufacturer deems
necessary. Old limits were 14.4 kJ/kg (240 W*min./kg).
✔✔Specific energy dose (SED) formula - ✔✔SED = SARxt1 + SARxt2... where t = time
in s
✔✔Specific absorption rate (SAR) formula - ✔✔Bo^2 x Flip angle^2 x RF duty cycle x
Patient size, where Bo = static field magnetic flux density
✔✔Formula for energy (E) in terms of power (P) and time (t) - ✔✔E[J] = P[W] x t[s]
✔✔What is the significance of the old specific energy dose (SED) limits and how can
they be reached? - ✔✔14.4 kJ/kg is a level of heating that will increase a pt's core
temperature w/ normal thermal regulation to 43 degrees C, enough to cause damage.
Can be achieved by scanning continuously in 1st level controlled operation mode for 1 h
or 2 h in normal operation mode. For pts w/ compromised thermal regulation, a level of
100 W*min./kg or 6 kJ/kg is enough to cause tissue damage. Can be achieved by by
scanning continuously in 1st level-controlled operation mode for 25 min or 50 min in
normal operation mode
✔✔A increase of 6 dB, 10 dB, 20 dB (auditory) represents an increase in power __x,
__x, __x - ✔✔2x, 3x, 10x
✔✔A larger patient mass will have a (larger/smaller) energy deposition from heating -
✔✔larger
QUESTIONS AND ANSWERS SURE A+
✔✔What is B1+rms? - ✔✔Describes the useful energy transmitted to our patient over a
10-second average
✔✔What is chronobase/chonaxie and what is a typical value? - ✔✔2x the minimum time
that will cause stimulation in a patient (0.36 seconds)
✔✔RF flip angle (a) formula - ✔✔a = 2π x y x B1 x T, where y = frequency, B1 =
gradient magnetic flux density, T = ?
✔✔What kinds of sequences pose the highest risk for Peripheral Nerve Stimulation
(PNS)? - ✔✔Localizer, Echo Planar Imaging (EPI) such as DWI, and steady state such
as GRASS (less than DWI)
✔✔What is the difference between maximum slew rate and total slew rate? -
✔✔maximum slew rate = slew rate per gradient coil pair
total slew rate = slew rate produced from multiple gradient coil pairs
✔✔How much do earplugs reduce noise, in decibels? - ✔✔10-30 dB
, ✔✔What parameters can be changed to reduce noise? - ✔✔SE instead of GE
sequences (more spaced-out G activations), Increasing E spacing, Increasing
frequency encoding (adds more data points and increases E spacing), Decreasing BW
(will increase sample time and E spacing), increasing TE (increases E space b/c TE is
always in center of acquisition window). Changes that reduce PNS will also reduce
noise
✔✔Noise Reduction Rating (NRR) Calculation - ✔✔If exposed to 80 dB and wearing
earplugs with an NRR of 33 dB, experience an A-weighting of 67 dB (80 dB - 13 dB). A
= (NRR - 7)/2
✔✔Typical dB ratings for rusting leaves, normal conversation, and a jackhammer -
✔✔rustling leaves = 10 dB. Normal conversation = 54 dB. Jackhammer = 100 dB
✔✔Definition of pascal - ✔✔1 pascal = newton/meter^2 [n/m^2]. 1 pascal = 94 dB SPL
✔✔What is specific energy dose (SED)? - ✔✔The amount of energy per mass for the
total exam, measured in kJ/kg
✔✔What are limits for specific energy dose (SED)? - ✔✔What the manufacturer deems
necessary. Old limits were 14.4 kJ/kg (240 W*min./kg).
✔✔Specific energy dose (SED) formula - ✔✔SED = SARxt1 + SARxt2... where t = time
in s
✔✔Specific absorption rate (SAR) formula - ✔✔Bo^2 x Flip angle^2 x RF duty cycle x
Patient size, where Bo = static field magnetic flux density
✔✔Formula for energy (E) in terms of power (P) and time (t) - ✔✔E[J] = P[W] x t[s]
✔✔What is the significance of the old specific energy dose (SED) limits and how can
they be reached? - ✔✔14.4 kJ/kg is a level of heating that will increase a pt's core
temperature w/ normal thermal regulation to 43 degrees C, enough to cause damage.
Can be achieved by scanning continuously in 1st level controlled operation mode for 1 h
or 2 h in normal operation mode. For pts w/ compromised thermal regulation, a level of
100 W*min./kg or 6 kJ/kg is enough to cause tissue damage. Can be achieved by by
scanning continuously in 1st level-controlled operation mode for 25 min or 50 min in
normal operation mode
✔✔A increase of 6 dB, 10 dB, 20 dB (auditory) represents an increase in power __x,
__x, __x - ✔✔2x, 3x, 10x
✔✔A larger patient mass will have a (larger/smaller) energy deposition from heating -
✔✔larger
