CAMRT MRI EXAMINATION MANUAL 2025/2026
QUESTIONS WITH ANSWERS GRADED A+
✔✔Symptoms of mild contrast reaction - ✔✔-Nasal congestion, sneezing
-Nausea
-Headache, dizziness, anxiety
-Altered taste
-Flushing
-Some hives
✔✔Symptoms of moderate contrast reaction - ✔✔-Facial edema
-Wheezing mild
-Hoarseness without dyspnea
-Diffuse hives
✔✔Symptoms of severe contrast reaction - ✔✔-Facial edema with dyspnea
-Throat swelling with stridor
-Wheezing significant
-Racing heart
-Convulsions
-Widespread hives
✔✔K space: Cartesian filling - ✔✔k space is filled linear from top to bottom or bottom to
top. Most common method
✔✔Nyquist Theorem - ✔✔Describes the method of converting analog signals into digital
format by sampling at twice the highest frequency
✔✔When Nyquist principles are obeyed this parameter has the same value of the digital
sampling frequency - ✔✔The receiver bandwidth
✔✔When RBW is high, the sampling time is ______ - ✔✔Shorter - data are collected
more quickly. This means the TE is shorter as the peak of the echo occurs half way
through the sampling time
✔✔2 parameters that change the sampling window - ✔✔RBW and frequency matrix
which therefore impacts the minimum TE
✔✔Centre lines of k space contains ____ signal and ____ resolution - ✔✔High, Low
✔✔Outer lines of k space contain ____ signal and ____ resolution - ✔✔Low, High
✔✔FDA limits for static fields, TVMFs, and RF fields - ✔✔Static field- 2T
TVMF- 3T/s
, RF fields- does not cause increase of body temp of more than 0.5deg C and any part of
the body of more than 1deg C. SAR should not exceed 1W/kg over 25% of whole body
mass for more than 15 min and 2W/kg over 25% of whole body mass for less than 15
min
✔✔Partial, fractional averaging, or half Fourier method of filling k space - ✔✔Negative
and positive halves of k space on each side of the phase axis (vertical) are symmetrical.
Only 75% of k space is filled, which results in faster scan time but less signal.
Used in volume imaging, truncation artifact more likely to occur.
✔✔Partial echo - filling k space - ✔✔Negative and positive halves of k space in the
frequency direction (horizontal) are symmetrical. Only part of the echo is read, the peak
of the echo is moved to occur sooner so only the peak and dephasing portion is read
and only the right side of k space is filled, but the left side is extrapolated.
This is used in PD and T1 weighting when a short TR is needed and the minimum TE is
limited
✔✔How k space is filled with parallel imaging - ✔✔Fills multiple lines of k space per TR.
These lines are acquired by assigning them to certain coils that are coupled together in
an array, these coils are designed with multiple coil elements. Scan time is reduced by
the acceleration factor that is equal to the number of coil elements. Can improve
resolution but decreases signal.
✔✔Single shot and filling k space - ✔✔All lines of k space are filled at once, if phase
matrix of 128 required then 128 echoes are produced. Phase encode gradient "blips"
and lines are filled linearly. No TR value.
✔✔Spiral k space filling - ✔✔The readout gradient oscillates to fill lines from left to right
and then right to left, and K space filling begins at the center; the phase gradient must
also oscillate to fill a line in the top half followed by a line in the bottom half. All lines
filled in a single shot.
✔✔Propeller or radial k space filling - ✔✔Data points are acquired in strips and rotate
around the central axis. Reduces motion artifacts but scan time is increased.
✔✔Factors that affect SNR - ✔✔1. Mag. field strength
2. PD
3. Voxel Volume
4. TR, TE, FA
5. NEX
6. R. bandwidth
7. Coil type
QUESTIONS WITH ANSWERS GRADED A+
✔✔Symptoms of mild contrast reaction - ✔✔-Nasal congestion, sneezing
-Nausea
-Headache, dizziness, anxiety
-Altered taste
-Flushing
-Some hives
✔✔Symptoms of moderate contrast reaction - ✔✔-Facial edema
-Wheezing mild
-Hoarseness without dyspnea
-Diffuse hives
✔✔Symptoms of severe contrast reaction - ✔✔-Facial edema with dyspnea
-Throat swelling with stridor
-Wheezing significant
-Racing heart
-Convulsions
-Widespread hives
✔✔K space: Cartesian filling - ✔✔k space is filled linear from top to bottom or bottom to
top. Most common method
✔✔Nyquist Theorem - ✔✔Describes the method of converting analog signals into digital
format by sampling at twice the highest frequency
✔✔When Nyquist principles are obeyed this parameter has the same value of the digital
sampling frequency - ✔✔The receiver bandwidth
✔✔When RBW is high, the sampling time is ______ - ✔✔Shorter - data are collected
more quickly. This means the TE is shorter as the peak of the echo occurs half way
through the sampling time
✔✔2 parameters that change the sampling window - ✔✔RBW and frequency matrix
which therefore impacts the minimum TE
✔✔Centre lines of k space contains ____ signal and ____ resolution - ✔✔High, Low
✔✔Outer lines of k space contain ____ signal and ____ resolution - ✔✔Low, High
✔✔FDA limits for static fields, TVMFs, and RF fields - ✔✔Static field- 2T
TVMF- 3T/s
, RF fields- does not cause increase of body temp of more than 0.5deg C and any part of
the body of more than 1deg C. SAR should not exceed 1W/kg over 25% of whole body
mass for more than 15 min and 2W/kg over 25% of whole body mass for less than 15
min
✔✔Partial, fractional averaging, or half Fourier method of filling k space - ✔✔Negative
and positive halves of k space on each side of the phase axis (vertical) are symmetrical.
Only 75% of k space is filled, which results in faster scan time but less signal.
Used in volume imaging, truncation artifact more likely to occur.
✔✔Partial echo - filling k space - ✔✔Negative and positive halves of k space in the
frequency direction (horizontal) are symmetrical. Only part of the echo is read, the peak
of the echo is moved to occur sooner so only the peak and dephasing portion is read
and only the right side of k space is filled, but the left side is extrapolated.
This is used in PD and T1 weighting when a short TR is needed and the minimum TE is
limited
✔✔How k space is filled with parallel imaging - ✔✔Fills multiple lines of k space per TR.
These lines are acquired by assigning them to certain coils that are coupled together in
an array, these coils are designed with multiple coil elements. Scan time is reduced by
the acceleration factor that is equal to the number of coil elements. Can improve
resolution but decreases signal.
✔✔Single shot and filling k space - ✔✔All lines of k space are filled at once, if phase
matrix of 128 required then 128 echoes are produced. Phase encode gradient "blips"
and lines are filled linearly. No TR value.
✔✔Spiral k space filling - ✔✔The readout gradient oscillates to fill lines from left to right
and then right to left, and K space filling begins at the center; the phase gradient must
also oscillate to fill a line in the top half followed by a line in the bottom half. All lines
filled in a single shot.
✔✔Propeller or radial k space filling - ✔✔Data points are acquired in strips and rotate
around the central axis. Reduces motion artifacts but scan time is increased.
✔✔Factors that affect SNR - ✔✔1. Mag. field strength
2. PD
3. Voxel Volume
4. TR, TE, FA
5. NEX
6. R. bandwidth
7. Coil type
