CAMRT MRI TEST 2025/2026 QUESTIONS WITH ANSWERS
GRADED A+
✔✔Tethered cord syndrome - ✔✔-Tail end of spinal cord is stretched from compression,
being trapped w/ fatty mass, or developmental abnormality
-Signs: hairy patch of skin, hemangioma, dimple of lower spine
-Symptoms: Diff w/ bowel/bladder, gait disturbances, deformities of feet
Conus at abnormally low position below L2, thickened filum terminale
✔✔choledochal cyst - ✔✔Cystic growth on the common duct that may cause
obstruction
✔✔J coupling - ✔✔causes an increase in the T2 decay time of fat when multiple RF
pulses are applied as in fast spin echo
✔✔Ss tse - ✔✔Half Fourier imaging, t2-W, less snr
✔✔Lorentz force - ✔✔sum of the electrostatic and magnetic forces acting on a body.
Causes vibrations in gradient coils=noise.
✔✔What factors affect time of flight phenomena - ✔✔TE, slice thickness, velocity of flow
✔✔Ways to reduce magnetic susceptibility - ✔✔Use spin echo ideally tse, remove
metal, use short TE, use a wide receiver bandwidth as this reduces the TE
✔✔3D vs 2D imaging - ✔✔3D have smaller voxels, higher spatial resolution but spins
become saturated as they traverse a thick slab. This precludes venography as slow flow
will saturate quickly
✔✔Consequences of decreasing tr - ✔✔Shorter scan time, increased T1 weighting,
fewer slices, decreased snr
✔✔Consequences of decreasing phase matrix - ✔✔Increased spatial resolution,
decreased snr, shorter scan time, truncation artifact
✔✔3 consequences of decreasing the received bandwidth - ✔✔More snr, more
chemical shift, longer te
✔✔Why does the TE increase when high resolution parameters are selected -
✔✔Because high resolution parameters lead to longer rise times, gradients take longer
to apply which limits minimum TE
✔✔Ways to increase resolution without affecting scan time - ✔✔Increase frequency
matrix, use asymmetric FOV
,✔✔What happens in k space when the phase fov is doubled - ✔✔The incremental step
between each line is halved.
✔✔What determines polarity of a gradient - ✔✔The direction of current through gradient
coil
✔✔Why does the system default the phase encoding axis along the shortest axis of
anatomy - ✔✔To reduce aliaising
✔✔Compensatory gradients? - ✔✔All gradients produce a change of frequency and a
change of phase. Phase change is required for phase encoding but NOT wanted for
frequency or slice select, therefore extra compensatory gradients are applied to
rephrase the spins so there is no net phase change
✔✔Dead time - ✔✔Time the system is attending to all other slices in the stack after
exciting the first slice
✔✔Perfusion imaging - ✔✔used in conjunction with diffusion imaging, also relies on fast
scanning techniques and the rapid infusion of an intravenous contrast agent
(gadolinium) to visualize the transit time of blood through a specific area. GRE
✔✔Diffusion Tensor Imaging (DTI) - ✔✔a technique used to produce images of the
brain that shows connections among different regions. Measured along three orthogonal
directions. Used for napping white matter Tracts as functional anisotropy maps or
tractography images (the weird images with colours)
✔✔Fomite - ✔✔Any inanimate object to which infectious material adheres and can be
transmitted.
✔✔A narrow receive bandwidth does what to susceptibility artifact - ✔✔Increased
susceptibility artifact
✔✔What orientation best sees tear of collateral ligaments of knee - ✔✔Coronal
✔✔Best plane to see tfcc tears = - ✔✔Coronal
✔✔Hemangioma in liver are best visualized in what phase after contrast injection -
✔✔Delayed images
✔✔Reducing flip angle causes what change in image contrast - ✔✔Less T1 information
, ✔✔Permanent magnets with a vertical magnetic field use surface coils that are -
✔✔Solenoids.the secondary magnetic field B1 created by RG coil must be
perpendicular to the orientation of B0
✔✔A STIR with a T1 of 160ms will null signal from fat at what field strength - ✔✔The T1
of fat at 1.5 Tesla is 240 with a bull point of 160ms
✔✔What elements are ferromagnetic - ✔✔iron, nickel, cobalt, gadolinium
✔✔What is a solenoid electromagnet - ✔✔Magnets that use current passed through the
coils of a wire to generate a magnetic field. Used in closed bore systems
✔✔Active shielding - ✔✔uses additional superconducting coils located at each end of
the main magnet inside the cryostat to shield the system. Bucking coils. Solenoids that
carry current in the opposite direction to reverse the flux.
✔✔Innermost part of the scanner - ✔✔Radio frequency coils - gradient coils - shim coils
- main magnet
✔✔Active shimming - ✔✔____________ is a term used to describe the adjustment of
the current within the shim coils on a per patient or per sequence basis. Uses
electromagnets instead of ferromagnetic shims (as in passive shimming).
✔✔Vertebral body will have __ signal on T1 in presence of fracture infection or
neoplasm - ✔✔Hypointense
✔✔Doubling field strength will do what to snr, and to SAR - ✔✔Double it ; quadruple it.
SAR is proportional to the power of 2 for the resonant frequency
✔✔Sequence best for cardiac imaging? - ✔✔EPI; due to its capability of acquiring
imaging in a fraction of a second
✔✔Two main flow phenomena - ✔✔ESP: hyperintense vessel because inflowing nuclei
do not receive repeated reseated RF pulses
ToF: signal loss
✔✔2D imaging - ✔✔Most common mri acquisition. Fills one line of k space in each slice
before moving on to the next one of k space
✔✔Ways to reduce patient heating - ✔✔Remove sat pulses, increaseTR, decrease slice
number, use appropriate receive coil, avoid trains of 180 pulses, reduce flip angle of
rephasing pulses
GRADED A+
✔✔Tethered cord syndrome - ✔✔-Tail end of spinal cord is stretched from compression,
being trapped w/ fatty mass, or developmental abnormality
-Signs: hairy patch of skin, hemangioma, dimple of lower spine
-Symptoms: Diff w/ bowel/bladder, gait disturbances, deformities of feet
Conus at abnormally low position below L2, thickened filum terminale
✔✔choledochal cyst - ✔✔Cystic growth on the common duct that may cause
obstruction
✔✔J coupling - ✔✔causes an increase in the T2 decay time of fat when multiple RF
pulses are applied as in fast spin echo
✔✔Ss tse - ✔✔Half Fourier imaging, t2-W, less snr
✔✔Lorentz force - ✔✔sum of the electrostatic and magnetic forces acting on a body.
Causes vibrations in gradient coils=noise.
✔✔What factors affect time of flight phenomena - ✔✔TE, slice thickness, velocity of flow
✔✔Ways to reduce magnetic susceptibility - ✔✔Use spin echo ideally tse, remove
metal, use short TE, use a wide receiver bandwidth as this reduces the TE
✔✔3D vs 2D imaging - ✔✔3D have smaller voxels, higher spatial resolution but spins
become saturated as they traverse a thick slab. This precludes venography as slow flow
will saturate quickly
✔✔Consequences of decreasing tr - ✔✔Shorter scan time, increased T1 weighting,
fewer slices, decreased snr
✔✔Consequences of decreasing phase matrix - ✔✔Increased spatial resolution,
decreased snr, shorter scan time, truncation artifact
✔✔3 consequences of decreasing the received bandwidth - ✔✔More snr, more
chemical shift, longer te
✔✔Why does the TE increase when high resolution parameters are selected -
✔✔Because high resolution parameters lead to longer rise times, gradients take longer
to apply which limits minimum TE
✔✔Ways to increase resolution without affecting scan time - ✔✔Increase frequency
matrix, use asymmetric FOV
,✔✔What happens in k space when the phase fov is doubled - ✔✔The incremental step
between each line is halved.
✔✔What determines polarity of a gradient - ✔✔The direction of current through gradient
coil
✔✔Why does the system default the phase encoding axis along the shortest axis of
anatomy - ✔✔To reduce aliaising
✔✔Compensatory gradients? - ✔✔All gradients produce a change of frequency and a
change of phase. Phase change is required for phase encoding but NOT wanted for
frequency or slice select, therefore extra compensatory gradients are applied to
rephrase the spins so there is no net phase change
✔✔Dead time - ✔✔Time the system is attending to all other slices in the stack after
exciting the first slice
✔✔Perfusion imaging - ✔✔used in conjunction with diffusion imaging, also relies on fast
scanning techniques and the rapid infusion of an intravenous contrast agent
(gadolinium) to visualize the transit time of blood through a specific area. GRE
✔✔Diffusion Tensor Imaging (DTI) - ✔✔a technique used to produce images of the
brain that shows connections among different regions. Measured along three orthogonal
directions. Used for napping white matter Tracts as functional anisotropy maps or
tractography images (the weird images with colours)
✔✔Fomite - ✔✔Any inanimate object to which infectious material adheres and can be
transmitted.
✔✔A narrow receive bandwidth does what to susceptibility artifact - ✔✔Increased
susceptibility artifact
✔✔What orientation best sees tear of collateral ligaments of knee - ✔✔Coronal
✔✔Best plane to see tfcc tears = - ✔✔Coronal
✔✔Hemangioma in liver are best visualized in what phase after contrast injection -
✔✔Delayed images
✔✔Reducing flip angle causes what change in image contrast - ✔✔Less T1 information
, ✔✔Permanent magnets with a vertical magnetic field use surface coils that are -
✔✔Solenoids.the secondary magnetic field B1 created by RG coil must be
perpendicular to the orientation of B0
✔✔A STIR with a T1 of 160ms will null signal from fat at what field strength - ✔✔The T1
of fat at 1.5 Tesla is 240 with a bull point of 160ms
✔✔What elements are ferromagnetic - ✔✔iron, nickel, cobalt, gadolinium
✔✔What is a solenoid electromagnet - ✔✔Magnets that use current passed through the
coils of a wire to generate a magnetic field. Used in closed bore systems
✔✔Active shielding - ✔✔uses additional superconducting coils located at each end of
the main magnet inside the cryostat to shield the system. Bucking coils. Solenoids that
carry current in the opposite direction to reverse the flux.
✔✔Innermost part of the scanner - ✔✔Radio frequency coils - gradient coils - shim coils
- main magnet
✔✔Active shimming - ✔✔____________ is a term used to describe the adjustment of
the current within the shim coils on a per patient or per sequence basis. Uses
electromagnets instead of ferromagnetic shims (as in passive shimming).
✔✔Vertebral body will have __ signal on T1 in presence of fracture infection or
neoplasm - ✔✔Hypointense
✔✔Doubling field strength will do what to snr, and to SAR - ✔✔Double it ; quadruple it.
SAR is proportional to the power of 2 for the resonant frequency
✔✔Sequence best for cardiac imaging? - ✔✔EPI; due to its capability of acquiring
imaging in a fraction of a second
✔✔Two main flow phenomena - ✔✔ESP: hyperintense vessel because inflowing nuclei
do not receive repeated reseated RF pulses
ToF: signal loss
✔✔2D imaging - ✔✔Most common mri acquisition. Fills one line of k space in each slice
before moving on to the next one of k space
✔✔Ways to reduce patient heating - ✔✔Remove sat pulses, increaseTR, decrease slice
number, use appropriate receive coil, avoid trains of 180 pulses, reduce flip angle of
rephasing pulses
