mri arrt mock exam 100 questions

A patient is positioned inside a 3.0 T MRI scanner. Which statement best explains why a net magnetization vector (NMV) is produced?

A. All hydrogen nuclei align parallel to B₀.

B. RF energy forces hydrogen nuclei into the parallel state.

C. A slight excess of hydrogen nuclei occupy the low-energy parallel state.

D. Hydrogen nuclei stop precessing after entering the magnetic field.

C. A slight excess of hydrogen nuclei occupy the low-energy parallel state.

The Larmor equation describes the relationship between:

A. Gradient strength and scan time

B. Magnetic field strength and precessional frequency

C. RF pulse duration and flip angle

D. Echo time and repetition time

B. Magnetic field strength and precessional frequency

A hydrogen proton absorbs RF energy only when:

A. The RF pulse is applied at the Larmor frequency.

B. The RF pulse has a 180° flip angle.

C. The gradient coils are active.

D. The proton has completed one full precession.

A. The RF pulse is applied at the Larmor Frequency

Immediately after a 90° RF pulse, the longitudinal magnetization is:

A. At its maximum

B. Approximately zero

C. Greater than the transverse magnetization

D. Unchanged from equilibrium

C. Greater than the transverse magnetization

Which event occurs during T1 relaxation?

A. Loss of transverse phase coherence

B. Recovery of longitudinal magnetization through energy transfer to the lattice

C. Reversal of gradient polarity

D. Formation of the echo signal

C. Reversal of gradient polarity

T2 relaxation primarily results from:

A. RF absorption

B. Energy transfer to surrounding molecules

C. Loss of phase coherence between neighboring spins

D. Gradient-induced dephasing only

B. Energy transfer to surrounding molecules

Which tissue has the shortest T1 relaxation time?

A. CSF

B. Cortical bone

C. Fat

D. Air

C. Fat

Which tissue typically has the longest T2 relaxation time?

A. Fat

B. White matter

C. Water (CSF)

D. Muscle

C. Water (CSF)

Why does water appear bright on T2-weighted images?

A. It has rapid T1 recovery.

B. It retains transverse magnetization longer.

C. It has the highest gyromagnetic ratio.

D. It has the lowest proton density.

B. It retains transverse magnetization longer.

A Spin Echo sequence uses a 180° RF pulse primarily to:

A. Increase T1 recovery

B. Correct dephasing caused by magnetic field inhomogeneity

C. Eliminate longitudinal magnetization

D. Increase SAR

B. Correct dephasing caused by magnetic field inhomogeneity

Which sequence is most sensitive to magnetic susceptibility?

A. Spin Echo

B. Fast Spin Echo

C. Gradient Echo

D. STIR

C. Gradient Echo

The gyromagnetic ratio (γ) is:

A. Different for every MRI scanner.

B. A constant unique to each nucleus.

C. Equal to the magnetic field strength.

D. Determined by TR.

B. A constant unique to each nucleus

Increasing the magnetic field strength from 1.5 T to 3.0 T will generally:

A. Decrease SNR

B. Increase SNR

C. Eliminate chemical shift

D. Shorten scan time automatically

B. Increase SNR

Which of the following best describes resonance?

A. Alignment of protons with the magnetic field

B. Synchronization of gradient coils

C. Absorption of RF energy at the Larmor frequency

D. Recovery of longitudinal magnetization

C. Absorption of RF energy at the Larmor frequency

Which component of the MRI system produces the main magnetic field?

A. Gradient coils

B. RF coil

C. Main magnet

D. Shim coils

C. Main magnet

The purpose of shimming is to:

A. Increase slice thickness

B. Improve magnetic field homogeneity

C. Increase RF power

D. Reduce scan time

B. improve magnetic field homogeneity

A superconducting MRI magnet maintains its magnetic field by:

A. Permanent magnets only

B. Electrical resistance

C. Zero electrical resistance at cryogenic temperatures

D. Alternating current through the gradient coils

C. Zero electrical resistance at cryogenic temperatures

Liquid helium is used primarily to:

A. Cool the gradient coils

B. Reduce RF interference

C. Maintain superconductivity

D. Increase the magnetic field strength

C. Maintain superconductivity

What is the primary purpose of the RF receive coil?

A. Generate B₀

B. Produce gradients

C. Detect the MR signal emitted by precessing protons

D. Suppress fat signal

C. Detect the MR signal emitted by precessing protons

Which statement best describes the relationship between T1 and T2 relaxation?

A. T1 and T2 occur one after the other.

B. T2 begins only after T1 recovery is complete.

C. T1 recovery and T2 decay begin simultaneously after the RF pulse ends.

D. T1 occurs only in Gradient Echo sequences.

C. T1 recovery and T2 decay begin simultaneously after the RF pulse ends.

A technologist is selecting parameters for a T1-weighted spin echo brain sequence. Which combination will produce the strongest T1 weighting?

A. Long TR and long TE
B. Short TR and short TE
C. Long TR and short TE
D. Short TR and long TE

B. Short TR and short TE

A T2-weighted fast spin echo sequence is being performed. Which parameter combination is most appropriate?

A. Short TR, short TE
B. Short TR, long TE
C. Long TR, long TE
D. Long TR, short TE

C. Long TR, long TE

The primary purpose of the 180° refocusing pulse in a spin echo sequence is to:

A. Create longitudinal magnetization
B. Correct for dephasing caused by field inhomogeneities
C. Increase proton density
D. Reduce T1 relaxation

B. Correct for dephasing caused by field inhomogeneities

Which MRI sequence is best for detecting acute ischemic stroke?

A. T1-weighted spin echo
B. T2-weighted fast spin echo
C. Diffusion-weighted imaging (DWI)
D. Proton density imaging

C. Diffusion-weighted imaging (DWI)

A radiologist wants a sequence that suppresses CSF signal to better visualize periventricular lesions. Which sequence should be used?

A. STIR
B. FLAIR
C. GRE
D. T1 FSE

B. FLAIR

STIR suppresses fat because:

A. Fat has a short T2 relaxation time
B. Fat is saturated by increasing bandwidth
C. Fat is nulled when its longitudinal magnetization crosses zero
D. Fat has no hydrogen atoms

C. Fat is nulled when its longitudinal magnetization crosses zero

Why should STIR not be used after gadolinium administration?

A. STIR increases SAR too much
B. Gadolinium enhancement may be suppressed along with fat
C. STIR cannot produce T1 contrast
D. Gadolinium causes chemical shift artifact

B. Gadolinium enhancement may suppressed along with fat

Which sequence is most commonly used for detecting hemorrhage due to susceptibility effects?

A. Gradient Echo
B. STIR
C. FLAIR
D. Proton Density

A. Gradient Echo

Compared with spin echo imaging, gradient echo sequences:

A. Use a 180° refocusing pulse
B. Are less sensitive to susceptibility
C. Use gradient reversal to form echoes
D. Require longer scan times

C. Use gradient reversal to form echoes

The flip angle in a gradient echo sequence primarily affects:

A. Image contrast and signal intensity
B. Magnetic field strength
C. Patient positioning
D. Slice location only

A. Image contrast and signal intensity

A balanced SSFP sequence is commonly used because it provides:

A. Very low signal intensity
B. Excellent fluid contrast and rapid acquisition
C. Complete elimination of artifacts
D. Fat suppression without preparation pulses

B. Excellent fluid contrast and rapid acquisition

Echo Train Length (ETL) in Fast Spin Echo refers to:

A. The number of slices acquired per scan
B. The number of echoes collected after one excitation
C. The time between RF pulses
D. The number of RF coils used

B. The number of echoes collected after one excitation

Increasing ETL in Fast Spin Echo will generally:

A. Increase scan time
B. Reduce scan efficiency
C. Decrease scan time but may increase blurring
D. Eliminate T2 decay

C. Decrease scan time but may increase blurring

Which sequence is commonly used for rapid imaging because it collects many lines of k-space after one excitation?

A. Spin Echo
B. Echo Planar Imaging (EPI)
C. STIR
D. Proton Density

B. Echo Planar Imaging (EPI)

Diffusion-weighted imaging primarily measures:

A. Blood flow velocity
B. Proton density
C. Movement of water molecules
D. T1 recovery time

C. Movement of water molecules

A patient has an MRI of the knee. The physician wants excellent visualization of cartilage and fluid. Which sequence is commonly useful?

A. Proton density with fat suppression
B. T1-weighted imaging only
C. GRE without fat suppression
D. FLAIR

A. Proton density with fat suppression

The inversion time (TI) in an inversion recovery sequence determines:

A. Echo formation time
B. Which tissue is nulled
C. Magnetic field strength
D. Gradient amplitude

B. Which tissue is nulled.

A technologist wants to suppress fat while maintaining high-resolution imaging of a small joint. Which technique is preferred?

A. STIR
B. Frequency-selective fat saturation
C. Increasing TE only
D. Increasing TR only

B. Frequency-selective fat saturation

Which statement about proton density (PD) weighting is correct?

A. It emphasizes differences in T1 recovery
B. It emphasizes differences in T2 decay
C. It uses long TR and short TE to minimize T1 and T2 effects
D. It requires short TR and long TE

C. It uses long TR and short TE to minimize T1 and T2 effects

A T2-weighted image is acquired with a very long TE. What effect will occur?

A. Increased T1 weighting
B. More T2 contrast but decreased signal
C. Increased fat signal
D. Elimination of T2 decay

B. More T2 contrast but decreased signal

A technologist wants to increase T1 weighting on a spin echo sequence. Which adjustment is most appropriate?

A. Increase TR
B. Increase TE
C. Decrease TR
D. Decrease flip angle

C. Decrease TR

A technologist increases TE while keeping all other parameters unchanged. What is the expected result?

A. Increased T1 weighting
B. Increased T2 weighting and decreased signal
C. Increased SNR
D. Decreased T2 weighting

B. Increased T2 weighting and decreased signal

A technologist increases TR from 500 ms to 2500 ms. Which change is expected?

A. Increased T1 contrast
B. Decreased T1 weighting
C. Increased chemical shift artifact
D. Decreased scan time

B. Decreased T1 weighting

A technologist wants to improve spatial resolution while maintaining the same field of view. Which adjustment should be made?

A. Decrease matrix size
B. Increase matrix size
C. Increase slice thickness
D. Increase NEX only

B. Increase matrix size

Increasing the matrix size while maintaining the same FOV will:

A. Increase pixel size
B. Decrease spatial resolution
C. Decrease pixel size
D. Increase SNR

C. Decrease pixel size

A decrease in voxel size will generally result in:

A. Increased SNR
B. Decreased spatial resolution
C. Decreased SNR
D. Increased partial volume averaging

C. Decreased SNR

A technologist increases slice thickness from 3 mm to 6 mm. What is the expected effect?

A. Increased SNR and decreased resolution
B. Decreased SNR and increased resolution
C. Increased chemical shift
D. Increased scan time

A. Increased SNR and decreased resolution

The primary advantage of increasing NEX/NSA is:

A. Reduced scan time
B. Increased SNR
C. Improved fat suppression
D. Increased spatial resolution

B. Increased SNR

If NEX is increased from 2 to 4, the SNR will approximately:

A. Double
B. Increase by √2
C. Increase by √4
D. Remain unchanged

C. Increase by √4

A technologist needs to reduce scan time. Which change would be most effective?

A. Increase NEX
B. Increase matrix size
C. Decrease NEX
D. Decrease bandwidth

C. Decrease NEX

Increasing receiver bandwidth will generally:

A. Increase SNR and increase chemical shift
B. Decrease chemical shift but decrease SNR
C. Increase SNR and reduce artifacts
D. Increase scan time

B. Decrease chemical shift but decrease SNR

Chemical shift artifact occurs because:

A. Hydrogen nuclei stop precessing
B. Fat and water have different resonance frequencies
C. The patient moves during scanning
D. The matrix is too large

B. Fat and water have different resonance frequencies

A small FOV is selected for a wrist MRI. What is the expected effect?

A. Larger pixels and increased SNR
B. Smaller pixels and improved spatial resolution
C. Reduced resolution and increased scan time
D. Elimination of aliasing

B. Smaller pixels and improved spatial resolution

Wrap-around artifact occurs when:

A. The TE is too short
B. The FOV is too small for the anatomy being imaged
C. The slice thickness is too large
D. The bandwidth is too high

B. The FOV is too small for the anatomy being imaged

Which part of k-space primarily determines image contrast and overall signal?

A. Outer portion
B. Center portion
C. Corners only
D. Frequency encoding direction only

B. Center portion

The outer regions of k-space primarily contribute to:

A. Contrast information
B. Spatial resolution and fine detail
C. T1 recovery
D. RF excitation

B. Spatial resolution and fine detail

A motion artifact appears as repeated anatomy across the phase direction. The best first adjustment is usually:

A. Increase TE
B. Increase motion control or reduce scan time
C. Decrease bandwidth
D. Increase slice thickness only

B. Increase motion control or reduce scan time

In conventional spin echo imaging, scan time is calculated by:

A. TR × frequency matrix × TE
B. TR × phase matrix × NEX
C. TE × slice thickness × FOV
D. TR × bandwidth × matrix

B. TR × phase matrix × NEX

A Fast Spin Echo sequence has an ETL of 8. Compared with conventional Spin Echo, the scan time is reduced because:

A. Eight slices are automatically thicker
B. Eight echoes are collected per TR
C. TE is eliminated
D. T2 decay does not occur

B. Eight echoes are collected per TR

A patient’s MRI image shows ghosting in the phase-encoding direction. The most likely cause is:

A. Chemical shift
B. Patient motion
C. Incorrect slice thickness
D. Magnetic susceptibility

B. Patient motion

A technologist notices anatomy from outside the field of view appearing on the opposite side of the image. This artifact is:

A. Zipper artifact
B. Aliasing (wrap-around) artifact
C. Gibbs artifact
D. Magic angle artifact

B. Aliasing (wrap-around) artifact

The best way to reduce wrap-around artifact is to:

A. Decrease bandwidth
B. Increase FOV or use phase oversampling
C. Increase TE
D. Reduce matrix size

B. Increase FOV or use phase oversampling

A bright and dark band appears at the interface between fat and water. This is most likely:

A. Motion artifact
B. Chemical shift artifact
C. Flow artifact
D. Truncation artifact

B. Chemical shift artifact

Which adjustment will reduce chemical shift artifact?

A. Increase receiver bandwidth
B. Decrease receiver bandwidth
C. Increase TE
D. Increase slice thickness

A. Increase receiver bandwidth

A patient with a hip prosthesis demonstrates severe image distortion. The primary cause is:

A. Aliasing
B. Susceptibility artifact
C. Chemical shift
D. Gibbs artifact

B. Susceptibility artifact

Which technique is most effective for reducing susceptibility artifact from metal?

A. Gradient echo imaging
B. Increasing TE
C. Spin echo or fast spin echo techniques
D. Lowering bandwidth

C. Spin echo or fast spin echo techniques

A stair-step appearance near a sharp boundary is seen due to insufficient sampling. This artifact is:

A. Gibbs (truncation) artifact
B. Motion artifact
C. Zipper artifact
D. Cross-talk artifact

A. Gibbs (truncation) artifact

Gibbs artifact can be reduced by:

A. Decreasing matrix size
B. Increasing matrix size
C. Increasing TE
D. Decreasing bandwidth

B. Increasing matrix size

A zipper artifact is most commonly caused by:

A. Patient movement
B. RF interference entering the MRI system
C. Incorrect gradient amplitude
D. Poor shimming only

B. RF interference entering the MRI system

The static magnetic field of an MRI scanner is:

A. Only active during scanning
B. Always present in a superconducting magnet
C. Turned off between patients
D. Created by RF coils

B. Always present in a superconducting magnet

The greatest danger of a ferromagnetic object entering the MRI room is:

A. Chemical shift
B. Projectile effect
C. Increased SNR
D. Reduced SAR

B. Projectile effect

MRI safety screening is primarily designed to identify:

A. Patients who need shorter scan times
B. Ferromagnetic objects and unsafe implants
C. Patients with low proton density
D. Patients with poor image quality

B. Ferromagnetic objects and unsafe implants

SAR is a measurement of:

A. Gradient switching speed
B. RF energy absorbed by the patient
C. Magnetic field homogeneity
D. Image resolution

B. RF energy absorbed by the patient

Increasing flip angle in a pulse sequence generally:

A. Decreases SAR
B. Increases SAR
C. Eliminates T2 decay
D. Reduces magnetic field strength

B. Increases SAR

Peripheral nerve stimulation (PNS) is primarily caused by:

A. Static magnetic field
B. Time-varying gradient fields
C. RF coils only
D. Cryogen evaporation

B. Time-varying gradient fields

The purpose of MRI zones is to:

A. Improve image contrast
B. Control access and maintain safety
C. Increase magnet strength
D. Reduce scan time

B. Control access and maintain safety

Gadolinium contrast primarily improves MRI by:

A. Increasing T2 relaxation time
B. Shortening T1 relaxation time
C. Increasing proton density
D. Eliminating susceptibility effects

B. Shortening T1 relaxation time

A major concern when administering gadolinium to patients with severe renal impairment is:

A. Aliasing artifact
B. Nephrogenic systemic fibrosis (NSF)
C. Increased SAR
D. RF burns

B. Nephrogenic systemic fibrosis (NSF)

A patient reports a previous allergic reaction to gadolinium. The technologist should first:

A. Ignore the history because reactions are rare
B. Notify the appropriate healthcare provider and follow facility protocol
C. Increase the contrast dose
D. Proceed without documentation

B. Notify the appropriate healthcare provider and follow facility protocol

On an axial brain MRI, the structure that connects the two cerebral hemispheres is:

A. Corpus callosum
B. Thalamus
C. Pons
D. Caudate nucleus

A. Corpus callosum

The cerebrospinal fluid (CSF)-filled spaces within the brain are called:

A. Sulci
B. Ventricles
C. Gyri
D. Basal ganglia

B. Ventricles

The cerebellum is primarily responsible for:

A. Speech comprehension
B. Hormone regulation
C. Balance and coordination
D. Memory storage

C. Balance and coordination

A sagittal MRI image best demonstrates:

A. Left-to-right structures and midline anatomy
B. Anterior-to-posterior flow direction only
C. Cross-sectional vascular anatomy
D. Axial relationships between organs

A. Left-to-right structures and midline anatomy

The spinal cord is best evaluated using which imaging plane for overall cord length?

A. Axial
B. Sagittal
C. Coronal
D. Oblique only

B. Sagittal

A patient presents with suspected herniated lumbar disc. Which sequence is typically most useful for evaluating disc pathology?

A. T2-weighted imaging
B. T1-weighted imaging only
C. GRE only
D. FLAIR

A. T2-weighted imaging

On a T2-weighted spine image, cerebrospinal fluid usually appears:

A. Dark
B. Bright
C. The same intensity as bone
D. Absent

B. Bright

A meniscal tear in the knee is best visualized using:

A. T1-weighted imaging without fat suppression
B. Fluid-sensitive sequences such as PD fat-sat or T2 fat-sat
C. FLAIR
D. GRE only

B. Fluid-sensitive sequences such as PD fat-sat or T2 fat-sat

The rotator cuff is primarily evaluated during MRI of the:

A. Knee
B. Shoulder
C. Wrist
D. Ankle

B. Shoulder

A patient has a suspected ACL tear. Which structure is being evaluated?

A. Shoulder tendon
B. Knee ligament
C. Hip cartilage
D. Spinal disc

B. Knee ligament

Time-of-flight (TOF) MRA primarily depends on:

A. Fat suppression
B. Inflow of unsaturated blood into the imaging slice
C. Gadolinium only
D. T1 shortening from contrast

B. Inflow of unsaturated blood into the imaging slice

The entry-slice phenomenon occurs because:

A. Stationary tissue becomes brighter
B. Fresh spins entering the slice have not experienced previous RF pulses
C. Flow causes complete signal loss
D. Gradients eliminate blood signal

B. Fresh spins entering the slice have not experienced previous RF pulses

A saturation band placed above the imaging slice is used to:

A. Increase arterial signal
B. Suppress inflowing venous blood
C. Increase T2 contrast
D. Eliminate motion artifact

B. Suppress inflowing venous blood

Phase contrast MRA determines flow based on:

A. T1 recovery differences
B. Phase shifts caused by moving spins
C. Fat and water frequency differences
D. Proton density differences

B. Phase shifts caused by moving spins

Flow compensation is used to:

A. Reduce flow-related artifacts
B. Increase SAR
C. Suppress fat
D. Increase slice thickness

A. Reduce flow-related artifacts

Diffusion-weighted imaging (DWI) is especially useful for detecting:

A. Acute ischemic stroke
B. Chronic bone fractures
C. Tendon calcification
D. Fat suppression

A. Acute ischemic stroke

A patient with multiple sclerosis is commonly evaluated using:

A. FLAIR imaging
B. STIR only
C. T1 without contrast only
D. GRE only

A. FLAIR imaging

A tumor becomes brighter after gadolinium administration on a T1-weighted sequence because:

A. Gadolinium increases T2 relaxation time
B. Gadolinium shortens T1 relaxation time
C. Gadolinium removes hydrogen atoms
D. Gadolinium eliminates all artifacts

B. Gadolinium shortens T1 relaxation time

A patient cannot remain still during an MRI exam. Which adjustment may help reduce motion artifact?

A. Increase scan time
B. Use faster sequences and motion compensation techniques
C. Increase TE significantly
D. Decrease bandwidth

B. Use faster sequences and motion compensation techniques

A technologist is imaging the brain and wants to highlight edema and pathology. Which sequence combination is most appropriate?

A. T1-weighted imaging only
B. T2-weighted and FLAIR imaging
C. Proton density only
D. GRE only

B. T2-weighted and FLAIR imaging