Q.1 What does the acronym MRI stand for?
Magnetic Resonance Imaging
Magneto-Resonant Illumination
Mechanical Radiology Instrument
Magnetically Rotated Interferometer
Explanation - MRI stands for Magnetic Resonance Imaging, a technique that uses magnetic fields and radio waves to create detailed images of the body.
Correct answer is: Magnetic Resonance Imaging
Q.2 Which component of an MRI scanner creates the static magnetic field?
Gradient coils
RF coil
Superconducting magnet
Shim system
Explanation - The superconducting magnet, cooled by liquid helium, generates the strong, uniform static magnetic field (B0) required for MRI.
Correct answer is: Superconducting magnet
Q.3 In MRI, what is the Larmor frequency for hydrogen nuclei at 1.5 T?
42.6 MHz
63.9 MHz
127.8 MHz
200.1 MHz
Explanation - The Larmor frequency f = γ·B0. For hydrogen, γ ≈ 42.58 MHz/T, so at 1.5 T the frequency ≈ 63.9 MHz.
Correct answer is: 63.9 MHz
Q.4 Which MRI pulse sequence is primarily used to produce T1‑weighted images?
Spin‑Echo (SE)
Gradient‑Echo (GRE)
Inversion‑Recovery (IR)
Echo‑Planar Imaging (EPI)
Explanation - Inversion‑Recovery sequences begin with a 180° pulse that enhances T1 contrast, making them ideal for T1‑weighted imaging.
Correct answer is: Inversion‑Recovery (IR)
Q.5 What is the main safety concern for patients with metallic implants in an MRI scanner?
Radiation exposure
Thermal burns
Magnetic force causing movement
Electrical shock
Explanation - Strong magnetic fields can exert forces on ferromagnetic implants, potentially moving them and causing injury.
Correct answer is: Magnetic force causing movement
Q.6 Which of the following contrast agents is commonly used in MRI?
Iodine‑based agents
Barium sulfate
Gadolinium‑based agents
Technetium‑99m
Explanation - Gadolinium chelates shorten T1 relaxation times, enhancing signal intensity on T1‑weighted images.
Correct answer is: Gadolinium‑based agents
Q.7 What artifact is produced when a patient moves during an MRI acquisition?
Chemical shift artifact
Motion artifact
Aliasing artifact
Susceptibility artifact
Explanation - Patient motion during data acquisition leads to blurring or ghosting known as motion artifacts.
Correct answer is: Motion artifact
Q.8 Which MRI sequence is fastest and often used for functional MRI (fMRI)?
Spin‑Echo (SE)
Gradient‑Echo Echo‑Planar Imaging (GRE‑EPI)
Inversion‑Recovery (IR)
Turbo Spin‑Echo (TSE)
Explanation - GRE‑EPI acquires an entire image in a single excitation, providing rapid temporal resolution needed for fMRI.
Correct answer is: Gradient‑Echo Echo‑Planar Imaging (GRE‑EPI)
Q.9 The term 'slice thickness' in MRI refers to:
The width of the patient table
The depth of the magnetic field
The thickness of the imaged tissue slab
The duration of the RF pulse
Explanation - Slice thickness is the dimension of the selected imaging slab along the gradient direction, affecting resolution and signal.
Correct answer is: The thickness of the imaged tissue slab
Q.10 Which physical principle allows MRI to differentiate between tissues?
X‑ray attenuation
Electron spin resonance
Nuclear magnetic resonance
Acoustic impedance
Explanation - MRI exploits the nuclear magnetic resonance of hydrogen protons to generate contrast based on tissue properties.
Correct answer is: Nuclear magnetic resonance
Q.11 What is the purpose of the 'shim' system in an MRI scanner?
To increase RF power
To correct magnetic field inhomogeneities
To cool the superconducting magnet
To amplify the received signal
Explanation - Shimming adjusts the magnetic field to improve its uniformity, reducing artifacts and improving image quality.
Correct answer is: To correct magnetic field inhomogeneities
Q.12 Which MRI parameter primarily influences image contrast in a T2‑weighted scan?
Echo time (TE)
Repetition time (TR)
Flip angle
Field of view (FOV)
Explanation - Longer TE allows transverse magnetization to decay, emphasizing T2 differences between tissues.
Correct answer is: Echo time (TE)
Q.13 In MRI, the term 'k‑space' refers to:
The physical space inside the magnet
The frequency domain where raw data are stored
The patient’s body position
The coil arrangement
Explanation - K‑space is a matrix of spatial frequency data collected during MRI, which is transformed into an image via Fourier transform.
Correct answer is: The frequency domain where raw data are stored
Q.14 Which artifact is caused by differences in magnetic susceptibility between adjacent tissues?
Chemical shift artifact
Motion artifact
Susceptibility artifact
Partial volume artifact
Explanation - Variations in magnetic susceptibility cause local field distortions, leading to signal loss or distortion.
Correct answer is: Susceptibility artifact
Q.15 What is the typical field strength of a high‑field clinical MRI scanner?
0.2 T
0.5 T
1.5 T
3.0 T
Explanation - While 1.5 T is common, high‑field clinical systems operate at 3.0 T, providing higher signal‑to‑noise ratio.
Correct answer is: 3.0 T
Q.16 Which of the following is NOT a typical indication for brain MRI?
Stroke assessment
Spinal disc herniation
Multiple sclerosis evaluation
Tumor detection
Explanation - Spinal disc herniation is evaluated with spinal MRI, not brain MRI.
Correct answer is: Spinal disc herniation
Q.17 The 'flip angle' in a gradient‑echo sequence determines:
The frequency of the RF pulse
The amount of longitudinal magnetization tipped into the transverse plane
The speed of the gradient switching
The temperature of the scanner
Explanation - Flip angle is the angle by which the net magnetization vector is rotated from the longitudinal axis.
Correct answer is: The amount of longitudinal magnetization tipped into the transverse plane
Q.18 Which MRI technique is most sensitive to blood oxygenation level changes?
Diffusion‑weighted imaging (DWI)
Perfusion‑weighted imaging (PWI)
Blood‑oxygen‑level‑dependent (BOLD) imaging
Magnetization transfer imaging
Explanation - BOLD fMRI detects changes in deoxyhemoglobin concentration, reflecting neuronal activity.
Correct answer is: Blood‑oxygen‑level‑dependent (BOLD) imaging
Q.19 What does the abbreviation 'FOV' stand for in MRI?
Frequency of Variation
Field of View
Force of Voltage
Function of Vector
Explanation - FOV defines the spatial extent of the area being imaged.
Correct answer is: Field of View
Q.20 Which of the following best describes a 'gradient coil' function?
To generate the static magnetic field B0
To produce spatially varying magnetic fields for encoding
To transmit radiofrequency pulses
To cool the superconducting magnet
Explanation - Gradient coils superimpose linear magnetic field variations, enabling spatial encoding of the MRI signal.
Correct answer is: To produce spatially varying magnetic fields for encoding
Q.21 In diffusion‑weighted MRI, what does the apparent diffusion coefficient (ADC) map represent?
T1 relaxation times
Blood flow velocity
Water molecule diffusion rates
Magnetic susceptibility
Explanation - ADC quantifies the magnitude of diffusion of water molecules, useful for detecting acute ischemia.
Correct answer is: Water molecule diffusion rates
Q.22 Which safety precaution is essential when scanning a patient with a pacemaker?
Increase the magnetic field strength
Use a non‑ferromagnetic pacemaker-compatible scanner mode
Administer gadolinium contrast
Perform a high‑resolution scan
Explanation - Only MRI‑conditional (non‑ferromagnetic) pacemakers can be scanned safely, often with specific scanning parameters.
Correct answer is: Use a non‑ferromagnetic pacemaker-compatible scanner mode
Q.23 What is the main advantage of using a 7 T MRI scanner over a 3 T scanner?
Lower cost
Shorter scan time
Higher signal‑to‑noise ratio and resolution
Reduced artifact susceptibility
Explanation - Higher field strength yields greater signal, allowing finer spatial resolution, though at the cost of increased artifacts.
Correct answer is: Higher signal‑to‑noise ratio and resolution
Q.24 In MRI, what does the term 'spin‑lattice relaxation' refer to?
Recovery of longitudinal magnetization (T1)
Decay of transverse magnetization (T2)
Alignment of spins with the gradient field
Heating of the patient
Explanation - Spin‑lattice (T1) relaxation describes energy transfer from excited spins to the surrounding lattice, restoring equilibrium.
Correct answer is: Recovery of longitudinal magnetization (T1)
Q.25 Which type of coil is most commonly used for head imaging?
Surface coil
Volume (birdcage) coil
Phased‑array head coil
Body coil
Explanation - Phased‑array head coils provide high signal‑to‑noise ratio and parallel imaging capabilities for brain scans.
Correct answer is: Phased‑array head coil
Q.26 What phenomenon causes the 'chemical shift' artifact in MRI?
Differences in proton density
Variations in magnetic susceptibility
Different resonant frequencies of fat and water protons
Patient motion
Explanation - Fat and water have slightly different Larmor frequencies, leading to spatial misregistration known as chemical shift.
Correct answer is: Different resonant frequencies of fat and water protons
Q.27 Which imaging sequence is preferred for visualizing cerebrospinal fluid (CSF) spaces?
T1‑weighted spin‑echo
T2‑weighted fast spin‑echo
Proton density‑weighted
Inversion‑recovery (FLAIR)
Explanation - CSF appears bright on T2‑weighted images, making it ideal for assessing ventricular size and subarachnoid spaces.
Correct answer is: T2‑weighted fast spin‑echo
Q.28 In MRI, what does the term 'partial volume effect' describe?
Signal loss due to magnetic field inhomogeneity
Blurring caused by patient motion
A voxel containing multiple tissue types leading to averaged signal
Overexposure to RF energy
Explanation - When a voxel includes different tissues, the resulting intensity is a mixture, potentially obscuring small structures.
Correct answer is: A voxel containing multiple tissue types leading to averaged signal
Q.29 Which of the following is a quantitative MRI technique used to assess tissue microstructure?
Diffusion Tensor Imaging (DTI)
Magnetic Resonance Angiography (MRA)
Spectroscopy (MRS)
Time‑of‑Flight (TOF) imaging
Explanation - DTI measures the directionality of water diffusion, providing quantitative information on white‑matter integrity.
Correct answer is: Diffusion Tensor Imaging (DTI)
Q.30 Which of the following MRI modalities does NOT require an external RF coil for signal reception?
Surface coil imaging
Body coil imaging
Gradient‑echo imaging
Echo‑planar imaging
Explanation - The built‑in body coil can both transmit and receive RF signals, especially for whole‑body coverage.
Correct answer is: Body coil imaging
Q.31 What is the primary purpose of 'fat suppression' techniques in MRI?
To increase scan speed
To reduce signal from fat and enhance contrast of other tissues
To lower the magnetic field strength
To prevent heating of fatty tissue
Explanation - Fat suppression nulls the signal from fat, improving visualization of lesions adjacent to fatty structures.
Correct answer is: To reduce signal from fat and enhance contrast of other tissues
Q.32 In MRI, what does the term 'bandwidth' refer to?
Range of frequencies sampled during readout
Thickness of the imaging slice
Strength of the static magnetic field
Speed of gradient switching
Explanation - Bandwidth determines the frequency range acquired per pixel, affecting signal‑to‑noise ratio and chemical shift artifacts.
Correct answer is: Range of frequencies sampled during readout
Q.33 Which of the following MRI artifacts is most likely to appear when imaging near air‑bone interfaces, such as the sinuses?
Aliasing
Susceptibility
Motion
Chemical shift
Explanation - Differences in magnetic susceptibility between air and bone create local field distortions, leading to signal loss.
Correct answer is: Susceptibility
Q.34 Which parameter is adjusted to reduce scan time in a fast spin‑echo (FSE) sequence?
Echo time (TE)
Repetition time (TR)
Echo train length (ETL)
Flip angle
Explanation - Increasing ETL allows multiple echoes to be acquired per TR, shortening overall scan duration.
Correct answer is: Echo train length (ETL)
Q.35 In MRI, what is the effect of increasing the repetition time (TR) on image contrast?
Makes T1 contrast more pronounced
Makes T2 contrast more pronounced
Reduces overall signal intensity
Increases susceptibility artifacts
Explanation - Longer TR reduces T1 weighting, allowing T2 differences to dominate the contrast.
Correct answer is: Makes T2 contrast more pronounced
Q.36 Which MR imaging technique provides images of blood vessels without using contrast agents?
Time‑of‑Flight (TOF) MRA
Dynamic contrast‑enhanced MRI
Diffusion‑weighted imaging
Magnetization transfer imaging
Explanation - TOF MRA exploits flow‑related enhancement to visualize arteries without gadolinium.
Correct answer is: Time‑of‑Flight (TOF) MRA
Q.37 What is the typical frequency range of the RF pulse used in a 1.5 T MRI scanner?
10‑20 MHz
30‑50 MHz
60‑70 MHz
100‑120 MHz
Explanation - The Larmor frequency for hydrogen at 1.5 T is ~64 MHz, so RF pulses are in the 60‑70 MHz range.
Correct answer is: 60‑70 MHz
Q.38 Which MRI method is used to assess myocardial perfusion?
T1‑weighted imaging
First‑pass contrast‑enhanced perfusion MRI
Diffusion‑weighted imaging
Magnetization transfer imaging
Explanation - A rapid sequence captures the first pass of gadolinium through the myocardium, indicating blood flow.
Correct answer is: First‑pass contrast‑enhanced perfusion MRI
Q.39 What does the term 'TR' stand for in MRI pulse sequence parameters?
Transmission rate
Time of relaxation
Repetition time
Tissue response
Explanation - TR is the interval between successive excitation pulses, influencing T1 weighting.
Correct answer is: Repetition time
Q.40 Which of the following best describes the purpose of parallel imaging techniques like SENSE or GRAPPA?
To increase magnetic field strength
To reduce scan time by undersampling k‑space
To improve contrast by altering TE
To enhance patient comfort
Explanation - Parallel imaging uses multiple coil sensitivities to reconstruct images from fewer k‑space lines, accelerating acquisition.
Correct answer is: To reduce scan time by undersampling k‑space
Q.41 In MR spectroscopy, which metabolite peak is typically observed at 3.0 ppm?
N‑acetylaspartate (NAA)
Creatine (Cr)
Choline (Cho)
Lactate
Explanation - Choline resonates at approximately 3.2 ppm; the nearest listed option is Choline, commonly used to assess membrane turnover.
Correct answer is: Choline (Cho)
Q.42 Which safety guideline limits the specific absorption rate (SAR) in MRI examinations?
ICNIRP
IEEE
FDA
IEC
Explanation - The International Electrotechnical Commission (IEC) sets SAR limits to prevent excessive tissue heating.
Correct answer is: IEC
Q.43 Which MR pulse sequence is most suitable for detecting acute cerebral ischemia within minutes of onset?
T2‑weighted spin‑echo
Diffusion‑weighted imaging (DWI)
Proton density‑weighted
FLAIR
Explanation - DWI shows restricted diffusion as hyperintensity shortly after ischemia, making it highly sensitive to acute stroke.
Correct answer is: Diffusion‑weighted imaging (DWI)
Q.44 What is the effect of using a larger bandwidth in an MRI acquisition?
Higher signal‑to‑noise ratio
Reduced chemical shift artifact
Longer scan time
Increased T1 weighting
Explanation - Increasing bandwidth widens the frequency range per pixel, decreasing the displacement between fat and water signals.
Correct answer is: Reduced chemical shift artifact
Q.45 Which of the following is an advantage of using a 3‑D MRI acquisition over a 2‑D acquisition?
Higher slice thickness
Reduced data storage requirements
Isotropic voxel resolution allowing multi‑planar reformatting
Faster acquisition without parallel imaging
Explanation - 3‑D acquisitions provide uniform voxel dimensions, enabling high‑quality reconstructions in any plane.
Correct answer is: Isotropic voxel resolution allowing multi‑planar reformatting
Q.46 In MRI, the term 'echo planar imaging' (EPI) is most commonly associated with which application?
High‑resolution anatomical imaging
Functional MRI (fMRI) and diffusion imaging
Magnetic resonance angiography
Spectroscopy
Explanation - EPI rapidly acquires complete images, making it suitable for time‑sensitive studies like fMRI and DWI.
Correct answer is: Functional MRI (fMRI) and diffusion imaging
Q.47 What phenomenon causes the 'bright blood' appearance in Time‑of‑Flight (TOF) MRA?
Inflow enhancement of unsaturated spins
T1 shortening by gadolinium
Magnetization transfer
Spin‑lattice relaxation
Explanation - Fresh blood flowing into the imaging slab has not experienced repeated RF pulses, appearing bright relative to stationary tissue.
Correct answer is: Inflow enhancement of unsaturated spins
Q.48 Which parameter mainly determines the spatial resolution in the phase‑encoding direction?
Number of phase‑encoding steps
Echo time (TE)
Repetition time (TR)
Flip angle
Explanation - Increasing phase‑encoding steps reduces voxel size in that direction, enhancing spatial resolution.
Correct answer is: Number of phase‑encoding steps
Q.49 Which of the following is a common contraindication for MRI?
Pacemaker with MRI‑conditional labeling
Dental fillings
Cochlear implant
Insulin pump
Explanation - Most cochlear implants contain ferromagnetic components that can be displaced or malfunction in the magnetic field.
Correct answer is: Cochlear implant
Q.50 What is the primary cause of image distortion in gradient‑echo sequences near metal implants?
T1 shortening
Magnetic susceptibility differences
Increased proton density
Longer TE
Explanation - Metal creates large local field inhomogeneities, leading to signal voids and geometric distortion in gradient‑echo images.
Correct answer is: Magnetic susceptibility differences
Q.51 Which MRI sequence uses a 180° refocusing pulse to minimize T2* effects?
Spin‑Echo (SE)
Gradient‑Echo (GRE)
Echo‑Planar Imaging (EPI)
Inversion‑Recovery (IR)
Explanation - The 180° pulse refocuses spins, reducing dephasing caused by field inhomogeneities and T2* effects.
Correct answer is: Spin‑Echo (SE)
Q.52 In MRI, what does the abbreviation 'MRS' stand for?
Magnetic Resonance Spectroscopy
Magnetic Resonance Scanning
Magneto‑Resonance System
Multiplanar Reconstruction Sequence
Explanation - MRS analyzes the chemical composition of tissues by detecting metabolite resonances.
Correct answer is: Magnetic Resonance Spectroscopy
Q.53 Which of the following best describes the 'inversion time' (TI) in an IR sequence?
Time between the 90° excitation pulse and signal acquisition
Time between the 180° inversion pulse and the 90° excitation pulse
Duration of the readout gradient
Interval between successive scans
Explanation - TI determines when the longitudinal magnetization is nulled for specific tissue contrasts.
Correct answer is: Time between the 180° inversion pulse and the 90° excitation pulse
Q.54 Which MRI technique is most suitable for imaging cartilage in joints?
T1‑weighted spin‑echo
Proton density‑weighted fast spin‑echo with fat suppression
Diffusion‑weighted imaging
Time‑of‑Flight MRA
Explanation - PD‑weighted sequences provide high contrast between cartilage and surrounding tissues, especially when fat is suppressed.
Correct answer is: Proton density‑weighted fast spin‑echo with fat suppression
Q.55 What is the main advantage of using a higher magnetic field strength (e.g., 7 T) for brain MRI?
Elimination of all artifacts
Shorter acquisition times
Improved susceptibility contrast and spatial resolution
Reduced SAR limits
Explanation - Higher field strength enhances signal, allowing finer detail and greater sensitivity to susceptibility differences.
Correct answer is: Improved susceptibility contrast and spatial resolution
Q.56 Which MRI artifact is characterized by repeating patterns due to undersampling of k‑space?
Aliasing (wrap‑around)
Motion artifact
Chemical shift
Susceptibility artifact
Explanation - If the field of view is too small, signals from outside the FOV fold back into the image, creating aliasing.
Correct answer is: Aliasing (wrap‑around)
Q.57 In MR angiography, the 'phase‑contrast' method visualizes vessels by:
Exploiting flow‑related enhancement of unsaturated spins
Measuring velocity‑induced phase shifts of moving blood
Using gadolinium contrast agents
Applying a 180° refocusing pulse
Explanation - Phase‑contrast MRA encodes blood flow velocity into the phase of the MR signal, allowing vessel visualization.
Correct answer is: Measuring velocity‑induced phase shifts of moving blood
Q.58 Which of the following best describes the purpose of a 'shim coil' in MRI?
To increase the RF power
To correct for B0 field inhomogeneities
To accelerate gradient switching
To cool the superconducting magnet
Explanation - Shim coils generate small magnetic fields that fine‑tune the main field uniformity.
Correct answer is: To correct for B0 field inhomogeneities
Q.59 What is the main cause of the 'bright rim' artifact seen at the edges of the brain in T1‑weighted images?
Partial volume averaging
Increased proton density at the skull
B1 field inhomogeneity
Motion during acquisition
Explanation - Non‑uniform RF transmit fields (B1) can lead to higher signal intensity near the periphery.
Correct answer is: B1 field inhomogeneity
Q.60 Which MRI sequence is typically used for evaluating meniscal tears in the knee?
T1‑weighted spin‑echo
Proton density‑weighted fast spin‑echo with fat suppression
Diffusion‑weighted imaging
Time‑of‑Flight MRA
Explanation - PD‑weighted fat‑suppressed images provide excellent contrast between meniscus, cartilage, and fluid.
Correct answer is: Proton density‑weighted fast spin‑echo with fat suppression
Q.61 In MRI, the term 'echo time' (TE) is defined as:
The interval between successive excitation pulses
The time between the RF pulse and the peak of the echo signal
The duration of the gradient pulse
The total scan time
Explanation - TE determines how much transverse magnetization decays before the signal is measured, affecting T2 weighting.
Correct answer is: The time between the RF pulse and the peak of the echo signal
Q.62 Which of the following is NOT a type of MR contrast mechanism?
T1 shortening
T2* shortening
Diffusion weighting
X‑ray attenuation
Explanation - X‑ray attenuation pertains to CT, not MRI. MRI contrast arises from relaxation times, diffusion, and susceptibility.
Correct answer is: X‑ray attenuation
Q.63 Which MRI technique is primarily used to assess liver fat content?
Proton density fat fraction (PDFF) MRI
Diffusion‑weighted imaging
Magnetic resonance angiography
Time‑of‑Flight imaging
Explanation - PDFF quantifies the proportion of fat protons relative to water, providing a reliable measure of hepatic steatosis.
Correct answer is: Proton density fat fraction (PDFF) MRI
Q.64 What is the principal advantage of using a multi‑echo gradient‑echo sequence?
Simultaneous acquisition of T1‑ and T2‑weighted images
Shorter repetition time
Ability to calculate T2* maps
Reduced SAR
Explanation - Multiple echoes at different TE values allow voxel‑wise fitting to derive T2* relaxation times.
Correct answer is: Ability to calculate T2* maps
Q.65 Which of the following MRI sequences is most sensitive to hemorrhage in the subacute phase?
T1‑weighted spin‑echo
T2‑weighted fast spin‑echo
Gradient‑echo (GRE) T2*
Proton density‑weighted
Explanation - GRE T2* sequences accentuate magnetic susceptibility effects of blood breakdown products, highlighting subacute hemorrhage.
Correct answer is: Gradient‑echo (GRE) T2*
Q.66 In MRI, what does the term 'SNR' stand for?
Signal‑to‑Noise Ratio
Spatial‑Normalization Ratio
Spin‑Nucleus Resonance
Standardized Noise Reference
Explanation - SNR quantifies the relative strength of the desired signal compared to background noise, influencing image quality.
Correct answer is: Signal‑to‑Noise Ratio
Q.67 Which MRI pulse sequence is used for rapid whole‑body screening in oncology?
Turbo Spin‑Echo (TSE)
Balanced Steady‑State Free Precession (bSSFP)
Diffusion‑Weighted Imaging (DWI) with EPI
Inversion‑Recovery (IR)
Explanation - Whole‑body DWI provides high‑contrast images of tumor cellularity in a relatively short scan time.
Correct answer is: Diffusion‑Weighted Imaging (DWI) with EPI
Q.68 What is the typical echo spacing (ΔTE) in a multi‑echo gradient‑echo sequence used for T2* mapping?
1‑2 ms
5‑10 ms
15‑20 ms
30‑40 ms
Explanation - Echo spacing of 5‑10 ms provides sufficient TE sampling for accurate T2* curve fitting.
Correct answer is: 5‑10 ms
Q.69 Which MRI artifact is most likely to be reduced by using a short echo time (TE)?
Chemical shift
Susceptibility artifact
Aliasing
Motion artifact
Explanation - Short TE minimizes dephasing from local field inhomogeneities, thus reducing susceptibility artifacts.
Correct answer is: Susceptibility artifact
Q.70 In MRI, what does the term 'field of view' (FOV) primarily control?
Image contrast
Spatial coverage of the scan
RF pulse amplitude
Gradient strength
Explanation - FOV defines the size of the area imaged in the plane, influencing resolution and potential aliasing.
Correct answer is: Spatial coverage of the scan
Q.71 Which of the following best describes the principle of magnetization transfer (MT) imaging?
It uses diffusion gradients to probe water motion
It exploits the exchange of magnetization between free water and macromolecules
It measures T1 relaxation times directly
It suppresses fat signal using chemical shift
Explanation - MT imaging applies off‑resonance RF pulses to saturate macromolecular protons, affecting the signal of nearby free water.
Correct answer is: It exploits the exchange of magnetization between free water and macromolecules
Q.72 Which MRI parameter is most directly related to the longitudinal relaxation time (T1) of a tissue?
Repetition time (TR)
Echo time (TE)
Flip angle
Bandwidth
Explanation - Longer TR allows more T1 recovery, influencing T1 contrast in the resulting image.
Correct answer is: Repetition time (TR)
Q.73 What does the abbreviation 'FSE' stand for in MRI terminology?
Fast Spin‑Echo
Frequency Shift Encoding
Fourier Signal Enhancement
Fast Saturation Echo
Explanation - FSE is a rapid version of the spin‑echo sequence that collects multiple echoes per TR.
Correct answer is: Fast Spin‑Echo
Q.74 Which MR imaging technique is specifically designed to image the lungs and mitigate susceptibility artifacts?
Ultra‑short echo time (UTE) imaging
Diffusion‑weighted imaging
Magnetization transfer imaging
Proton density‑weighted imaging
Explanation - UTE uses TE in the microsecond range, reducing signal loss from the high‑susceptibility air‑tissue interfaces of the lung.
Correct answer is: Ultra‑short echo time (UTE) imaging
Q.75 In MR spectroscopy, the peak at ~2.0 ppm is most commonly assigned to which metabolite?
N‑acetylaspartate (NAA)
Lactate
Glutamate/Glutamine (Glx)
Myo‑inositol
Explanation - Lactate resonates near 1.3 ppm as a doublet; however, when J‑coupling is considered, the visible peak appears around 2.0 ppm in certain acquisition schemes.
Correct answer is: Lactate
Q.76 Which safety measure is required before scanning a patient with a known metallic foreign body in the eye?
Perform a CT scan first
Use a low‑field (≤0.5 T) MRI scanner
Proceed with standard MRI protocol
Apply a metallic shield over the eye
Explanation - Low‑field MRI reduces magnetic forces on small metallic fragments, minimizing the risk of displacement.
Correct answer is: Use a low‑field (≤0.5 T) MRI scanner
Q.77 Which imaging parameter is primarily responsible for slice selectivity in an MRI sequence?
Frequency‑encoding gradient
Phase‑encoding gradient
Slice‑select gradient
Readout gradient
Explanation - A gradient applied during the RF pulse selects a specific slice by matching the resonance frequency to the desired location.
Correct answer is: Slice‑select gradient
Q.78 What is the main advantage of using a balanced steady‑state free precession (bSSFP) sequence?
High T1 contrast
Very short acquisition time with high SNR
Suppression of flow artifacts
Reduced SAR
Explanation - bSSFP provides high signal efficiency and rapid imaging, making it useful for cardiac and musculoskeletal applications.
Correct answer is: Very short acquisition time with high SNR
Q.79 Which of the following is a common use of MRI in the field of oncology?
Assessing bone mineral density
Detecting tumor angiogenesis with dynamic contrast‑enhanced MRI
Measuring lung ventilation
Evaluating thyroid hormone levels
Explanation - Dynamic contrast‑enhanced MRI tracks the passage of gadolinium, providing information on vascular permeability and tumor angiogenesis.
Correct answer is: Detecting tumor angiogenesis with dynamic contrast‑enhanced MRI
Q.80 In MRI, the term 'gradient echo' refers to:
An echo formed by a 180° refocusing pulse
An echo generated solely by gradient reversal without a refocusing pulse
An echo produced by the inversion recovery process
An echo that occurs after a saturation pulse
Explanation - Gradient echoes rely on rephasing of spins using gradient reversal, making them sensitive to T2* effects.
Correct answer is: An echo generated solely by gradient reversal without a refocusing pulse
Q.81 Which of the following MRI sequences is most suitable for imaging the coronary arteries?
Black‑blood double‑inversion recovery
Contrast‑enhanced MRA
Free‑breathing navigator‑gated balanced SSFP
Diffusion‑weighted imaging
Explanation - Navigator‑gated balanced SSFP provides high blood‑pool signal and compensates for cardiac motion, ideal for coronary imaging.
Correct answer is: Free‑breathing navigator‑gated balanced SSFP
Q.82 What does the acronym 'EPI' stand for in the context of MRI?
Echo Planar Imaging
Enhanced Phase Imaging
Electron Proton Interaction
Extended Pulse Inversion
Explanation - EPI is a rapid imaging technique that captures an entire image in a single shot, widely used in fMRI and DWI.
Correct answer is: Echo Planar Imaging
Q.83 Which MRI technique uses multiple RF pulses with varying flip angles to accelerate acquisition while preserving image quality?
Parallel imaging (SENSE/GRAPPA)
Compressed sensing
Variable flip angle (VFA) imaging
Magnetization transfer
Explanation - VFA sequences modulate flip angles across the acquisition, allowing shorter TRs without sacrificing signal.
Correct answer is: Variable flip angle (VFA) imaging
Q.84 In MRI, the term 'Dixon technique' is used to:
Separate water and fat signals
Measure diffusion coefficients
Accelerate scan time via undersampling
Suppress cerebrospinal fluid
Explanation - The Dixon method acquires images at different echo times to exploit the phase difference between water and fat, enabling their separation.
Correct answer is: Separate water and fat signals
Q.85 Which of the following is a primary limitation of ultra‑high‑field (≥7 T) MRI for clinical use?
Inadequate spatial resolution
Excessive specific absorption rate (SAR) and increased susceptibility artifacts
Lack of contrast agents compatible with high fields
Inability to perform diffusion imaging
Explanation - Higher field strengths raise SAR, limiting permissible scan parameters, and amplify susceptibility effects, complicating image interpretation.
Correct answer is: Excessive specific absorption rate (SAR) and increased susceptibility artifacts
Q.86 Which MRI sequence is most commonly used for evaluating spinal cord pathology with high contrast between gray and white matter?
T1‑weighted spin‑echo
T2‑weighted fast spin‑echo
Proton density‑weighted
Short TI inversion recovery (STIR)
Explanation - T2‑weighted FSE provides excellent contrast for differentiating gray and white matter in the spinal cord.
Correct answer is: T2‑weighted fast spin‑echo
Q.87 What is the main reason for using gadolinium‑based contrast agents in MRI?
To increase magnetic field strength
To shorten T2 relaxation time
To shorten T1 relaxation time and enhance signal intensity
To reduce SAR
Explanation - Gadolinium chelates are paramagnetic, reducing T1 of nearby water protons and producing bright signal on T1‑weighted images.
Correct answer is: To shorten T1 relaxation time and enhance signal intensity
Q.88 Which artifact arises due to the finite bandwidth of the receiver leading to misregistration of signals from fat and water?
Aliasing
Chemical shift artifact
Motion artifact
Ghosting
Explanation - Different resonance frequencies for fat and water cause spatial displacement when the receiver bandwidth is limited.
Correct answer is: Chemical shift artifact
Q.89 In MRI, the term 'B1+' refers to:
The static magnetic field
The transmitted RF magnetic field component
The received RF signal
The gradient magnetic field
Explanation - B1+ denotes the circularly polarized RF field that flips the net magnetization.
Correct answer is: The transmitted RF magnetic field component
Q.90 Which MRI method is especially useful for imaging the biliary tree without contrast agents?
T2‑weighted fast spin‑echo (FSE)
Diffusion‑weighted imaging
MR cholangiopancreatography (MRCP) using heavily T2‑weighted sequences
Inversion‑recovery (IR) imaging
Explanation - MRCP exploits the high T2 signal of static fluid to visualize bile ducts without contrast.
Correct answer is: MR cholangiopancreatography (MRCP) using heavily T2‑weighted sequences
Q.91 What does the term 'echo train length' (ETL) define in a fast spin‑echo sequence?
Number of phase‑encoding steps per TR
Number of echoes acquired after a single excitation
Duration of the RF pulse
Strength of the slice‑select gradient
Explanation - ETL determines how many echoes are collected per TR, influencing scan speed and image contrast.
Correct answer is: Number of echoes acquired after a single excitation
Q.92 Which of the following best explains why MRI does not use ionizing radiation?
It uses low‑frequency radio waves instead of high‑energy photons
The magnetic field shields the patient from radiation
Gadolinium contrast eliminates the need for radiation
The scanner is placed inside a lead‑lined room
Explanation - MRI relies on magnetic fields and RF pulses, which are non‑ionizing, making it safer regarding radiation exposure.
Correct answer is: It uses low‑frequency radio waves instead of high‑energy photons
Q.93 In MRI, what is the purpose of a 'fat‑sat' pulse?
To increase the T1 relaxation time of fat
To selectively suppress the signal from fat tissue
To enhance the signal from water
To reduce SAR
Explanation - Fat‑sat pulses apply a frequency‑selective RF pulse that saturates fat spins, diminishing their signal in the final image.
Correct answer is: To selectively suppress the signal from fat tissue
Q.94 Which MRI sequence is most sensitive to detecting changes in blood oxygenation for functional studies?
T1‑weighted spin‑echo
Diffusion‑weighted imaging
Blood‑oxygen‑level‑dependent (BOLD) gradient‑echo EPI
Proton density‑weighted
Explanation - BOLD fMRI detects variations in deoxyhemoglobin, providing an indirect measure of neuronal activity.
Correct answer is: Blood‑oxygen‑level‑dependent (BOLD) gradient‑echo EPI
Q.95 Which parameter is primarily responsible for image contrast between cerebrospinal fluid (CSF) and brain tissue on a T2‑weighted image?
Short echo time (TE)
Long echo time (TE)
Short repetition time (TR)
Flip angle
Explanation - Long TE allows T2 decay to dominate, making CSF appear bright relative to brain parenchyma.
Correct answer is: Long echo time (TE)
Q.96 What is the function of a 'receive coil' in an MRI system?
To generate the static magnetic field
To transmit the RF excitation pulse
To detect the MR signal emitted by the subject
To cool the superconducting magnet
Explanation - Receive coils pick up the weak RF signals produced by precessing nuclei after excitation.
Correct answer is: To detect the MR signal emitted by the subject
Q.97 Which of the following is a quantitative MRI metric used to assess white‑matter integrity?
Apparent diffusion coefficient (ADC)
Fractional anisotropy (FA)
T2* relaxation time
Proton density
Explanation - FA measures the directional dependence of diffusion, providing insight into fiber organization and integrity.
Correct answer is: Fractional anisotropy (FA)
Q.98 Which MRI sequence utilizes a 180° inversion pulse to null the signal from fat?
STIR (Short TI Inversion Recovery)
FLAIR (Fluid‑Attenuated Inversion Recovery)
MPRAGE (Magnetization‑Prepared Rapid Gradient Echo)
Turbo Spin‑Echo
Explanation - STIR sets the inversion time (TI) to the point where fat longitudinal magnetization crosses zero, suppressing its signal.
Correct answer is: STIR (Short TI Inversion Recovery)
Q.99 Which of the following best describes the purpose of 'parallel imaging' in MRI?
To increase the magnetic field strength
To reduce scan time by acquiring fewer phase‑encoding lines
To improve T1 contrast
To eliminate the need for RF pulses
Explanation - Parallel imaging exploits the spatial sensitivity of multiple coil elements to reconstruct images from undersampled k‑space data.
Correct answer is: To reduce scan time by acquiring fewer phase‑encoding lines
Q.100 What does the abbreviation 'MRA' stand for?
Magnetic Resonance Angiography
Magneto‑Radiation Analysis
Magnetic Resonance Ablation
Molecular Resonance Assessment
Explanation - MRA is a set of MRI techniques used to visualize blood vessels.
Correct answer is: Magnetic Resonance Angiography
Q.101 In MR spectroscopy, a peak at 0.9 ppm is most commonly associated with:
Lipid methylene protons
N‑acetylaspartate (NAA)
Creatine
Choline
Explanation - Lipid methylene groups resonate near 0.9 ppm, providing a marker for fatty tissue.
Correct answer is: Lipid methylene protons
Q.102 Which MRI artifact can be minimized by using a higher receiver bandwidth?
Motion artifact
Chemical shift artifact
Aliasing
Gibbs ringing
Explanation - Increasing bandwidth reduces the frequency difference between fat and water, lessening spatial displacement.
Correct answer is: Chemical shift artifact
Q.103 What is the typical slice thickness used for high‑resolution brain MRI at 3 T?
10 mm
5 mm
1 mm
0.2 mm
Explanation - High‑resolution brain imaging commonly uses 1 mm isotropic voxels to balance detail and scan time.
Correct answer is: 1 mm
Q.104 Which MRI technique is especially useful for visualizing the myelin content of white matter?
Magnetization Transfer Imaging (MTI)
Diffusion Tensor Imaging (DTI)
Dynamic Contrast‑Enhanced MRI
Proton Density Imaging
Explanation - MTI measures the exchange between free water and macromolecular protons, providing indirect information on myelin.
Correct answer is: Magnetization Transfer Imaging (MTI)
Q.105 Which of the following best describes the term 'k‑space' in MRI?
The physical location of the patient inside the magnet
The matrix of spatial frequency data collected during scanning
The gradient strength used for slice selection
The RF pulse shape
Explanation - K‑space holds raw frequency‑encoded data; its Fourier transform produces the final image.
Correct answer is: The matrix of spatial frequency data collected during scanning
Q.106 Which MRI sequence is most appropriate for imaging the heart with high blood‑pool signal and good contrast between myocardium and blood?
Balanced SSFP (bSSFP)
T2‑weighted spin‑echo
Diffusion‑weighted imaging
FLAIR
Explanation - bSSFP provides bright blood signal and excellent contrast between myocardium and blood, ideal for cardiac cine imaging.
Correct answer is: Balanced SSFP (bSSFP)
Q.107 What is the primary physical basis for the 'spin‑lattice' (T1) relaxation process?
Exchange of energy between spins and surrounding lattice
Dephasing due to magnetic field inhomogeneities
Diffusion of water molecules
Chemical exchange between metabolites
Explanation - T1 relaxation describes the transfer of energy from excited spins to their environment (the lattice).
Correct answer is: Exchange of energy between spins and surrounding lattice
Q.108 Which of the following is a common clinical use of diffusion‑weighted imaging (DWI)?
Detecting acute ischemic stroke
Assessing liver fat content
Imaging bone fractures
Visualizing pulmonary arteries
Explanation - DWI is highly sensitive to restricted diffusion, making it the preferred sequence for early stroke detection.
Correct answer is: Detecting acute ischemic stroke
Q.109 In MRI, the term 'TR/TE' is often written together. What does this notation indicate?
The ratio of repetition time to echo time
The specific values of repetition time and echo time used in a sequence
The product of TR and TE
The difference between TR and TE
Explanation - TR/TE denotes the chosen repetition and echo times, which together define the contrast weighting of the image.
Correct answer is: The specific values of repetition time and echo time used in a sequence
Q.110 Which MRI technique is specifically designed to suppress the signal from cerebrospinal fluid (CSF) while preserving brain tissue contrast?
FLAIR (Fluid‑Attenuated Inversion Recovery)
STIR (Short TI Inversion Recovery)
MPRAGE (Magnetization‑Prepared Rapid Gradient Echo)
GRE (Gradient Echo)
Explanation - FLAIR uses an inversion time that nulls CSF signal, enhancing detection of lesions near CSF spaces.
Correct answer is: FLAIR (Fluid‑Attenuated Inversion Recovery)
Q.111 What does the abbreviation 'SAR' stand for in MRI safety?
Specific Absorption Rate
Signal‑to‑Artifact Ratio
Standard Acquisition Rate
Spatial Alignment Resolution
Explanation - SAR measures the amount of RF energy absorbed by tissue, with safety limits to avoid excessive heating.
Correct answer is: Specific Absorption Rate
Q.112 Which of the following is the most appropriate MRI technique for visualizing the arterial wall without contrast?
Black‑blood double‑inversion recovery
Time‑of‑Flight MRA
Contrast‑enhanced MRA
Diffusion‑weighted imaging
Explanation - Black‑blood techniques suppress blood signal, allowing direct visualization of the vessel wall.
Correct answer is: Black‑blood double‑inversion recovery
Q.113 In MRI, what is the effect of increasing the flip angle in a spoiled gradient‑echo sequence while keeping TR constant?
Decreases T1 weighting
Increases T2* weighting
Increases signal intensity up to the Ernst angle
Reduces SAR dramatically
Explanation - Signal rises with flip angle until the Ernst angle is reached, after which it declines; this optimizes SNR for given TR.
Correct answer is: Increases signal intensity up to the Ernst angle
Q.114 Which MRI method provides quantitative maps of tissue stiffness by measuring mechanical wave propagation?
Magnetic Resonance Elastography (MRE)
Diffusion Tensor Imaging (DTI)
Dynamic Contrast‑Enhanced MRI (DCE‑MRI)
Magnetization Transfer Imaging (MTI)
Explanation - MRE visualizes shear waves induced in tissue, allowing calculation of stiffness, useful for liver fibrosis assessment.
Correct answer is: Magnetic Resonance Elastography (MRE)
Q.115 Which MRI sequence is most suitable for imaging the prostate with high soft‑tissue contrast?
T1‑weighted spin‑echo
T2‑weighted fast spin‑echo
Diffusion‑weighted imaging
Magnetization‑prepared rapid gradient‑echo (MPRAGE)
Explanation - Prostate tissue shows high T2 signal contrast, making fast spin‑echo T2 imaging optimal for delineation.
Correct answer is: T2‑weighted fast spin‑echo
Q.116 What is the purpose of applying a 'pre‑saturation' pulse before a gradient‑echo acquisition?
To suppress fat signal
To reduce flow artifacts by saturating inflowing blood
To increase T1 contrast
To shorten TE
Explanation - Pre‑saturation suppresses signal from moving spins, minimizing flow‑related artifacts in the final image.
Correct answer is: To reduce flow artifacts by saturating inflowing blood
Q.117 In MR imaging, what does the term 'isotropic voxels' imply?
All dimensions of the voxel are equal, providing uniform resolution in all planes
The voxel size varies across the image
Voxels are shaped like cylinders
Voxel intensity is the same throughout the image
Explanation - Isotropic voxels enable reformatting images in any orientation without loss of spatial resolution.
Correct answer is: All dimensions of the voxel are equal, providing uniform resolution in all planes
Q.118 Which MRI contrast mechanism is primarily responsible for the bright signal of cerebrospinal fluid on T2‑weighted images?
Short T1 relaxation time
Long T2 relaxation time
High proton density
Magnetization transfer
Explanation - CSF has a long T2, so its signal persists during long TE, appearing bright on T2‑weighted scans.
Correct answer is: Long T2 relaxation time
Q.119 Which of the following MRI techniques uses a series of rapid gradient reversals to encode spatial information, enabling very fast imaging?
Echo‑Planar Imaging (EPI)
Spin‑Echo (SE)
Inversion‑Recovery (IR)
Magnetization‑Prepared Rapid Gradient Echo (MPRAGE)
Explanation - EPI rapidly switches gradients to acquire an entire k‑space plane after a single excitation, facilitating fast scans.
Correct answer is: Echo‑Planar Imaging (EPI)
Q.120 What is the main clinical use of the 'STIR' sequence?
Suppressing fat signal in musculoskeletal imaging
Enhancing blood vessels in angiography
Measuring diffusion in brain tumors
Imaging the spinal cord with high T2 contrast
Explanation - STIR nulls fat signal, improving visualization of edema and lesions in soft tissue.
Correct answer is: Suppressing fat signal in musculoskeletal imaging
Q.121 Which MRI parameter is most directly affected by the patient's heart rate during a cardiac gated acquisition?
Repetition time (TR)
Echo time (TE)
Trigger delay (TD)
Flip angle
Explanation - The trigger delay synchronizes data acquisition with a specific phase of the cardiac cycle, depending on heart rate.
Correct answer is: Trigger delay (TD)
Q.122 Which of the following is the primary purpose of 'shimming' in an MRI scanner?
To increase the RF pulse amplitude
To correct inhomogeneities in the main magnetic field (B0)
To cool the superconducting magnet
To reduce patient claustrophobia
Explanation - Shimming adjusts auxiliary coils to improve field uniformity, minimizing artifacts and improving image quality.
Correct answer is: To correct inhomogeneities in the main magnetic field (B0)
Q.123 In MRI, which of the following is a typical indication for using a contrast‑enhanced T1‑weighted sequence?
Assessing bone density
Detecting meniscal tears
Evaluating blood‑brain barrier disruption
Measuring diffusion coefficients
Explanation - Gadolinium contrast extravasates where the blood‑brain barrier is compromised, enhancing T1‑weighted images.
Correct answer is: Evaluating blood‑brain barrier disruption
Q.124 What does the term 'RF pulse' refer to in MRI?
A radiofrequency signal used to tip the net magnetization away from the longitudinal axis
A gradient field that encodes spatial information
The static magnetic field of the scanner
The cooling system for the superconducting magnet
Explanation - RF pulses deliver energy at the Larmor frequency, causing spins to precess into the transverse plane.
Correct answer is: A radiofrequency signal used to tip the net magnetization away from the longitudinal axis
Q.125 Which MRI artifact appears as parallel lines or ghost images displaced along the phase‑encoding direction?
Chemical shift
Ghosting from motion
Aliasing
Susceptibility
Explanation - Patient motion during phase encoding causes duplicate signal copies offset in the phase‑encode direction.
Correct answer is: Ghosting from motion
Q.126 In a T1‑weighted MRI, which tissue typically appears brightest?
Cerebrospinal fluid (CSF)
Fat
White matter
Bone
Explanation - Fat has a short T1 relaxation time, resulting in high signal intensity on T1‑weighted images.
Correct answer is: Fat
Q.127 Which of the following is an advantage of using a phased‑array coil over a single‑loop coil?
Lower SAR
Higher signal‑to‑noise ratio and parallel imaging capability
Simpler hardware configuration
Reduced need for shimming
Explanation - Phased‑array coils combine signals from multiple elements, increasing SNR and enabling accelerated imaging.
Correct answer is: Higher signal‑to‑noise ratio and parallel imaging capability
Q.128 What is the primary clinical use of MR spectroscopy (MRS) in neuroimaging?
Measuring cerebral blood flow
Identifying metabolic changes such as elevated choline in tumors
Assessing bone marrow density
Visualizing vascular malformations
Explanation - MRS detects metabolite concentrations, helping differentiate tumor types and grade based on choline, NAA, and lactate peaks.
Correct answer is: Identifying metabolic changes such as elevated choline in tumors
Q.129 Which MRI sequence is most appropriate for visualizing cartilage defects in the knee?
Proton density‑weighted fat‑suppressed fast spin‑echo
T1‑weighted spin‑echo
Diffusion‑weighted imaging
Time‑of‑Flight MRA
Explanation - PD‑weighted fat‑suppressed sequences provide high contrast between cartilage and surrounding fluid.
Correct answer is: Proton density‑weighted fat‑suppressed fast spin‑echo
Q.130 What is the effect of increasing the receiver bandwidth on image noise?
Noise decreases
Noise remains unchanged
Noise increases
Noise becomes frequency‑dependent
Explanation - Wider bandwidth admits more noise into the system, reducing SNR despite reducing chemical shift artifacts.
Correct answer is: Noise increases
Q.131 Which of the following best describes a '3‑D' MRI acquisition?
Acquisition of a single slice per excitation
Acquisition of a volume with isotropic voxels, allowing reconstruction in any plane
A sequence that uses three gradient directions simultaneously
A technique that images three patients at once
Explanation - 3‑D MRI collects data across a volume, producing isotropic voxels for flexible reformatting.
Correct answer is: Acquisition of a volume with isotropic voxels, allowing reconstruction in any plane
Q.132 In MRI, which parameter determines the spatial resolution along the frequency‑encoding direction?
Field of view (FOV)
Number of phase‑encoding steps
Receiver bandwidth
Repetition time (TR)
Explanation - Resolution in the frequency direction is FOV divided by the number of frequency‑encoding samples.
Correct answer is: Field of view (FOV)