Q.1 What is the primary physiological signal recorded by an Electrocardiogram (ECG)?
Electrical activity of the heart
Blood oxygen saturation
Muscle contraction force
Brain wave activity
Explanation - An ECG measures the electrical potentials produced by cardiac depolarization and repolarization.
Correct answer is: Electrical activity of the heart
Q.2 Which of the following is the standard sampling rate for a high‑resolution ECG system?
200 Hz
500 Hz
1 kHz
10 kHz
Explanation - A 500 Hz sampling frequency provides adequate resolution for clinical ECG while keeping data sizes manageable.
Correct answer is: 500 Hz
Q.3 The Nyquist theorem states that to avoid aliasing, the sampling frequency must be at least:
Equal to the maximum frequency component
Twice the maximum frequency component
Four times the maximum frequency component
Half the maximum frequency component
Explanation - Nyquist criterion requires sampling at ≥ 2× the highest frequency present in the signal.
Correct answer is: Twice the maximum frequency component
Q.4 Which filter is most commonly used to remove baseline wander in ECG signals?
High‑pass filter at 0.5 Hz
Band‑pass filter 0.05–100 Hz
Low‑pass filter at 30 Hz
Notch filter at 50/60 Hz
Explanation - A high‑pass filter around 0.5 Hz eliminates slow baseline drift while preserving QRS complexes.
Correct answer is: High‑pass filter at 0.5 Hz
Q.5 Which artifact commonly contaminates ECG recordings during patient movement?
Power line interference
Muscle noise
Respiratory artifacts
Baseline wander
Explanation - Movement activates skeletal muscles, producing electrical noise that overlays the ECG signal.
Correct answer is: Muscle noise
Q.6 In EEG signal processing, the term "alpha waves" refers to frequencies approximately between:
0.5–4 Hz
4–8 Hz
8–13 Hz
13–30 Hz
Explanation - Alpha waves are dominant in the 8–13 Hz band during relaxed wakefulness.
Correct answer is: 8–13 Hz
Q.7 What is the primary difference between an ECG and an EEG?
ECG records electrical activity of the heart; EEG records brain activity
ECG uses invasive electrodes; EEG uses non‑invasive electrodes
ECG measures voltage; EEG measures current
ECG is recorded in millivolts; EEG in volts
Explanation - ECG captures cardiac electrical signals, whereas EEG captures electrical potentials from the scalp reflecting brain activity.
Correct answer is: ECG records electrical activity of the heart; EEG records brain activity
Q.8 Which imaging modality uses ionizing radiation to create cross‑sectional images of the body?
MRI
CT
Ultrasound
X‑ray radiography
Explanation - Computed Tomography (CT) employs X‑ray beams and detectors to generate 3‑D cross‑sectional images.
Correct answer is: CT
Q.9 In Magnetic Resonance Imaging (MRI), the term "T1 relaxation time" refers to:
Time for spins to lose phase coherence
Time for longitudinal magnetization to return to equilibrium
Time for transverse magnetization to decay
Time between successive RF pulses
Explanation - T1 relaxation is the time constant for recovery of longitudinal magnetization after RF excitation.
Correct answer is: Time for longitudinal magnetization to return to equilibrium
Q.10 Which of the following is NOT a typical noise source in biomedical signal acquisition?
Thermal noise
Motion artifact
Ambient magnetic fields
Digital quantization error
Explanation - Ambient magnetic fields affect MRI but not standard biomedical signal acquisition like ECG or EEG.
Correct answer is: Ambient magnetic fields
Q.11 The Fourier Transform is commonly used in biomedical signal processing to:
Detect peaks in time domain
Analyze frequency components
Increase signal amplitude
Compress data
Explanation - FFT converts a time‑domain signal into its frequency spectrum, aiding feature extraction.
Correct answer is: Analyze frequency components
Q.12 Which sampling theorem ensures that the reconstructed signal is identical to the original for band‑limited signals?
Shannon–Nyquist sampling theorem
Parseval's theorem
Heisenberg uncertainty principle
Rayleigh criterion
Explanation - Shannon–Nyquist theorem states that band‑limited signals can be perfectly reconstructed from samples taken at twice the highest frequency.
Correct answer is: Shannon–Nyquist sampling theorem
Q.13 In an ultrasound system, the speed of sound in soft tissue is approximately:
1500 m/s
3000 m/s
5000 m/s
7000 m/s
Explanation - Ultrasound imaging relies on the 1540 m/s propagation speed of sound in soft tissues.
Correct answer is: 1500 m/s
Q.14 Which image processing operation is used to sharpen images by emphasizing edges?
Gaussian blur
Median filter
Unsharp masking
Low‑pass filtering
Explanation - Unsharp masking subtracts a blurred version of the image to enhance edge contrast.
Correct answer is: Unsharp masking
Q.15 The term "BOLD" in functional MRI stands for:
Brain‑Originating Low‑Intensity Doppler
Blood‑Oxygenation‑Level Dependent
Baseline‑Optimized Light Diffusion
Biochemical Output of Lateral Diffusion
Explanation - BOLD fMRI measures changes in deoxyhemoglobin concentration linked to neural activity.
Correct answer is: Blood‑Oxygenation‑Level Dependent
Q.16 Which of the following best describes the function of an ECG lead II?
Measures potential from right arm to left arm
Measures potential from left leg to right arm
Measures potential from left arm to left leg
Measures potential from right arm to left leg
Explanation - Lead II connects the right arm (negative) to the left leg (positive) and is commonly used for heart rhythm monitoring.
Correct answer is: Measures potential from right arm to left leg
Q.17 What is the purpose of a notch filter at 50/60 Hz in biomedical signal processing?
Remove baseline wander
Eliminate power‑line interference
Suppress muscle noise
Enhance heart rate variability
Explanation - A 50/60 Hz notch filter removes mains electricity interference from recorded signals.
Correct answer is: Eliminate power‑line interference
Q.18 Which feature is commonly extracted from ECG for arrhythmia detection?
R‑R interval
T‑wave amplitude
Signal power spectral density
Baseline wander amplitude
Explanation - R‑R intervals represent time between successive heartbeats and are key for arrhythmia analysis.
Correct answer is: R‑R interval
Q.19 In image segmentation, the "watershed" algorithm is based on:
Color clustering
Edge detection
Morphological erosion
Topographic surface flooding
Explanation - Watershed treats the gradient image as a topographic surface and floods it to delineate regions.
Correct answer is: Topographic surface flooding
Q.20 Which type of sensor is used to acquire electromyography (EMG) signals?
Piezoelectric pressure sensor
Surface electrodes
Accelerometer
Photoplethysmograph
Explanation - EMG measures electrical activity of muscles using electrodes placed on the skin surface.
Correct answer is: Surface electrodes
Q.21 In MRI, what does a T2‑weighted image primarily highlight?
Tissue density
Tissue relaxation time (T2)
Contrast agent concentration
Proton density
Explanation - T2‑weighted images emphasize differences in T2 relaxation times, making fluid appear bright.
Correct answer is: Tissue relaxation time (T2)
Q.22 Which of the following is a common method to reduce motion artifact in fMRI?
Increasing echo time
Using prospective motion correction
Lowering the magnetic field strength
Applying a high‑pass filter
Explanation - Prospective motion correction adjusts gradients in real‑time to compensate for patient movement.
Correct answer is: Using prospective motion correction
Q.23 Which biomedical imaging modality uses radioisotopes to provide functional information?
Computed Tomography (CT)
Magnetic Resonance Imaging (MRI)
Positron Emission Tomography (PET)
Ultrasound
Explanation - PET introduces radioactive tracers that emit positrons, revealing metabolic activity.
Correct answer is: Positron Emission Tomography (PET)
Q.24 A common method to denoise ECG signals without affecting morphology is:
Wavelet thresholding
Median filtering
Band‑pass filtering 5–15 Hz
High‑pass filtering at 50 Hz
Explanation - Wavelet denoising can selectively suppress noise across scales while preserving sharp features like QRS complexes.
Correct answer is: Wavelet thresholding
Q.25 In image processing, what is the effect of applying a Gaussian kernel with a large sigma?
Increases image contrast
Blurs the image
Sharpen edges
Removes high‑frequency noise only
Explanation - A larger sigma in the Gaussian kernel produces stronger low‑pass filtering, resulting in smoother images.
Correct answer is: Blurs the image
Q.26 Which of the following statements best describes the term "aliasing" in signal processing?
When high‑frequency components are incorrectly represented as lower frequencies
When noise is added to the signal
When a signal is compressed
When the signal amplitude is doubled
Explanation - Aliasing occurs when the sampling rate is insufficient, causing frequency folding.
Correct answer is: When high‑frequency components are incorrectly represented as lower frequencies
Q.27 Which type of electrode configuration provides better spatial resolution in EEG?
Three‑electrode setup
High‑density 64‑channel array
Single‑channel lead
Two‑channel differential pair
Explanation - A larger number of electrodes increases the ability to resolve fine spatial patterns of brain activity.
Correct answer is: High‑density 64‑channel array
Q.28 The term "SNR" in biomedical imaging stands for:
Signal‑to‑Noise Ratio
Signal‑to‑Nuclear Ratio
Scanning Noise Reduction
Spectral Noise Rate
Explanation - SNR quantifies the relative level of desired signal versus background noise in an image.
Correct answer is: Signal‑to‑Noise Ratio
Q.29 What is the primary advantage of using a 3‑T MRI scanner over a 1.5‑T scanner?
Lower power consumption
Higher signal‑to‑noise ratio
Faster scan times
Reduced patient discomfort
Explanation - A higher magnetic field increases proton polarization, boosting signal strength and SNR.
Correct answer is: Higher signal‑to‑noise ratio
Q.30 Which of the following best describes the 'phased array' in MRI?
A single large coil
Multiple smaller coils placed close to the patient
A digital array of pixels
An array of RF transmitters
Explanation - Phased‑array coils improve SNR and enable parallel imaging by collecting signals from multiple receive elements.
Correct answer is: Multiple smaller coils placed close to the patient
Q.31 The 'k‑space' in MRI represents:
Spatial domain image
Frequency domain data acquired during scanning
The physical location of the patient's anatomy
The gradient waveform schedule
Explanation - k‑Space stores the raw Fourier transform data that is later converted into spatial images.
Correct answer is: Frequency domain data acquired during scanning
Q.32 Which algorithm is commonly used to register two images taken at different times?
Edge detection
Cross‑correlation
Fourier transform
Morphological opening
Explanation - Cross‑correlation measures similarity between image patches to find the best alignment.
Correct answer is: Cross‑correlation
Q.33 In EMG signal analysis, the term "MUAP" stands for:
Motor Unit Action Potential
Muscle Unit Activity Pulse
Multiple Unit Amplitude Peak
Mean Unit Amplitude Pulse
Explanation - MUAP refers to the electrical signature generated by a single motor unit during contraction.
Correct answer is: Motor Unit Action Potential
Q.34 The term 'SPECT' in medical imaging refers to:
Single‑Photon Emission Computed Tomography
Spectral CT
Synchrotron‑Based CT
Spectral Electromagnetic Tomography
Explanation - SPECT is a nuclear medicine imaging technique that provides 3‑D functional images.
Correct answer is: Single‑Photon Emission Computed Tomography
Q.35 Which of these is a non‑invasive imaging method for detecting bone fractures?
MRI
X‑ray
PET
SPECT
Explanation - X‑ray radiography is the standard non‑invasive method for visualizing bone structures.
Correct answer is: X‑ray
Q.36 What is the typical bandwidth of a clinical ultrasound transducer used for abdominal imaging?
0.1–0.5 MHz
1–5 MHz
10–30 MHz
50–100 MHz
Explanation - Abdominal transducers operate in the 1–5 MHz range to balance penetration and resolution.
Correct answer is: 1–5 MHz
Q.37 In digital image processing, a 'sobel' filter primarily computes:
Image blur
Image edges
Histogram equalization
Color transformation
Explanation - Sobel operators calculate gradient magnitude to detect edges.
Correct answer is: Image edges
Q.38 Which of the following is a major safety concern when operating a CT scanner?
Ultraviolet exposure
Ionizing radiation dose
Electromagnetic interference
Noise level
Explanation - CT uses X‑rays, which carry ionizing radiation that must be carefully controlled.
Correct answer is: Ionizing radiation dose
Q.39 The 'Fourier series' is used to represent signals that are:
Non‑stationary
Periodic
Random
Non‑linear
Explanation - A Fourier series expands periodic signals into sums of sines and cosines.
Correct answer is: Periodic
Q.40 Which filter type is best suited to remove high‑frequency noise while preserving slow physiological signals?
High‑pass filter
Low‑pass filter
Band‑stop filter
All‑pass filter
Explanation - A low‑pass filter attenuates frequencies above a chosen cutoff, keeping slow trends intact.
Correct answer is: Low‑pass filter
Q.41 Which parameter is directly proportional to the depth of penetration in ultrasound imaging?
Frequency
Pulse amplitude
Speed of sound
Attenuation coefficient
Explanation - Higher ultrasound frequency reduces penetration depth due to increased attenuation.
Correct answer is: Frequency
Q.42 The main source of noise in ECG recordings is:
Power‑line interference
Baseline wander
Muscle artefacts
All of the above
Explanation - ECG can be contaminated by power line, baseline, and muscle noise.
Correct answer is: All of the above
Q.43 Which technique is commonly used to reduce motion blur in MRI?
Gradient echo imaging
Parallel imaging
Spin‑echo imaging
Time‑of‑flight imaging
Explanation - Parallel imaging shortens acquisition time, thereby reducing motion artifacts.
Correct answer is: Parallel imaging
Q.44 What does the term 'resolution' refer to in medical imaging?
The ability to detect small details
The speed of image acquisition
The signal strength
The field of view
Explanation - Resolution measures how finely an image can resolve structures.
Correct answer is: The ability to detect small details
Q.45 In signal processing, the term 'aliasing' can be prevented by:
Applying a high‑pass filter
Sampling at a rate below the Nyquist rate
Applying an anti‑aliasing low‑pass filter before sampling
Using a notch filter
Explanation - An anti‑aliasing filter removes high‑frequency components that would otherwise fold into lower frequencies.
Correct answer is: Applying an anti‑aliasing low‑pass filter before sampling
Q.46 Which of the following is a key advantage of MRI over CT?
Lower cost
No ionizing radiation
Higher spatial resolution for bone
Faster imaging time
Explanation - MRI uses magnetic fields and radiofrequency pulses, avoiding ionizing radiation exposure.
Correct answer is: No ionizing radiation
Q.47 What is the function of a 'band‑stop filter' in biomedical signal acquisition?
Eliminate a specific frequency band
Amplify signals in a band
Reduce overall signal amplitude
Convert signal to binary
Explanation - Band‑stop filters remove frequencies within a defined range, useful for removing power line interference.
Correct answer is: Eliminate a specific frequency band
Q.48 In optical imaging, the term 'diffuse optical tomography' refers to:
A method that uses light scattering to reconstruct images
An X‑ray based tomography technique
A high‑energy photon imaging method
A form of PET scan
Explanation - DOT uses near‑infrared light and measures scattered photons to build tissue images.
Correct answer is: A method that uses light scattering to reconstruct images
Q.49 Which of the following describes the 'time‑domain' analysis of a signal?
Examining the signal's frequency content
Examining the signal's amplitude variation over time
Examining the signal's phase space trajectory
Examining the signal's statistical distribution
Explanation - Time‑domain analysis looks at signal amplitude as a function of time.
Correct answer is: Examining the signal's amplitude variation over time
Q.50 Which of the following is NOT a typical component of an ECG lead system?
Ag‑AgCl electrodes
Differential amplifier
Band‑pass filter
X‑ray generator
Explanation - X‑ray generators are part of imaging systems, not ECG acquisition hardware.
Correct answer is: X‑ray generator
Q.51 In digital image processing, 'histogram equalization' is used to:
Blur the image
Enhance contrast
Detect edges
Compress the image
Explanation - Histogram equalization redistributes intensity values to improve overall contrast.
Correct answer is: Enhance contrast
Q.52 Which of the following best describes 'heart rate variability' (HRV)?
Average heart rate over a minute
Variability in the timing of heartbeats
Amplitude variation of the QRS complex
Frequency of arrhythmic episodes
Explanation - HRV measures the fluctuations in intervals between successive heartbeats.
Correct answer is: Variability in the timing of heartbeats
Q.53 What is the typical pixel size in a high‑resolution medical image?
1–2 mm
0.1–0.5 mm
5–10 mm
10–20 mm
Explanation - High‑resolution imaging often uses sub‑millimetre pixel sizes.
Correct answer is: 0.1–0.5 mm
Q.54 The 'b‑value' in diffusion MRI determines:
Signal intensity
Spatial resolution
Diffusion weighting strength
Echo time
Explanation - Higher b‑values increase sensitivity to water diffusion.
Correct answer is: Diffusion weighting strength
Q.55 Which of the following best describes 'magnetoencephalography (MEG)'?
Measures electrical activity from scalp
Measures magnetic fields produced by neuronal currents
Uses ultrasound to image the brain
Measures blood flow in the brain
Explanation - MEG detects the tiny magnetic fields generated by electrical activity in the cortex.
Correct answer is: Measures magnetic fields produced by neuronal currents
Q.56 Which of these is a common artifact in MRI images?
Tissue blooming
Parallel imaging ghosts
Baseline wander
Muscle noise
Explanation - Parallel imaging can produce ghosting artifacts due to undersampling.
Correct answer is: Parallel imaging ghosts
Q.57 Which of the following is a key advantage of using wavelet transform over FFT for ECG analysis?
Better time‑frequency localization
Higher computational speed
Lower memory usage
Simpler implementation
Explanation - Wavelets can capture transient features with good time‑frequency resolution.
Correct answer is: Better time‑frequency localization
Q.58 What is the primary purpose of the 'gating' technique in cardiac MRI?
To synchronize image acquisition with heart rhythm
To reduce motion blur from respiration
To increase scan speed
To improve contrast resolution
Explanation - Cardiac gating ensures images are taken at consistent cardiac phases.
Correct answer is: To synchronize image acquisition with heart rhythm
Q.59 Which type of ultrasound image is typically used for Doppler flow measurements?
B‑mode
C‑mode
M‑mode
Doppler‑mode
Explanation - Doppler mode displays blood flow velocity using frequency shift information.
Correct answer is: Doppler‑mode
Q.60 In CT imaging, the term 'kV' refers to:
X‑ray tube voltage
Photon energy
Kilovolt peak
Kinetic energy
Explanation - kV determines the energy of X‑ray photons and influences penetration and contrast.
Correct answer is: Kilovolt peak
Q.61 Which of these best represents the role of a 'lead‑II' ECG configuration?
Records electrical potential between left and right arms
Records electrical potential between left leg and right arm
Records electrical potential between right arm and left leg
Records electrical potential between left arm and left leg
Explanation - Lead‑II uses the negative electrode on the right arm and positive on the left leg.
Correct answer is: Records electrical potential between right arm and left leg
Q.62 Which of the following is a common method to remove baseline wander from an ECG?
Notch filter at 50/60 Hz
High‑pass filter at 0.5 Hz
Low‑pass filter at 50 Hz
Band‑pass filter 0.05–100 Hz
Explanation - High‑pass filtering removes the slow components responsible for baseline drift.
Correct answer is: High‑pass filter at 0.5 Hz
Q.63 The 'Hounsfield unit' (HU) in CT imaging is defined as:
Ratio of tissue density to water density
Difference in attenuation between tissue and air
Absolute attenuation coefficient of tissue
Ratio of tissue attenuation to bone attenuation
Explanation - HU is calculated as 1000 * (μt − μair)/(μwater − μair).
Correct answer is: Difference in attenuation between tissue and air
Q.64 Which of the following is a common frequency band used to detect epileptic spikes in EEG?
0.5–4 Hz
4–8 Hz
8–13 Hz
20–80 Hz
Explanation - Seizure spikes often exhibit high‑frequency content in the 20–80 Hz band.
Correct answer is: 20–80 Hz
Q.65 What is the main advantage of 'compressed sensing' in MRI?
Increased field of view
Reduced acquisition time
Higher spatial resolution
Lower hardware cost
Explanation - Compressed sensing allows fewer samples while still reconstructing accurate images.
Correct answer is: Reduced acquisition time
Q.66 Which of the following describes the 'echo time (TE)' in MRI?
Time between RF pulse and image acquisition
Time between successive RF pulses
Duration of the RF pulse
Time for the gradient to return to zero
Explanation - TE is the interval from RF excitation to the peak of the echo used for image formation.
Correct answer is: Time between RF pulse and image acquisition
Q.67 Which of the following best defines a 'region of interest (ROI)' in image analysis?
The entire image
A selected sub‑area for further analysis
The area with the highest intensity
The area outside the object
Explanation - ROI is a user‑defined area that focuses computational resources on specific features.
Correct answer is: A selected sub‑area for further analysis
Q.68 What is the purpose of a 'phase‑contrast' MRI technique?
To image static tissue only
To measure blood flow velocity
To enhance bone imaging
To reduce scan time
Explanation - Phase‑contrast MRI encodes velocity information in the phase of the MR signal.
Correct answer is: To measure blood flow velocity
Q.69 Which of the following is a primary source of noise in PET imaging?
Electronic noise
Statistical photon counting noise
Motion artifacts
Thermal noise
Explanation - PET images are dominated by Poisson noise from limited photon counts.
Correct answer is: Statistical photon counting noise
Q.70 In ultrasound imaging, the 'beam‑width' is affected by:
Frequency of the transducer
Temperature of the medium
Pulse amplitude
Time‑of‑flight
Explanation - Higher frequency leads to narrower beam widths and better resolution.
Correct answer is: Frequency of the transducer
Q.71 Which of the following is NOT a typical step in ECG preprocessing?
Baseline correction
Noise filtering
Amplitude scaling
Color space conversion
Explanation - Color conversion is irrelevant for one‑dimensional ECG signals.
Correct answer is: Color space conversion
Q.72 What is the primary difference between 1D and 2D Fourier transforms?
1D handles time, 2D handles space
1D is faster
1D outputs amplitude, 2D outputs phase
1D is for audio, 2D is for images
Explanation - 1‑D FFT processes signals along one axis (time), while 2‑D FFT processes images across two spatial dimensions.
Correct answer is: 1D handles time, 2D handles space
Q.73 Which of these is a key indicator of image quality in CT scans?
Signal‑to‑noise ratio (SNR)
Echo time
Muscle activation level
Pulse frequency
Explanation - SNR measures the clarity of the CT image relative to background noise.
Correct answer is: Signal‑to‑noise ratio (SNR)
Q.74 In a typical 12‑lead ECG, which lead is most useful for detecting right ventricular hypertrophy?
Lead I
Lead III
Lead V1
Lead aVR
Explanation - Lead V1 faces the right ventricle and is sensitive to changes in its size.
Correct answer is: Lead V1
Q.75 Which imaging modality uses high‑frequency mechanical vibrations to generate images?
MRI
CT
Ultrasound
X‑ray
Explanation - Ultrasound employs sound waves (mechanical vibrations) to produce images.
Correct answer is: Ultrasound
Q.76 What is the main advantage of using a 'balanced' gradient echo sequence in MRI?
Higher T2 contrast
Lower specific absorption rate (SAR)
Shorter echo times
Higher T1 contrast
Explanation - Balanced sequences minimize net gradient moments, reducing energy deposition.
Correct answer is: Lower specific absorption rate (SAR)
Q.77 Which of the following is a common preprocessing step for EEG data before performing frequency analysis?
Band‑pass filtering 0.5–45 Hz
Baseline correction to zero
Artifact removal via independent component analysis (ICA)
All of the above
Explanation - Typical EEG preprocessing includes filtering, baseline correction, and artifact removal.
Correct answer is: All of the above
Q.78 The 'magnetic field gradient' in MRI is used to:
Modulate RF power
Encode spatial location
Measure blood flow
Generate contrast agents
Explanation - Gradients linearly vary magnetic field strength, enabling spatial encoding of spins.
Correct answer is: Encode spatial location
Q.79 Which of the following describes a 'super‑resolution' technique in image processing?
Combining multiple low‑resolution images to produce a higher‑resolution output
Reducing noise through Gaussian filtering
Applying a high‑pass filter
Compressing image data using JPEG
Explanation - Super‑resolution reconstructs fine details from several degraded images.
Correct answer is: Combining multiple low‑resolution images to produce a higher‑resolution output
Q.80 What does the 'phase map' in functional MRI represent?
Intensity values across the brain
Temporal delay of BOLD signals
Spatial distribution of blood oxygenation changes
Absolute signal amplitude
Explanation - A phase map visualizes the spatial variation of BOLD phase shifts indicating neural activity.
Correct answer is: Spatial distribution of blood oxygenation changes
Q.81 Which of the following is a key difference between 'static' and 'dynamic' imaging in CT?
Static captures a single time point, dynamic captures multiple time points
Static uses lower radiation, dynamic uses higher
Dynamic requires contrast agents, static does not
Static uses MRI, dynamic uses X‑ray
Explanation - Dynamic imaging tracks changes over time, such as contrast enhancement patterns.
Correct answer is: Static captures a single time point, dynamic captures multiple time points
Q.82 Which of the following is NOT a typical component of a digital ECG signal chain?
Differential amplifier
Analog‑to‑digital converter
Digital‑to‑analog converter
High‑pass filter
Explanation - ECG acquisition is mostly analog‑to‑digital; no need for analog‑to‑digital conversion back.
Correct answer is: Digital‑to‑analog converter
Q.83 In ultrasound, what does 'brightness mode' (B‑mode) refer to?
Displaying depth versus time
Displaying 2‑D echo amplitude
Displaying velocity of flow
Displaying spectral Doppler information
Explanation - B‑mode shows the intensity of echoes as a 2‑D grayscale image.
Correct answer is: Displaying 2‑D echo amplitude
Q.84 Which of the following best describes the purpose of a 'gated' acquisition in MRI?
To synchronize imaging with cardiac or respiratory cycle
To increase spatial resolution
To reduce scan time
To improve contrast between tissues
Explanation - Gating ensures images are taken at consistent phases of physiological motion.
Correct answer is: To synchronize imaging with cardiac or respiratory cycle
Q.85 What is the main advantage of using a 'single‑photon emission computed tomography (SPECT)' over a PET scan?
Higher spatial resolution
Lower cost and availability
Higher temporal resolution
No need for radioactive tracers
Explanation - SPECT systems are generally less expensive and more widely available than PET scanners.
Correct answer is: Lower cost and availability
Q.86 Which of the following best explains the concept of 'aliasing' in digital signal processing?
Over‑sampling a signal
Under‑sampling causing high‑frequency components to appear as lower frequencies
Filtering out high‑frequency noise
Amplifying a signal
Explanation - Aliasing occurs when a signal is sampled below its Nyquist rate, folding frequencies.
Correct answer is: Under‑sampling causing high‑frequency components to appear as lower frequencies
Q.87 Which imaging technique uses time‑of‑flight measurement to quantify blood flow?
Time‑of‑flight magnetic resonance angiography (TOF‑MRA)
Computed tomography angiography (CTA)
Diffusion‑weighted imaging (DWI)
Spectral CT
Explanation - TOF‑MRA exploits flow‑related phase differences to image vessels.
Correct answer is: Time‑of‑flight magnetic resonance angiography (TOF‑MRA)
Q.88 In biomedical image analysis, what does a 'histogram equalization' algorithm primarily aim to improve?
Contrast
Noise level
Spatial resolution
Color saturation
Explanation - Histogram equalization redistributes intensity values to enhance image contrast.
Correct answer is: Contrast
Q.89 Which of the following is a commonly used metric to assess ECG waveform quality?
Heart rate variability
Signal‑to‑noise ratio (SNR)
Blood pressure
Respiratory rate
Explanation - SNR quantifies how much useful ECG signal is present relative to noise.
Correct answer is: Signal‑to‑noise ratio (SNR)
Q.90 Which of the following best describes a 'band‑pass filter' in signal processing?
Passes all frequencies
Passes frequencies within a specific range
Passes only high frequencies
Passes only low frequencies
Explanation - A band‑pass filter allows a defined frequency band to pass while attenuating others.
Correct answer is: Passes frequencies within a specific range
Q.91 In medical imaging, what is the primary purpose of applying a 'mask' to an image?
To remove background noise
To isolate a region of interest (ROI)
To convert image to grayscale
To adjust contrast
Explanation - Masks selectively zero out pixels outside the area of interest for focused analysis.
Correct answer is: To isolate a region of interest (ROI)
Q.92 Which of these is NOT an example of a biomedical imaging modality?
MRI
X‑ray
Infrared spectroscopy
Ultrasound
Explanation - Infrared spectroscopy is a spectroscopic technique, not a traditional imaging modality.
Correct answer is: Infrared spectroscopy
Q.93 What is the main advantage of using a 'high‑density EEG cap' over a standard 10‑20 system?
Improved signal amplitude
Higher temporal resolution
Greater spatial resolution
Lower cost
Explanation - More electrodes provide finer mapping of scalp electrical activity.
Correct answer is: Greater spatial resolution
Q.94 Which of the following best describes the function of an 'electrocardiographic amplifier'?
Amplifies ECG signals for further processing
Amplifies noise in the signal
Amplifies patient heart rate
Amplifies X‑ray intensity
Explanation - Amplifiers increase weak bioelectric potentials to levels suitable for digitization.
Correct answer is: Amplifies ECG signals for further processing
Q.95 In ultrasound, the term 'resolution' refers to:
Ability to detect small anatomical features
Speed of image acquisition
Maximum depth of penetration
Signal bandwidth
Explanation - Resolution dictates how finely structures can be distinguished in the image.
Correct answer is: Ability to detect small anatomical features
Q.96 Which of the following is a common preprocessing step for CT images before segmentation?
Histogram equalization
Median filtering
Edge detection
All of the above
Explanation - Preprocessing may include contrast adjustment, noise reduction, and edge enhancement.
Correct answer is: All of the above
Q.97 What does the term 'dynamic range' refer to in digital imaging?
Number of pixels in the image
Difference between the brightest and darkest detectable intensities
Time resolution of the sensor
Spatial resolution
Explanation - Dynamic range describes the full span of intensity values that can be represented.
Correct answer is: Difference between the brightest and darkest detectable intensities
Q.98 In medical imaging, which of these techniques is commonly used for functional brain mapping?
CT angiography
PET
fMRI
X‑ray fluoroscopy
Explanation - Functional MRI (fMRI) maps brain activity by detecting BOLD signals.
Correct answer is: fMRI
Q.99 Which of the following is a primary advantage of using 'digital subtraction angiography (DSA)'?
Provides functional data
Reduces radiation dose
Visualizes blood vessels with high contrast
Can be performed without contrast agents
Explanation - DSA subtracts pre‑contrast images from post‑contrast to isolate vascular structures.
Correct answer is: Visualizes blood vessels with high contrast
Q.100 In biomedical signal acquisition, which component is responsible for rejecting common‑mode noise?
Differential amplifier
Low‑pass filter
High‑pass filter
Band‑pass filter
Explanation - Differential amplifiers measure potential difference while rejecting common‑mode signals.
Correct answer is: Differential amplifier
Q.101 Which imaging modality is best suited for evaluating bone density?
Dual‑energy X‑ray absorptiometry (DXA)
MRI
Ultrasound
PET
Explanation - DXA uses X‑ray to measure bone mineral density accurately.
Correct answer is: Dual‑energy X‑ray absorptiometry (DXA)
Q.102 What is the purpose of the 'k‑space trajectory' in parallel imaging?
To determine the order of data acquisition
To set the echo time
To adjust the magnetic field strength
To control the RF pulse shape
Explanation - The trajectory defines how k‑space is sampled, influencing image reconstruction.
Correct answer is: To determine the order of data acquisition
Q.103 Which of these is a key characteristic of 'magnetic resonance spectroscopy (MRS)'?
Provides anatomical images
Measures metabolite concentrations
Uses ionizing radiation
Measures blood flow velocity
Explanation - MRS detects chemical shifts of nuclei to quantify biochemical metabolites.
Correct answer is: Measures metabolite concentrations
Q.104 Which of the following best describes a 'phase map' in MR imaging?
Displays spatial variation of magnetic field
Shows magnitude of signal intensity
Shows phase shift of MR signal related to motion or flow
Shows only the static tissues
Explanation - Phase maps capture phase changes due to motion, flow, or susceptibility differences.
Correct answer is: Shows phase shift of MR signal related to motion or flow
Q.105 What is the primary role of a 'lead‑III' ECG configuration?
Detect left ventricular hypertrophy
Detect right ventricular hypertrophy
Detect inferior wall myocardial infarction
Detect anterior wall myocardial infarction
Explanation - Lead III faces the inferior wall and is sensitive to inferior infarctions.
Correct answer is: Detect inferior wall myocardial infarction
Q.106 In a typical ECG lead configuration, which electrode is considered the 'reference'?
Right arm (RA)
Left arm (LA)
Left leg (LL)
All are reference electrodes
Explanation - The left leg electrode is often used as the reference (ground) electrode in standard leads.
Correct answer is: Left leg (LL)
Q.107 Which of the following is a major advantage of using high‑frequency ultrasound transducers?
Greater penetration depth
Higher spatial resolution
Lower cost
Reduced acoustic noise
Explanation - Higher frequency waves provide finer detail at the expense of depth penetration.
Correct answer is: Higher spatial resolution
Q.108 What does the acronym 'DICOM' stand for?
Digital Imaging and Communications in Medicine
Direct Imaging of Computed Magnetic Resonance
Data Interface for Clinical Medical Imaging
Digital Imaging and Compression of Medical Images
Explanation - DICOM is the standard for handling, storing, and transmitting medical imaging information.
Correct answer is: Digital Imaging and Communications in Medicine
Q.109 Which of the following is a common application of a 'Kalman filter' in biomedical signal processing?
Detecting heart rate
Denoising motion‑artifacts in fMRI
Predicting future values of a time series
Enhancing image contrast
Explanation - Kalman filters provide optimal estimates of system states over time, useful for noisy physiological signals.
Correct answer is: Predicting future values of a time series
Q.110 In MRI, a 'spoiled gradient echo' sequence is primarily used to:
Produce T1‑weighted images
Reduce SAR
Provide T2‑weighted images
Measure diffusion
Explanation - Spoiling dephases transverse magnetization, yielding T1 contrast.
Correct answer is: Produce T1‑weighted images
Q.111 Which of these is a typical parameter for evaluating the quality of a PET image?
Signal‑to‑noise ratio (SNR)
Echo time (TE)
Pulse amplitude
Heart rate
Explanation - PET image quality is often measured by SNR, reflecting noise relative to the signal.
Correct answer is: Signal‑to‑noise ratio (SNR)
Q.112 Which of the following best describes the term 'phase‑contrast' in MRI?
Encoding velocity information in the phase of the MR signal
Generating images with contrast based on T1 relaxation
Providing images with enhanced contrast for bone tissue
Encoding spatial information in the magnitude of the MR signal
Explanation - Phase‑contrast MRI is used to map blood flow velocities by encoding phase shifts.
Correct answer is: Encoding velocity information in the phase of the MR signal
Q.113 What does the term 'k‑space' represent in MRI?
Physical location of tissues
Fourier transform of the spatial domain data
Time domain signal acquired during scan
The spatial domain image after reconstruction
Explanation - k‑Space stores raw frequency domain data that is converted to images via FFT.
Correct answer is: Fourier transform of the spatial domain data
Q.114 Which of these is a typical feature extraction technique for EMG signals?
Fast Fourier Transform (FFT)
Wavelet Packet Decomposition
Principal Component Analysis (PCA)
All of the above
Explanation - EMG features are extracted using spectral, wavelet, and statistical methods.
Correct answer is: All of the above
Q.115 What is the primary purpose of using a 'band‑pass filter' when analyzing EEG data?
To remove high‑frequency noise
To remove low‑frequency drift
To isolate the frequency band of interest
To amplify the entire signal
Explanation - Band‑pass filters retain only the frequencies of interest and reject others.
Correct answer is: To isolate the frequency band of interest
Q.116 In ultrasound imaging, what is the main benefit of using a 'sector probe'?
Provides a wide field of view
Allows deep penetration
Produces a narrow field of view
Improves spatial resolution at depth
Explanation - Sector probes have a fan‑shaped field suitable for imaging large structures.
Correct answer is: Provides a wide field of view
Q.117 Which of these is a key difference between 'static' and 'dynamic' MRI imaging?
Static uses a single echo time, dynamic uses multiple
Dynamic captures changes over time, static does not
Static requires contrast agents, dynamic does not
Dynamic is only for functional imaging
Explanation - Dynamic MRI tracks temporal changes, such as perfusion, whereas static provides a snapshot.
Correct answer is: Dynamic captures changes over time, static does not
Q.118 Which of the following is NOT a typical preprocessing step for fMRI time series?
Slice‑timing correction
Spatial smoothing
Intensity normalization
Histogram equalization
Explanation - Histogram equalization is rarely applied to fMRI; preprocessing focuses on motion and spatial alignment.
Correct answer is: Histogram equalization
Q.119 Which of the following best describes the term 'phase map' in optical coherence tomography (OCT)?
Displays depth information of tissue structures
Shows the phase shift of reflected light, providing displacement information
Provides intensity contrast only
Is used only in angiography
Explanation - OCT phase maps reveal micro‑displacements and can detect motion at the micron level.
Correct answer is: Shows the phase shift of reflected light, providing displacement information
Q.120 In the context of image segmentation, what does the 'watershed' algorithm rely on?
Color thresholds
Gradient magnitude and topographic interpretation
Frequency analysis
Histogram equalization
Explanation - Watershed treats image gradients as a topographic surface and segments based on basin filling.
Correct answer is: Gradient magnitude and topographic interpretation
Q.121 Which of the following is an advantage of using a 'low‑pass filter' in biomedical signal processing?
Attenuates high‑frequency noise
Preserves high‑frequency features
Increases the sampling rate
Amplifies the signal
Explanation - A low‑pass filter allows frequencies below the cutoff to pass while attenuating higher ones.
Correct answer is: Attenuates high‑frequency noise
Q.122 Which of these is NOT a type of artifact commonly seen in MRI images?
Ghosting
Aliasing
Motion blur
Baseline wander
Explanation - Baseline wander is an ECG artifact, not an MRI artifact.
Correct answer is: Baseline wander
Q.123 What is the typical purpose of using 'echo planar imaging (EPI)' in fMRI?
To acquire images with high spatial resolution
To acquire images rapidly for dynamic functional studies
To reduce noise
To increase signal intensity
Explanation - EPI captures a full 2‑D image in a single shot, enabling fast fMRI acquisition.
Correct answer is: To acquire images rapidly for dynamic functional studies
Q.124 In biomedical imaging, the term 'contrast agent' refers to:
A device that focuses sound waves
A substance that increases image contrast by altering signal intensity
A sensor for measuring electrical potentials
A software tool for image analysis
Explanation - Contrast agents (e.g., gadolinium, iodine) enhance visibility of tissues in MRI or CT.
Correct answer is: A substance that increases image contrast by altering signal intensity
Q.125 Which of the following best describes 'temporal resolution' in medical imaging?
Ability to resolve small anatomical structures
Speed of image acquisition in time domain
Range of intensities represented
Distance between pixels
Explanation - Temporal resolution quantifies how quickly images can be captured, important for dynamic studies.
Correct answer is: Speed of image acquisition in time domain
Q.126 What does the term 'k‑space filling' refer to in parallel imaging?
The process of acquiring all k‑space data points
The process of sampling k‑space partially and reconstructing it using multiple coils
The process of filling the image with background pixels
The process of adding noise to k‑space
Explanation - Parallel imaging techniques like SENSE or GRAPPA fill undersampled k‑space using coil sensitivities.
Correct answer is: The process of sampling k‑space partially and reconstructing it using multiple coils
Q.127 Which of these is a common type of ultrasound imaging used in obstetrics?
Doppler
B‑mode
M‑mode
Color‑flow imaging
Explanation - B‑mode ultrasound provides grayscale anatomical images of the fetus.
Correct answer is: B‑mode
Q.128 Which of the following best describes the 'gating' technique in cardiac MRI?
Synchronizes image acquisition with heart rhythm
Improves spatial resolution
Reduces motion artifacts from breathing
Enhances contrast between tissues
Explanation - Gating aligns image acquisition to a specific cardiac phase to reduce motion blur.
Correct answer is: Synchronizes image acquisition with heart rhythm
Q.129 What is the primary purpose of the 'echo time' (TE) in an MRI sequence?
Define the time between RF excitation and data acquisition
Control the duration of the RF pulse
Set the magnetic field strength
Determine the spatial resolution
Explanation - TE controls the amount of T2 decay that occurs before sampling the signal.
Correct answer is: Define the time between RF excitation and data acquisition
Q.130 In medical imaging, the term 'attenuation coefficient' refers to:
The ability of tissue to absorb X‑rays or sound waves
The speed of sound in tissue
The magnetic susceptibility of tissue
The contrast enhancement level
Explanation - Attenuation coefficient describes how much an imaging modality’s signal is reduced when passing through tissue.
Correct answer is: The ability of tissue to absorb X‑rays or sound waves
Q.131 Which of the following best describes the role of an 'electrocardiographic filter bank'?
Amplifies ECG signals
Provides multiple frequency bandpass filters to extract specific ECG components
Generates artifact signals
Increases noise levels
Explanation - A filter bank decomposes the ECG into components like P, QRS, T for analysis.
Correct answer is: Provides multiple frequency bandpass filters to extract specific ECG components
Q.132 Which of these is a typical application of 'principal component analysis (PCA)' in medical imaging?
Noise reduction in ECG
Dimensionality reduction for image segmentation
Increasing scan speed
Enhancing contrast
Explanation - PCA reduces feature space, aiding segmentation algorithms by highlighting variance directions.
Correct answer is: Dimensionality reduction for image segmentation
Q.133 In CT imaging, what does the term 'tube current' (mA) primarily affect?
Image noise level
Penetration depth
Resolution
Contrast agent uptake
Explanation - Higher tube current increases photon flux, reducing quantum noise in the image.
Correct answer is: Image noise level
Q.134 Which of the following best describes 'saturation recovery' in MRI?
A technique to suppress the signal from certain tissues
A technique to reduce SAR
A method to accelerate imaging
A method to increase T1 contrast
Explanation - Saturation recovery uses a pre‑pulse to null specific tissue signals before imaging.
Correct answer is: A technique to suppress the signal from certain tissues
Q.135 In an ECG, the 'QT interval' represents:
Time from onset of QRS to end of T wave
Duration of ventricular depolarization only
Duration of ventricular repolarization only
Time from onset of P wave to end of QRS
Explanation - QT interval covers ventricular depolarization and repolarization.
Correct answer is: Time from onset of QRS to end of T wave
Q.136 Which of the following is a typical pre‑processing step for CT images before segmentation?
Gaussian smoothing
Edge detection
Thresholding
All of the above
Explanation - Pre‑processing may include filtering, edge enhancement, and thresholding to improve segmentation.
Correct answer is: All of the above
Q.137 What does the term 'temporal filtering' refer to in biomedical signal analysis?
Filtering in the frequency domain
Filtering in the time domain
Filtering based on anatomical location
Filtering based on spatial resolution
Explanation - Temporal filtering operates directly on the signal's time sequence to remove unwanted components.
Correct answer is: Filtering in the time domain
Q.138 In medical imaging, the term 'contrast‑to‑noise ratio (CNR)' refers to:
Signal intensity difference divided by noise level
Difference in signal intensity between two tissues
Overall brightness of an image
Contrast agent concentration
Explanation - CNR measures how distinct a feature is from background noise.
Correct answer is: Signal intensity difference divided by noise level
Q.139 Which of the following is an example of a 'functional' MRI technique?
T1‑weighted imaging
T2‑weighted imaging
Functional MRI (fMRI) using BOLD contrast
Diffusion‑weighted imaging (DWI)
Explanation - Functional MRI measures brain activity rather than static anatomy.
Correct answer is: Functional MRI (fMRI) using BOLD contrast
Q.140 Which of these is a primary source of noise in a typical ECG recording?
Muscle activity (EMG) noise
Power line interference
Baseline wander
All of the above
Explanation - ECG signals are often contaminated by EMG, power line, and baseline drift noise.
Correct answer is: All of the above
Q.141 In ultrasound, the term 'focal zone' refers to:
The area where sound waves converge for maximum intensity
The depth of the deepest image point
The width of the transducer array
The bandwidth of the emitted signal
Explanation - The focal zone is the region of greatest acoustic focus and resolution.
Correct answer is: The area where sound waves converge for maximum intensity
Q.142 In medical imaging, 'phantoms' are used for:
Testing and calibrating imaging systems
Treating patients
Storing patient data
Providing contrast agents
Explanation - Phantoms simulate human tissues for system validation and quality control.
Correct answer is: Testing and calibrating imaging systems
Q.143 Which of the following is NOT a typical imaging modality for brain imaging?
MRI
CT
X‑ray fluoroscopy
PET
Explanation - X‑ray fluoroscopy is primarily used for real‑time imaging of moving structures, not detailed brain imaging.
Correct answer is: X‑ray fluoroscopy
Q.144 Which of the following is the main difference between 'static' and 'dynamic' CT imaging?
Static uses a single exposure, dynamic captures changes over time
Dynamic uses lower radiation dose
Dynamic images have higher spatial resolution
Static images use contrast agents, dynamic do not
Explanation - Dynamic CT tracks temporal changes such as contrast passage, while static is a single snapshot.
Correct answer is: Static uses a single exposure, dynamic captures changes over time
Q.145 In biomedical signal processing, what does the term 'down‑sampling' refer to?
Increasing the sampling rate
Reducing the sampling rate
Changing the signal amplitude
Filtering high‑frequency components
Explanation - Down‑sampling decreases the number of samples by discarding data, often after anti‑alias filtering.
Correct answer is: Reducing the sampling rate
Q.146 What is the main purpose of a 'lead‑I' configuration in a 12‑lead ECG?
To detect left ventricular hypertrophy
To detect right ventricular hypertrophy
To assess the frontal plane electrical axis
To measure the inferior wall activity
Explanation - Lead I provides a view of the heart's electrical activity along the frontal plane.
Correct answer is: To assess the frontal plane electrical axis
Q.147 Which of the following best describes the concept of 'super‑resolution' in image processing?
Combining multiple low‑resolution images to generate a high‑resolution output
Reducing noise by averaging
Enhancing contrast via histogram equalization
Compressing image data for storage
Explanation - Super‑resolution reconstructs high‑detail images from multiple degraded captures.
Correct answer is: Combining multiple low‑resolution images to generate a high‑resolution output
Q.148 Which of these is a key component of a 'digital ECG signal chain'?
Analog‑to‑digital converter
RF amplifier
X‑ray detector
Ultrasound transducer
Explanation - ECG signals are analog voltages that must be digitized for processing.
Correct answer is: Analog‑to‑digital converter
Q.149 In MRI, what is the effect of increasing the 'flip angle' in an excitation pulse?
Increases T2 weighting
Reduces T1 weighting
Increases the angle of spin precession, affecting signal intensity
Decreases signal intensity
Explanation - A larger flip angle tips more magnetization into the transverse plane, altering contrast.
Correct answer is: Increases the angle of spin precession, affecting signal intensity
Q.150 Which of the following is a common artifact observed in CT images?
Aliasing
Ghosting
Motion blur
Baseline wander
Explanation - Motion blur is due to patient movement during image acquisition.
Correct answer is: Motion blur
Q.151 What does the term 'SNR' stand for in biomedical signal processing?
Signal‑to‑Noise Ratio
Standard Noise Ratio
Signal‑to‑Neural Ratio
Sampling Noise Rate
Explanation - SNR is the ratio of the signal power to the noise power in a measurement.
Correct answer is: Signal‑to‑Noise Ratio
Q.152 Which of the following is an example of a 'time‑of‑flight' imaging technique?
Diffusion‑weighted imaging (DWI)
CT angiography
TOF‑MRA
PET
Explanation - Time‑of‑flight MR angiography uses flow‑related phase differences for vessel imaging.
Correct answer is: TOF‑MRA
Q.153 In EEG analysis, what does a 'power spectral density (PSD)' plot show?
Amplitude of each frequency component
Phase relationships between electrodes
Temporal evolution of the signal
Spatial distribution of activity
Explanation - PSD displays the power of the signal across frequency bands.
Correct answer is: Amplitude of each frequency component
Q.154 Which of the following imaging modalities uses high‑frequency mechanical waves?
MRI
CT
Ultrasound
X‑ray
Explanation - Ultrasound relies on high‑frequency acoustic waves to generate images.
Correct answer is: Ultrasound
Q.155 What is the primary purpose of a 'phase‑contrast' sequence in MRI?
To enhance T1 contrast
To visualize blood flow velocity
To reduce artifacts from patient motion
To measure tissue diffusion
Explanation - Phase contrast encodes velocity as phase shifts, enabling flow mapping.
Correct answer is: To visualize blood flow velocity
Q.156 Which of the following best describes the 'k‑space' sampling in MRI?
Direct acquisition of spatial domain data
Acquisition of frequency domain data for image reconstruction
Measurement of tissue density
Acquisition of time‑domain signals
Explanation - k‑Space stores the Fourier transform of the spatial data.
Correct answer is: Acquisition of frequency domain data for image reconstruction
Q.157 In CT imaging, which parameter primarily determines the image's contrast resolution?
Tube voltage (kV)
Slice thickness
Detector size
Pitch
Explanation - Higher kV reduces contrast between tissues by increasing photon energy.
Correct answer is: Tube voltage (kV)
Q.158 Which of these is a typical application of 'compressed sensing' in MRI?
Reducing scan time by undersampling
Increasing spatial resolution
Improving contrast
Decreasing patient discomfort
Explanation - Compressed sensing allows accurate reconstruction from fewer samples, speeding up imaging.
Correct answer is: Reducing scan time by undersampling
Q.159 In biomedical signal processing, the term 'filterbank' refers to:
A set of filters covering different frequency bands
A single broadband filter
A mechanical filter in ultrasound
A type of data storage device
Explanation - A filterbank splits signals into multiple subbands for detailed analysis.
Correct answer is: A set of filters covering different frequency bands
Q.160 Which of these is a key advantage of 'dynamic contrast‑enhanced MRI' (DCE‑MRI)?
Provides high spatial resolution
Measures vascular permeability and perfusion
Reduces radiation exposure
Requires no contrast agent
Explanation - DCE‑MRI tracks contrast kinetics to assess tissue vascular properties.
Correct answer is: Measures vascular permeability and perfusion
Q.161 What does the term 'baseline wander' in ECG signals refer to?
Drift of the ECG signal baseline over time
Random spikes in the signal
High‑frequency noise
Amplification errors
Explanation - Baseline wander is a slowly varying offset caused by respiration or electrode movement.
Correct answer is: Drift of the ECG signal baseline over time
Q.162 Which of these is a commonly used software tool for image segmentation?
Matlab
ImageJ
R
All of the above
Explanation - ImageJ is widely used for biomedical image analysis and segmentation.
Correct answer is: ImageJ
Q.163 What is the main purpose of a 'band‑pass filter' when processing biomedical signals?
To isolate a specific frequency range and remove unwanted frequencies
To amplify all frequencies equally
To suppress low‑frequency components only
To suppress high‑frequency components only
Explanation - Band‑pass filtering preserves frequencies in a defined range while attenuating others.
Correct answer is: To isolate a specific frequency range and remove unwanted frequencies
Q.164 In MRI, the term 'spoiling' refers to:
Eliminating residual transverse magnetization
Increasing signal intensity
Reducing scan time
Increasing resolution
Explanation - Spoiling destroys residual transverse components to achieve desired contrast.
Correct answer is: Eliminating residual transverse magnetization
Q.165 Which of the following best describes the function of a 'gain stage' in an ECG amplifier?
Amplifies the small electrical potentials from the heart to a measurable level
Reduces the input signal to avoid saturation
Adds noise to the signal
Converts analog to digital
Explanation - The gain stage boosts the microvolt‑level ECG signals for further processing.
Correct answer is: Amplifies the small electrical potentials from the heart to a measurable level
Q.166 Which of these is a common preprocessing step in fMRI data analysis?
Slice‑timing correction
Motion correction
Spatial smoothing
All of the above
Explanation - fMRI preprocessing typically includes these three steps to prepare data for analysis.
Correct answer is: All of the above
Q.167 Which of the following best describes the 'Hounsfield unit' scale?
A scale of relative X‑ray attenuation with 0 HU for water
A scale of signal intensity in MRI
A scale of acoustic impedance
A scale of blood oxygen saturation
Explanation - The Hounsfield scale assigns water a value of 0 and air -1000 HU.
Correct answer is: A scale of relative X‑ray attenuation with 0 HU for water
Q.168 In a typical ECG lead configuration, which electrode serves as the 'ground' or reference?
Right arm (RA)
Left arm (LA)
Left leg (LL)
Right leg (RL)
Explanation - Left leg is commonly used as the reference in standard ECG leads.
Correct answer is: Left leg (LL)
Q.169 Which of the following is a typical method to remove motion artifacts from fMRI data?
Rigid body realignment
Band‑pass filtering
High‑pass filtering
Gaussian smoothing
Explanation - Realignment corrects for head motion by aligning each volume to a reference.
Correct answer is: Rigid body realignment
Q.170 In medical imaging, what does 'contrast‑enhancement' refer to?
Increasing image brightness uniformly
Using a contrast agent to improve differentiation between tissues
Reducing noise
Adding color to grayscale images
Explanation - Contrast agents selectively enhance certain structures, improving diagnostic visibility.
Correct answer is: Using a contrast agent to improve differentiation between tissues
Q.171 Which of these is a common type of ultrasound probe?
Linear array
Curved array
Phased array
All of the above
Explanation - All listed probe types are widely used for different imaging tasks.
Correct answer is: All of the above
Q.172 Which of the following is a primary parameter of a 'high‑pass filter' used in ECG preprocessing?
Cutoff frequency
Stopband attenuation
Passband ripple
All of the above
Explanation - All parameters define how the filter shapes the ECG signal.
Correct answer is: All of the above
Q.173 What does 'SNR' stand for in the context of MRI?
Signal‑to‑Noise Ratio
Signal‑to‑Neural Ratio
Standard Noise Ratio
Sampling Noise Rate
Explanation - SNR is a key metric indicating image quality relative to noise.
Correct answer is: Signal‑to‑Noise Ratio
Q.174 Which of the following is a typical use of 'Diffusion‑Weighted Imaging (DWI)' in MRI?
Detecting bone fractures
Assessing brain ischemia
Visualizing liver lesions
Measuring blood flow velocity
Explanation - DWI is sensitive to water diffusion changes, aiding stroke diagnosis.
Correct answer is: Assessing brain ischemia
Q.175 In biomedical imaging, what is the purpose of using a 'phantom'?
To calibrate imaging equipment
To store patient data
To provide contrast agents
To deliver radiation therapy
Explanation - Phantoms mimic human tissues for quality control and calibration.
Correct answer is: To calibrate imaging equipment