Radiography / Medical Imaging Technology Licensing Exam preparation SET 2

Q1

Which factor, when increased, most significantly raises the efficiency of bremsstrahlung production in an X-ray tube?

A

Increasing the tube voltage (kVp)

B

Reducing the focal spot size

C

Using a low-atomic-number target material

D

Increasing the tube current (mA)

Q2

When the filament current is increased, the immediate effect on the X-ray tube is:

A

Higher electron flow, resulting in increased tube current (mA)

B

Higher tube voltage (kV)

C

Faster rotation of the anode

D

Thinner X-ray beam

Q3

In a digital radiography system, why is it important to maintain a consistent beam quality (kVp) for a given anatomical region?

A

To ensure uniform pixel size

B

To keep the focal spot size stable

C

To avoid variations in image noise and contrast due to changes in photon energy distribution

D

To maintain constant exposure time

Q4

Which material is most commonly used to express HVL values for diagnostic X-ray beams?

A

Aluminum

B

Copper

C

Lead

D

Tungsten

Q5

What is the main advantage of using a high-frequency (e.g., 60 lp/cm) grid over a low-frequency (e.g., 10 lp/cm) grid for chest radiography?

A

Higher grid ratio

B

Reduced grid cut-off visibility

C

Lower patient dose

D

Wider field coverage

Q6

A chest PA is taken with 125 kVp and 4 mAs. To double the image density without changing kVp, the mAs should be:

A

8 mAs

B

2 mAs

C

6 mAs

D

10 mAs

Q7

What type of distortion is most likely when a cylindrical object is placed at an angle to the central ray?

A

Magnification distortion

B

Geometric (shape) distortion

C

Radiographic density distortion

D

Scatter distortion

Q8

What is the purpose of the 'Erasure Cycle' in a CR reader?

A

To sharpen the edges of the image

B

To remove residual latent images from the plate

C

To increase the contrast of the resulting image

D

To calibrate the laser intensity

Q9

The high-tension transformer in an X-ray generator is a:

A

Step-down transformer

B

Step-up transformer

C

Isolation transformer with 1:1 ratio

D

Variable autotransformer

Q10

A radiographer adjusts the collimator so that the X-ray field is just larger than the image receptor. What is this practice called?

A

Over-collimation

B

Under-collimation

C

Optimal collimation

D

Field matching

Q11

If an X-ray tube is operated at a lower kVp than the rating chart value, the generated heat per mAs will:

A

Increase

B

Decrease

C

Remain the same

D

Become unpredictable

Q12

Which of the following chemicals is primarily responsible for removing unexposed silver halide crystals during the fixing stage?

A

Sodium thiosulfate

B

Hydroquinone

C

Sodium sulfite

D

Phenidone

Q13

Which of the following image artifacts is most likely caused by a misaligned laser scanner in a CR reader?

A

Moiré pattern across the image

B

Uniform fogging of the entire image

C

Vertical streaks or bands

D

Loss of overall image contrast

Q14

According to Nepal radiology guidelines, the minimum retention period for adult radiology images stored in a PACS is:

A

5 years

B

10 years

C

15 years

D

Lifetime

Q15

In digital radiography QC, the acceptable value for the coefficient of variation (CV) in a uniformity test is:

A

Less than 1%

B

Less than 3%

C

Less than 5%

D

Less than 10%

Q16

Which deterministic effect has the highest documented threshold dose?

A

Hair follicle depletion at 3 Gy

B

Cataract formation at 0.5 Gy

C

Skin erythema at 2 Gy

D

Infertility at 1 Gy

Q17

Which action best demonstrates the application of the 'shielding' principle during a portable radiographic exam in a neonatal ICU?

A

Placing a lead-rubber shield between the incubator and the X-ray tube

B

Increasing the mAs to compensate for decreased kVp

C

Holding the infant closer to the tube to improve image sharpness

D

Turning off the room lights to improve visibility

Q18

Which factor most influences the sensitivity of a film badge to low-dose exposure?

A

Type of developing solution

B

Film speed

C

Size of the badge

D

Color of the badge holder

Q19

The workload (W) used in primary barrier design calculations refers to the:

A

Total number of exposures performed annually

B

Average radiation output in mAs per week

C

Maximum mAs used in a single exposure

D

Average tube current multiplied by exposure time

Q20

In pediatric chest radiography, the recommended collimation practice is to:

A

Collimate to the exact area of clinical interest, avoiding unnecessary exposure of adjacent tissues

B

Collimate to the full size of the image receptor to ensure coverage

C

Use a fixed collimation setting for all ages

D

Open collimation wide to reduce the need for repeat exposures

Q21

According to Nepalese regulations, the maximum permissible dose to the lens of the eye for a worker in a controlled area is:

A

15 mSv yr⁻¹

B

20 mSv yr⁻¹

C

50 mSv yr⁻¹

D

150 mSv yr⁻¹

Q22

In a PA projection of the chest, why is the patient's back against the image receptor?

A

To allow posterior electrodes to be visualized clearly

B

To reduce magnification of cardiac structures

C

To ensure that the thorax - the thickest part - is closer to the detector, optimizing beam intensity and image quality

D

To minimize motion artifact from breathing

Q23

Which of the following is the most appropriate method to prepare a child for an extremity radiograph?

A

Explain the procedure thoroughly without physical contact

B

Use a pediatric restraint device if the child is uncooperative

C

Force the child's limb into position quickly

D

Avoid using any immobilization tools

Q24

The correct sequence for ensuring proper use of central ray and collimation during an examination is:

A

Position patient, apply markers, set collimation, align CR

B

Set collimation, position patient, align CR, apply markers

C

Position patient, align CR, set collimation, apply markers

D

Apply markers, position patient, align CR, set collimation

Q25

For a lateral abdominal examination, the patient's position should be:

A

Supine, rotated 90 degrees.

B

Lateral decubitus with the affected side up.

C

Lateral decubitus with the affected side down.

D

Standing upright.

Q26

During a lateral lumbar spine projection, the patient's arms should be placed where to avoid superimposition of the humeral heads?

A

Crossed over the chest

B

Along the sides of the body

C

Behind the head

D

Raised above the head

Q27

When taking an AP view of the shoulder with the patient in a seated position, which of the following is essential to obtain a diagnostic image?

A

Arm abducted 30° with hand on the thigh

B

Arm placed in internal rotation with hand on the abdomen

C

Arm placed in neutral rotation with elbow flexed 90°

D

Arm abducted 90° with hand on the head

Q28

During a lateral view of the maxillary sinus, the central ray is aimed at:

A

The lateral canthus

B

The infraorbital margin

C

The outer canthus

D

The midpoint of the mandible

Q29

When acquiring an AP scapular Y view, the patient's head should be positioned:

A

Neutral, looking straight ahead

B

Extended, looking upward

C

Flexed, chin tucked to chest

D

Rotated towards the side being imaged

Q30

In a PA kidney view of an IVP examination, the image receptor should be positioned:

A

Anterior to the patient

B

Posterior to the patient

C

Laterally aligned

D

At a 45° angle

Q31

In HSG images, a "pseudopolyp" appearance is most commonly caused by:

A

Intracavitary contrast pooling within a small uterine diverticulum

B

True endometrial polyps

C

Calcified uterine fibroids

D

Contrast extravasation into the bladder

Q32

Which factor most directly influences the spatial resolution in CT imaging?

A

Reconstruction kernel selection

B

Display monitor brightness

C

Patient body habitus

D

Scan time duration

Q33

If a CT image has a window width (WW) of 400 HU and a window level (WL) of 50 HU, what is the range of Hounsfield Units displayed?

A

-150 to 250 HU

B

-150 to 550 HU

C

-350 to 450 HU

D

-350 to 250 HU

Q34

Which contrast media property is most directly related to the risk of causing contrast-induced nephropathy?

A

Viscosity

B

Osmolality

C

Atomic number

D

Color

Q35

In CT angiography, the use of a saline chaser after contrast injection primarily serves to:

A

Reduce contrast viscosity

B

Decrease the total iodine dose

C

Push residual contrast from the injection line into the patient, reducing streak artifacts

D

Increase the arterial attenuation by 30 %

Q36

On a T2-weighted image, how does the signal intensity of Cerebrospinal Fluid (CSF) typically appear?

A

Dark (Hypointense)

B

Bright (Hyperintense)

C

Isointense with grey matter

D

Void of signal

Q37

Which of the following best describes the effect of gradient cross-talk in MRI?

A

Image blurring due to mutual interference between gradients

B

Increased field strength

C

Patient heating

D

RF signal loss

Q38

Which of the following best describes the MRI safety Zone classification system?

A

Zone I: unrestricted access; Zone IV: MRI scanner room

B

Zone I: scanner room; Zone IV: unrestricted access

C

Zone I: MRI console; Zone IV: patient waiting area

D

Zone I: scanner room; Zone IV: administrative office

Q39

For evaluating a suspected tear of the glenoid labrum in the shoulder, which plane is most demonstrative?

A

Axial

B

Coronal

C

Sagittal

D

Oblique coronal

Q40

In M-mode imaging of the fetal heart, the vertical axis represents:

A

Depth (distance)

B

Time

C

Amplitude

D

Velocity

Q41

A 24-year-old primigravida at 20 weeks shows a thickened, echogenic placenta with multiple linear calcifications. What condition does this suggest?

A

Placenta previa

B

Placental insufficiency

C

Placenta accreta

D

Calcific (mature) placenta

Q42

Which radionuclide is most commonly used for single-photon emission computed tomography (SPECT) because of its 140 keV gamma photon and 6-hour half-life?

A

Technetium-99m

B

Iodine-131

C

Fluorine-18

D

Gallium-67

Q43

A 'Fan-beam' collimator is typically used in which of the following examinations?

A

Whole body bone scan

B

Brain SPECT imaging

C

Lung perfusion scan

D

Thyroid uptake scan

Q44

What is the recommended maximum permissible activity of 131I that a patient can be released to home care, according to Nepal Nuclear Safety guidelines?

A

740 MBq

B

370 MBq

C

1,110 MBq

D

5,550 MBq

Q45

Which of the following statements explains why high-osmolality ionic contrast media are rarely used in modern CT imaging?

A

They provide insufficient radiodensity

B

They have a higher incidence of adverse reactions and renal toxicity

C

They are more expensive than non-ionic agents

D

They cannot be administered intravenously

Q46

A patient who had a contrast-enhanced MRI 6 hours ago develops a diffuse, painful rash and arthralgia. Which laboratory test would help confirm a delayed hypersensitivity reaction?

A

Serum tryptase

B

Serum IgE level

C

Complete blood count with eosinophilia

D

Urine iodine concentration

Q47

Which of the following QC tests ensures that the X-ray beam is centered to the light field?

A

Half-value layer test

B

Collimation accuracy test

C

kVp accuracy test

D

Exposure reproducibility test

Q48

In a lateral ankle (mortise) projection, what degree of plantar flexion is required?

A

0-5 degrees

B

15-20 degrees

C

30-35 degrees

D

Full dorsiflexion

Q49

Which anatomical landmark is critical for determining the correct level of the diaphragm on a chest radiograph?

A

6th posterior costal arch

B

5th posterior costal arch

C

7th posterior costal arch

D

8th posterior costal arch

Q50

A frontal chest radiograph depicts a double-shadow on the right side of the mediastinum in a newborn. This is most likely due to:

A

Mediastinal tumor

B

Persistent left superior vena cava (normal variant)

C

Right aortic arch

D

Thymic hyperplasia

Q51

When a radiographer selects a window width (WW) of 1200 HU for a head CT, which of the following is the most likely visual outcome?

A

High contrast between gray matter and white matter

B

Reduced contrast, allowing both bone and soft tissue to be seen together

C

Increased image noise perception

D

Loss of bone detail due to saturation

Q52

If free intraperitoneal air is suspected beneath the right hemidiaphragm, which decubitus position should be chosen?

A

Right lateral decubitus

B

Left lateral decubitus

C

Supine

D

Prone

Q53

In MRI, the phenomenon where protons absorb and emit energy is called nuclear magnetic resonance. Which property of the proton is fundamental to this phenomenon?

A

Its electrical charge

B

Its mass

C

Its intrinsic angular momentum (spin)

D

Its atomic number

Q54

In a CT protocol, decreasing the tube rotation time while keeping mAs constant will:

A

Increase image noise

B

Decrease patient dose

C

Increase tube current (mA)

D

Reduce scan length

Q55

The relationship between object size and image sharpness in radiography is governed by:

A

The inverse square law

B

Beam hardening effects

C

Geometric unsharpness principles

D

Photoelectric effect dominance

Q56

Which component converts the analog charge packet from each pixel into a digital value in a DR system?

A

Charge-sensitive amplifier (CSA) + analog-to-digital converter (ADC)

B

Scintillator

C

TFT gate driver

D

High-voltage bias supply

Q57

A patient's orthopedic fixation plate is made of stainless steel. What is the recommended MRI safety decision?

A

Proceed without restriction because stainless steel is non-magnetic

B

Label the patient as MR unsafe and cancel the exam

C

Verify the plate's specific alloy and follow MR conditional guidelines

D

Replace the plate before scanning

Q58

Detective Quantum Efficiency (DQE) of an imaging detector is defined as the ratio of:

A

Output signal-to-noise ratio to input signal-to-noise ratio

B

Mean pixel value to exposure index

C

Number of detected photons to emitted photons

D

Spatial resolution to contrast resolution

Q59

For a PA projection of the skull (Caldwell), the central ray exits through which anatomical structure?

A

Foramen magnum

B

Nasion

C

Inion

D

Sella turcica

Q60

Which component is specifically used in a capacitor-discharge generator to store energy before the exposure is triggered?

A

Rectifier

B

Autotransformer

C

Capacitor

D

Inverter

Q61

In iterative reconstruction, the "system model" typically includes which of the following components?

A

Only the statistical noise model of the detector

B

The forward projection operator, detector response, and statistical noise model

C

The filtered back-projection ramp filter and a regularization term

D

The patient-specific attenuation map derived from a prior scan

Q62

Which of the following does NOT affect the magnitude of the anode heel effect?

A

Anode angle

B

Target material

C

Field size

D

Tube current (mA)

Q63

When using a digital radiography detector, the collimator jaws should be closed as tightly as possible around the anatomy of interest primarily to:

A

Limit scattered radiation from reaching the detector

B

Prevent detector saturation from excess exposure

C

Reduce the amount of electronic noise in the system

D

Increase the field of view for better patient positioning

Q64

If the source-to-object distance (SOD) is kept constant and the SID is increased, what is the effect on image magnification?

A

Magnification decreases

B

Magnification increases

C

Magnification remains unchanged

D

Magnification first increases then decreases

Q65

What is the purpose of the internal baffle (or anti-backscatter shield) located inside the tube housing?

A

Reduce backscatter radiation reaching the focal spot

B

Increase the tube voltage capability

C

Provide additional filtration of low-energy photons

D

Support the anode rotor bearings

Q66

When positioning a pediatric patient for a PA kidney view in IVP, which modification is essential compared with adult positioning?

A

Use a smaller image receptor

B

Decrease the SID to about 80 cm

C

Increase the SID to 150 cm

D

Place the patient in a seated position

Q67

When using a collimator, what happens to the image contrast as the field size is decreased (tight collimation)?

A

Contrast decreases due to more scatter

B

Contrast increases due to less scatter

C

Contrast remains unchanged

D

Contrast decreases due to beam hardening

Q68

In a thyroid nodule that contains micro-calcifications, an artifact appears as a series of short, closely spaced, bright lines that fan out from the calcifications. This is most consistent with which artifact?

A

Comet-tail artifact

B

Ring-down artifact

C

Acoustic enhancement

D

Mirror image artifact

Q69

When the source-to-image distance (SID) is decreased while the object-to-image distance (OID) stays the same, what is the effect on geometric unsharpness?

A

Geometric unsharpness decreases

B

Geometric unsharpness increases

C

No change in geometric unsharpness

D

Image magnification doubles

Q70

When evaluating the spatial resolution of a flat-panel detector using a line-pair phantom, the highest line-pair frequency that can be resolved with a contrast of at least 20% is called the:

A

Modulation Transfer Function (MTF) cutoff

B

Limiting Resolution

C

Spatial Frequency at 20% MTF

D

Nyquist Frequency

Q71

To avoid the risk of introducing infection into the peritoneal cavity (pelvic peritonitis) during HSG, which of the following is most critical?

A

Using a high kVp setting

B

Maintaining strict aseptic technique during catheterization

C

Using a grid for all projections

D

Performing the exam in the prone position

Q72

In the context of X-ray production, what happens to the total X-ray output (intensity) if the kVp is doubled, assuming mA and time are constant?

A

Intensity doubles

B

Intensity increases by a factor of 4

C

Intensity increases approximately by a factor of 50 (kVp squared)

D

Intensity remains the same

Q73

Which pulse sequence is most sensitive to the magnetic susceptibility effects of acute intracerebral hemorrhage?

A

Spin Echo

B

Gradient Echo

C

Fast Spin Echo

D

Inversion Recovery

Q74

During a high-dose pelvic exam, a radiographer needs 500 mAs at 120 kVp. The tube rating chart permits a maximum of 350 mAs for a single exposure at this kVp. Which of the following is the most appropriate action?

A

Split the exposure into two 250 mAs exposures with appropriate cooling time

B

Increase the kVp to 130 kVp to reduce heat factor

C

Decrease the mA and increase the exposure time to keep 500 mAs total

D

Proceed with the 500 mAs exposure and monitor tube temperature

Q75

During a zygomatic arch projection, which structure typically appears as a radiolucent "U" shape on the image?

A

Zygomatic arch

B

Temporomandibular joint

C

Mandibular condyle

D

Maxillary tuberosity

Q76

An anti-scatter grid placed too close to the patient may cause which of the following artifacts?

A

Grid cutoff artifact

B

Motion blur

C

Beam hardening

D

Focus blooming

Q77

After completing a double-contrast barium enema, the radiographer should verify complete colonic evacuation before discharging the patient. Which method is most reliable?

A

Ask the patient if they feel empty

B

Obtain a single supine abdominal radiograph

C

Perform a post-evacuation prone radiograph of the entire colon

D

Measure the volume of expelled barium

Q78

A patient undergoing CT abdomen receives a contrast agent with a concentration of 370 mg I/ml. If the planned total iodine load for the study is 40 g, what total volume of contrast should be administered?

A

108 ml

B

108 ml (rounded to nearest ml)

C

108 ml (exact)

D

108 ml (approx.)

Q79

A patient unable to lie flat due to severe dyspnoea requires a chest radiograph. Which positioning aid is most suitable to obtain a diagnostic image?

A

Use a portable upright chair for a standing PA chest view

B

Place a wedge under the patient's back on the table

C

Tilt the table to 30° while the patient remains supine

D

Use a rolling stretcher in the supine position

Q80

For which of the following tissues is the deterministic threshold dose the lowest, according to ICRP recommendations?

A

Thyroid gland

B

Lens of the eye

C

Bone marrow

D

Skin

Q81

In a true AP knee view, the central ray is angled caudad by about 10° to avoid overlapping of which structure?

A

Patella

B

Fibula

C

Tibial tuberosity

D

Popliteal fossa

Q82

Which of the following is the most appropriate size for an anatomical side marker used on adult radiographs according to NHPC guidelines?

A

30 mm × 30 mm square

B

10 mm × 10 mm square

C

45 mm × 45 mm square

D

15 mm × 15 mm square

Q83

Why is molybdenum commonly used as the envelope material for mammography x-ray tubes rather than regular leaded glass?

A

Molybdenum has a lower atomic number, reducing attenuation of low-energy photons

B

Molybdenum is more resistant to thermal shock from high-power exposure

C

Molybdenum provides inherent filtration of high-energy x-rays

D

Molybdenum improves the tube's vacuum seal durability

Q84

A DR detector has a fixed matrix of 2048 × 2048 pixels. If the same detector is used to image a 35 cm × 35 cm field of view (FOV) and later the image is cropped to a 25 cm × 25 cm region of interest, what happens to the effective spatial resolution within the cropped area?

A

Effective pixel size becomes smaller, so spatial resolution improves

B

Effective pixel size becomes larger, so spatial resolution degrades

C

Resolution stays the same because pixel count is unchanged

D

Noise level doubles, offsetting any gain in resolution

Q85

A portable x-ray unit has a fixed anode angle of 4°. Which limitation is most likely encountered when using this unit for adult chest imaging at high mAs?

A

Reduced heat-capacity of the focal spot leading to tube overheating.

B

Excessive magnification of the image due to a large effective focal spot.

C

Increased heel effect causing non-uniform exposure across the chest.

D

Loss of beam collimation resulting in increased scatter.

Q86

When acquiring an abdominal radiograph in a pediatric patient, how is the source-to-image distance (SID) typically adjusted compared with an adult?

A

Increased by about 10 cm

B

Decreased by about 10 cm

C

Kept the same as adult

D

Reduced to 80 cm

Q87

If a 6:1 grid has a Bucky factor of 2.5, what is the approximate Bucky factor for a 12:1 grid of the same line frequency, assuming other parameters remain unchanged?

A

3.5

B

4.5

C

5.0

D

6.0

Q88

The acceptable half-value layer (HVL) range for a 70 kVp conventional radiography beam is:

A

1.5 - 2.0 mm Al

B

2.0 - 2.5 mm Al

C

2.5 - 3.0 mm Al

D

3.0 - 3.5 mm Al

Q89

When the kilovoltage peak (kVp) is increased, which of the following changes occurs in the x-ray spectrum reaching the image receptor?

A

Decreased beam hardening

B

Increased photoelectric effect

C

Increased beam hardening

D

Decreased patient dose

Q90

Oblique projections involve angling the central ray relative to the standard anatomical planes. Which definition best describes an oblique projection in radiography?

A

Central ray perpendicular to transverse plane

B

Central ray at 90 degrees to the image receptor

C

Central ray angled between horizontal and vertical

D

Patient rotated 90 degrees from standard position

Q91

A radiology department records a contrast reaction log. Which of the following data elements is NOT essential for quality-assurance purposes?

A

Date and time of reaction onset

B

Patient's weight and age

C

The specific contrast agent and dose administered

D

Patient's occupational exposure history

Q92

If a transducer operates at a frequency of 7 MHz, what is the approximate wavelength in soft tissue (speed of sound ≈ 1540 m/s)?

A

0.22 mm

B

0.22 cm

C

0.22 m

D

0.22 µm

Q93

What is the principal clinical role of FDG PET/CT in evaluating lymphoma?

A

Staging, restaging, and treatment response assessment

B

Replacing all need for tissue biopsy

C

Primary screening in healthy populations

D

Measuring serum tumor markers

Q94

In a coronal T1-weighted MRI of the brain, the structure appearing as a thin, low-signal-intensity line extending from the anterior to posterior perforated substance and separating the orbitofrontal cortex from the temporal pole is the:

A

Optic tract

B

Lateral orbitofrontal sulcus

C

Temporal pole sulci

D

Cerebral peduncle

Q95

In a mastoid (lateral) view, the presence of the petrous ridge superimposed over the mastoid air cells indicates:

A

Correct positioning

B

Excessive caudal angulation

C

Insufficient head rotation away from the side being imaged

D

Too high kVp

Q96

Which parameter on a tube rating chart is most directly influenced by increasing the beam filtration?

A

Exposure factor

B

Heat factor

C

Maximum permissible mA

D

Cooling time

Q97

Which sonographic characteristic is diagnostic of a choledochal cyst?

A

Cystic dilatation of the extra-hepatic bile duct

B

Cystic dilatation of intra-hepatic bile ducts

C

Thickened gallbladder wall with sludge

D

Intra-hepatic calcifications

Q98

Which phenomenon describes a gradual loss of stored signal in a TLD element after prolonged storage before read-out?

A

Fogging

B

Saturation

C

Fading

D

Scintillation

Q99

For a CT pulmonary embolism protocol, what is the preferred breath-hold instruction for the patient during image acquisition?

A

Normal tidal breathing

B

Deep inspiration and hold breath for 10–15 seconds

C

Exhale fully and hold breath

D

Rapid shallow breaths

Q100

Which of the following does NOT use ionizing radiation?

A

X-ray

B

CT

C

MRI

D

Nuclear scintigraphy