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RRB Radiographer practice questions

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Question 1Professional Ability – Radiography and Medical Imaging

For a radiographer occupationally exposed to ionizing radiation, what is the ICRP-recommended occupational effective dose limit averaged over five consecutive years?

  1. 20 mSv per year averaged over five consecutive years Correct answer.
  2. 1 mSv per year averaged over five consecutive years
  3. 500 mSv per year averaged over five consecutive years
  4. 50 mSv per year averaged over five consecutive years

Explanation

ICRP recommends an occupational effective dose limit of 20 mSv per year averaged over five consecutive years, with a maximum of 50 mSv in any single year. The 1 mSv limit applies to members of the public, not radiation workers. A 500 mSv annual limit would be far above the threshold for deterministic effects.

Question 2Professional Ability – Radiography and Medical Imaging

A PA projection of the chest is obtained with the patient facing the image receptor. Which statement correctly describes the path of the X-ray beam?

  1. It passes from the left side of the thorax to the right side.
  2. It enters the anterior thorax and exits posteriorly.
  3. It enters the posterior thorax and exits anteriorly. Correct answer.
  4. It passes from the right side of the thorax to the left side.

Explanation

In a PA projection the X-ray beam enters the posterior surface and exits anteriorly, with the patient facing the image receptor. An AP projection would instead enter anteriorly and exit posteriorly. Lateral projections pass side to side and are described separately.

Question 3Professional Ability – Radiography and Medical Imaging

What is the primary function of intensifying screens in a cassette used with radiographic film?

  1. To measure absorbed dose during the exposure
  2. To convert X-rays into light that exposes film Correct answer.
  3. To filter low-energy X-rays before they reach the patient
  4. To focus the X-ray beam onto a smaller field

Explanation

Intensifying screens contain phosphors that absorb X-ray photons and emit visible light, which then exposes the film. This light conversion reduces the radiation dose needed compared with direct film exposure. Filtration, dosimetry, and beam restriction are performed by other components.

Question 4Professional Ability – Radiography and Medical Imaging

A radiograph is produced using 10 mAs at 70 kVp and has acceptable receptor exposure. If the radiographer increases the mAs to 20 while keeping kVp constant, what is the expected effect on receptor exposure?

  1. It halves the receptor exposure.
  2. It increases by a factor of four.
  3. It remains unchanged because kVp controls receptor exposure.
  4. It doubles the receptor exposure. Correct answer.

Explanation

With kVp held constant, receptor exposure is directly proportional to mAs. Doubling mAs from 10 to 20 therefore doubles the number of X-ray photons reaching the receptor. kVp affects both exposure and penetrating power, but it is not the only exposure control.

Question 5Professional Ability – Radiography and Medical Imaging

A radiographer is selecting an anti-scatter grid for a lateral lumbar spine examination on an adult. Which grid ratio provides the greatest scatter cleanup while requiring the highest mAs compensation?

  1. 16:1 Correct answer.
  2. 5:1
  3. No grid is used
  4. 8:1

Explanation

A 16:1 grid has the highest ratio listed and removes the greatest proportion of scattered radiation before it reaches the receptor. Higher-ratio grids also require greater mAs compensation because they remove more of the primary beam as well. Lower ratios provide less cleanup and need less compensation.

Question 6Professional Ability – Radiography and Medical Imaging

Which situation is an absolute contraindication to the use of barium sulfate as a contrast medium?

  1. Need to evaluate esophageal varices
  2. Suspected gastrointestinal perforation Correct answer.
  3. Suspected gastric ulcer
  4. History of mild constipation

Explanation

Barium sulfate is contraindicated when gastrointestinal perforation is suspected because leakage into the peritoneal cavity can cause barium peritonitis. A water-soluble iodinated contrast agent is preferred when perforation is a concern. The other listed conditions do not absolutely prohibit barium use.

Question 7Professional Ability – Radiography and Medical Imaging

In computed radiography, what happens when a photostimulable phosphor plate is exposed to X-rays?

  1. A latent image is stored in the phosphor until laser stimulation releases light. Correct answer.
  2. The plate immediately emits visible light in proportion to the incident exposure.
  3. The plate stores the image permanently until it is heated to a very high temperature.
  4. The plate converts X-rays directly into an electrical signal without light.

Explanation

In computed radiography the phosphor plate stores X-ray energy as a latent image. The reader scans the plate with a laser, which stimulates emission of light proportional to the stored signal. A photomultiplier tube converts that light into an electrical signal for image formation.

Question 8Professional Ability – Radiography and Medical Imaging

When performing a portable chest radiograph on a patient under contact precautions, which practice best protects the radiographer and other patients?

  1. Place the cassette on the bed without a cover and clean it after leaving the room.
  2. Wear gloves only and reuse the same cassette for the next patient without cleaning.
  3. Use a cassette cover and disinfect the cassette before leaving the room. Correct answer.
  4. Ask the patient to hold the cassette directly against the chest during exposure.

Explanation

Contact precautions require barriers between the radiographer, the equipment, and the patient's environment. A cassette cover protects the cassette, and disinfecting it before removal prevents contaminating the portable unit and other patients. Hand hygiene completes the chain of infection control.

Question 9Professional Ability – Radiography and Medical Imaging

A radiograph is made with a 1.2 mm focal spot, a source-to-object distance (SOD) of 100 cm, and an object-to-image receptor distance (OID) of 20 cm. Which change will reduce geometric unsharpness the most?

  1. Decrease SOD to 80 cm with OID unchanged
  2. Use a larger focal spot of 2.0 mm
  3. Increase the OID to 30 cm while keeping the SOD unchanged
  4. Increase SOD to 120 cm with OID unchanged Correct answer.

Explanation

Geometric unsharpness increases with larger focal spots and greater object-to-image receptor distance, and it decreases with greater source-to-object distance. Increasing SOD from 100 cm to 120 cm reduces the penumbra, while increasing OID or focal spot size makes it worse.

Question 10Professional Ability – Radiography and Medical Imaging

A radiographer wants to increase subject contrast between bone and soft tissue in a skeletal radiograph. Which interaction change would most directly produce this effect?

  1. More photoelectric absorption in bone than in soft tissue Correct answer.
  2. Increased pair production in the patient at routine diagnostic X-ray energies
  3. Increased Compton scattering in soft tissue during the exposure
  4. Increased coherent scattering throughout the patient's body

Explanation

Photoelectric absorption is strongly dependent on atomic number and photon energy, so bone absorbs more X-rays than soft tissue at diagnostic energies. This differential absorption is the main source of subject contrast in skeletal radiography. Compton scatter tends to reduce contrast, and pair production is not relevant at diagnostic energies.

Question 11Professional Ability – Radiography and Medical Imaging

A radiographer reduces the collimated field size for an AP knee radiograph while keeping all other exposure factors unchanged. What is the most likely effect on the image?

  1. Spatial resolution decreases because fewer photons are produced.
  2. Greater scattered radiation reaches the receptor, reducing contrast.
  3. Magnification increases because the object-to-image distance increases.
  4. Less scattered radiation reaches the receptor, improving contrast. Correct answer.

Explanation

Collimation restricts the irradiated tissue volume, so less Compton scatter is generated and less reaches the image receptor. With scatter reduced, subject contrast improves while geometric factors such as magnification and focal-spot blur remain unchanged.

Question 12Professional Ability – Radiography and Medical Imaging

A radiograph of a femur is obtained with the central ray angled along the long axis of the bone rather than perpendicular to it. The bone is projected longer than its actual length. Which term describes this appearance?

  1. Elongation Correct answer.
  2. Foreshortening
  3. Magnification
  4. Penumbra

Explanation

Distortion occurs when the projected image differs in shape or size from the object. Angling the central ray along the long axis projects the bone longer than its true length, which is elongation; foreshortening is the opposite.

Question 13Professional Ability – Radiography and Medical Imaging

Before beginning a radiographic examination, the radiographer asks the patient to state their full name and date of birth and compares these with the request. What is the main purpose of this practice?

  1. To calculate the patient's radiation dose
  2. To decide whether a grid is needed
  3. To determine the required exposure factors for the examination
  4. To prevent wrong-patient imaging and mislabelling Correct answer.

Explanation

Two identifiers confirm that the examination and the resulting images belong to the correct person. This prevents wrong-patient imaging, mislabelling, and incorrect downstream treatment.

Question 14Professional Ability – Radiography and Medical Imaging

An AP abdomen radiograph is made using AEC with the center chamber selected, but the exposure terminates early and the image is noisy. The patient's spine is not centered over the selected chamber. Which action is most appropriate for the repeat?

  1. Increase the kVp by 15% and keep using the same AEC chamber
  2. Use a chamber over the anatomy or manual exposure Correct answer.
  3. Use a higher-ratio grid
  4. Reduce the source-to-image distance for the repeat

Explanation

AEC chambers terminate exposure when the selected chamber receives the preset dose. If the chamber is not under the spine, the exposure can end early and produce a noisy image; re-centering and choosing an appropriate chamber, or using manual technique, corrects this.

Question 15Professional Ability – Radiography and Medical Imaging

A radiographer lowers mAs to reduce patient dose for a lumbar spine radiograph, and the resulting image appears grainy. Which factor most directly explains the graininess?

  1. Quantum mottle from too few photons Correct answer.
  2. Increased focal-spot blur from a smaller anode angle
  3. Grid cutoff caused by incorrect centering
  4. Excessive collimation of the X-ray field

Explanation

When mAs is reduced too far, too few X-ray quanta reach the receptor and statistical fluctuation produces quantum mottle. The image looks grainy even though geometric blur and grid performance may be normal.

Question 16Professional Ability – Radiography and Medical Imaging

A patient scheduled for an intravenous urogram reports a previous mild reaction to iodinated contrast and has asthma. Which action is most appropriate before contrast is given?

  1. Consult the radiologist about risk assessment and premedication according to protocol Correct answer.
  2. Proceed with the examination without any change because the previous reaction was mild
  3. Substitute oral barium sulfate for the iodinated contrast
  4. Double the contrast dose to improve opacification

Explanation

A prior contrast reaction and asthma increase the risk of an adverse reaction, so the radiologist should review the indication and apply departmental premedication or alternative-imaging policy. The radiographer should not independently proceed, substitute barium, or increase the dose.

Question 17Professional Ability – Radiography and Medical Imaging

Which projection best demonstrates the acromioclavicular joint with minimal superimposition of the clavicle and acromion?

  1. Transthoracic lateral projection centered on the humeral shaft
  2. Axillary projection with the arm abducted to 90 degrees
  3. PA projection of the entire chest with full inspiration
  4. AP AC joint with 10- to 15-degree cephalad angulation Correct answer.

Explanation

The AC joint is evaluated with a small-field AP projection and a 10- to 15-degree cephalad angle to open the joint space. Chest and humerus projections include the region but do not provide optimal AC joint detail.

Question 18Professional Ability – Radiography and Medical Imaging

A portable AP chest radiograph shows a uniform decrease in density toward both lateral edges of the image. The patient is centered, and the exposure factors are appropriate. Which factor is the most likely cause?

  1. Incorrect selection of the AEC chamber
  2. Patient rotation during the exposure
  3. Cephalad angulation of the X-ray tube
  4. A grid used outside its focal range Correct answer.

Explanation

Grid cutoff causes a symmetric loss of density toward the image edges when the beam is off-center relative to the grid or the SID is outside the grid's focal range. Rotation and tube angulation tend to produce asymmetric density changes rather than this pattern.

Question 19Professional Ability – Radiography and Medical Imaging

A PA wrist radiograph is repeated because the scaphoid appears foreshortened. Which positioning error most likely produced this appearance?

  1. Excessive source-to-image distance
  2. Ulnar deviation of the wrist
  3. Insufficient collimation
  4. Radial deviation of the wrist Correct answer.

Explanation

The scaphoid is best shown with ulnar deviation, which extends the bone and reduces foreshortening. Radial deviation rotates the scaphoid into a foreshortened position and should be avoided for this view.

Question 20Professional Ability – Radiography and Medical Imaging

A digital radiography department performs quality control on a flat-panel detector. Which test directly assesses uniform response across the detector area?

  1. Collimator alignment test
  2. Focal-spot size measurement
  3. Flat-field uniformity test Correct answer.
  4. Kilovoltage peak accuracy test

Explanation

A flat-field uniformity test exposes the detector uniformly and measures variation in pixel response, revealing dead pixels, gain drift, and artifacts. Tube and beam tests such as kVp accuracy and collimator alignment do not assess detector uniformity.

Question 21Professional Ability – Radiography and Medical Imaging

Which radiation protection principle directs the radiographer to use the lowest exposure that still provides the required diagnostic information?

  1. The reciprocity law
  2. The line-focus principle
  3. As low as reasonably achievable (ALARA) Correct answer.
  4. The anode heel effect

Explanation

ALARA is the optimization principle that requires radiation dose to be kept as low as reasonably achievable while still obtaining the needed diagnostic information. The line-focus principle describes effective focal spot geometry, the anode heel effect describes intensity variation along the anode-cathode axis, and the reciprocity law relates mAs to exposure time and tube current.

Question 22Professional Ability – Radiography and Medical Imaging

Which SI unit is used to express equivalent dose and effective dose in occupational radiation monitoring?

  1. Coulomb per kilogram (C/kg)
  2. Gray (Gy)
  3. Sievert (Sv) Correct answer.
  4. Becquerel (Bq)

Explanation

Equivalent dose and effective dose are measured in sieverts; the sievert applies radiation and tissue weighting factors to reflect biological risk. The gray measures absorbed dose, the becquerel measures radioactivity, and the coulomb per kilogram measures air kerma or exposure.

Question 23Professional Ability – Radiography and Medical Imaging

Which shielding device is placed on the patient to reduce dose to the reproductive organs during an AP pelvis radiograph?

  1. Gonadal shield Correct answer.
  2. Lead apron
  3. Collimator
  4. Thyroid shield

Explanation

Gonadal shielding reduces dose to the radiosensitive reproductive organs during pelvic radiography when it does not obscure the anatomy of interest. A thyroid shield is used for the neck, a lead apron protects the operator or patient's trunk, and a collimator limits the field but is not worn by the patient.

Question 24Professional Ability – Radiography and Medical Imaging

In a computed radiography reader, what is the function of the laser beam directed at the photostimulable phosphor plate?

  1. It stimulates trapped electrons to release light proportional to the X-ray exposure Correct answer.
  2. It heats the phosphor plate to fix the latent image
  3. It preconditions the plate before X-ray exposure
  4. It erases residual signal from the plate after reading

Explanation

The laser in a CR reader scans the exposed phosphor plate and releases trapped electrons, producing light proportional to the original X-ray exposure. A separate erasure step uses bright light to clear residual signal so the plate can be reused.

Question 25Professional Ability – Radiography and Medical Imaging

A digital radiograph has an exposure index substantially above the manufacturer's target range. What does this most likely indicate?

  1. The image has optimal spatial resolution but poor contrast
  2. The image is underexposed and will show increased quantum mottle
  3. The image has excessive receptor exposure and may need a lower mAs Correct answer.
  4. The image was acquired with incorrect collimation

Explanation

Exposure index indicates the amount of signal reaching the digital receptor; a value above the target range suggests overexposure. Because digital windowing can hide brightness changes, the radiographer must check EI and repeat with lower mAs if appropriate.

Question 26Professional Ability – Radiography and Medical Imaging

A radiographer uses a focused grid and angles the X-ray tube across the grid lines rather than toward the grid center. Which artifact is most likely?

  1. Quantum mottle
  2. Anode heel effect
  3. Grid cut-off Correct answer.
  4. Pincushion distortion

Explanation

Angling the tube across the grid lines causes the grid strips to absorb primary radiation, producing grid cut-off and a visible loss of density. Focused grids must be aligned with the central ray and used within their specified focal range.

Question 27Professional Ability – Radiography and Medical Imaging

Which action best reduces patient dose during a fluoroscopic procedure?

  1. Using continuous fluoroscopy at maximum mA
  2. Removing collimation to improve visibility
  3. Using last-image hold and pulsed fluoroscopy Correct answer.
  4. Increasing the fluoroscopic exposure time per frame

Explanation

Pulsed fluoroscopy reduces the number of frames and last-image hold avoids additional exposure when viewing a static image. Continuous maximum mA, removing collimation, and increasing exposure time per frame all increase patient dose.

Question 28Professional Ability – Radiography and Medical Imaging

During a portable chest radiograph, where should the radiographer stand to minimize occupational radiation dose?

  1. Directly behind the image receptor
  2. At 90 degrees to the primary beam and at the greatest practical distance Correct answer.
  3. Next to the X-ray tube housing
  4. Directly in the primary beam behind the patient

Explanation

Scattered radiation is strongest near the patient and in the direction of the primary beam, so standing at 90 degrees and at the greatest practical distance lowers occupational dose. The radiographer should also wear a lead apron and use a dosimeter.

Question 29Professional Ability – Radiography and Medical Imaging

During an intravenous urogram, a patient develops urticaria, wheezing, and hypotension shortly after iodinated contrast is injected. What is the most appropriate immediate action?

  1. Continue the injection at a slower rate and observe the patient
  2. Give oral diphenhydramine and discharge the patient after 30 minutes
  3. Elevate the legs and give oral fluids only
  4. Stop the injection, call for emergency help, and support airway and circulation per protocol Correct answer.

Explanation

Urticaria, wheezing, and hypotension after contrast injection suggest an anaphylactoid reaction; the priority is to stop the injection, call for emergency help, and support airway, breathing, and circulation. Epinephrine is the first-line drug for anaphylaxis with bronchospasm or hypotension, and the patient requires continuous monitoring.

Question 30Professional Ability – Radiography and Medical Imaging

Which quality control test evaluates whether the radiographic X-ray field aligns with the image receptor and collimator indicators?

  1. Uniformity test
  2. Beam alignment test Correct answer.
  3. Sensitometry
  4. Focal spot size measurement

Explanation

The beam alignment test checks that the light field, X-ray field, and image receptor coincide, helping prevent unnecessary irradiation and inaccurate cropping. Sensitometry evaluates processing, focal spot measurement evaluates resolution, and uniformity evaluates detector response.

Question 31Professional Ability – Radiography and Medical Imaging

When all other exposure factors are held constant, which factor primarily determines the contrast of a radiograph?

  1. Milliampere-seconds
  2. Source-to-image receptor distance
  3. Kilovoltage peak Correct answer.
  4. Focal spot size

Explanation

Kilovoltage peak controls the energy and penetrating power of the X-ray beam, which changes subject contrast and the scale of contrast recorded by the image receptor. Milliampere-seconds mainly affects photon quantity and overall receptor exposure, not the primary contrast control.

Question 32Professional Ability – Radiography and Medical Imaging

Which projection of the cervical spine is performed to demonstrate the intervertebral foramina?

  1. Lateral projection
  2. Anteroposterior projection
  3. Posteroanterior projection
  4. Oblique projection Correct answer.

Explanation

An oblique projection of the cervical spine is taken at approximately 45 degrees to open the intervertebral foramina on the side away from the central ray. The lateral projection demonstrates alignment and disk spaces, while the AP projection shows vertebral bodies and uncovertebral joints.

Question 33Professional Ability – Radiography and Medical Imaging

Which contrast medium is normally used for a routine single-contrast barium enema?

  1. Iodinated water-soluble contrast
  2. Barium sulfate suspension Correct answer.
  3. Carbon dioxide gas
  4. Gadolinium-based contrast

Explanation

Barium sulfate is the standard positive contrast medium for a routine barium enema because it coats the colon and produces high radiographic density. Water-soluble iodinated contrast is reserved for situations such as suspected perforation, where barium could cause peritonitis.

Question 34Professional Ability – Radiography and Medical Imaging

A radiographer is positioning a patient for an ankle mortise projection. How should the foot be rotated to open the lateral clear space?

  1. No rotation from the AP position
  2. Internal rotation of 15 to 20 degrees Correct answer.
  3. External rotation of 15 to 20 degrees
  4. Internal rotation of 45 degrees

Explanation

The mortise projection requires 15 to 20 degrees of internal rotation so the lateral malleolus moves anteriorly and the joint space opens. Excessive internal rotation, such as 45 degrees, closes the mortise and causes superimposition of the talus and malleoli.

Question 35Professional Ability – Radiography and Medical Imaging

A focused grid labeled for use at 180 cm is used at a 100 cm source-to-image receptor distance. What is the most likely effect on the radiograph?

  1. Peripheral density loss from grid cutoff Correct answer.
  2. Increased center contrast from grid cleanup
  3. Uniform increased density across the image
  4. Motion artifact from a longer exposure

Explanation

A focused grid is designed for a specific focal range. Using it at 100 cm when it is labeled for 180 cm causes the peripheral grid lines to misalign with the beam, producing grid cutoff and decreased density at the lateral edges.

Question 36Professional Ability – Radiography and Medical Imaging

A PA chest radiograph is being made with automatic exposure control. Which chamber selection is most appropriate?

  1. Both lateral chambers Correct answer.
  2. All three chambers
  3. Upper center chamber only
  4. Center chamber only

Explanation

For a PA chest, the two lateral chambers are selected because they lie over the lung fields and are less influenced by the dense mediastinum and spine. Using the center chamber alone can terminate the exposure before the lungs receive adequate receptor exposure.

Question 37Professional Ability – Radiography and Medical Imaging

Which patient condition is a contraindication to the use of barium sulfate as a gastrointestinal contrast medium?

  1. Chronic constipation
  2. Suspected bowel perforation Correct answer.
  3. A permanent colostomy
  4. Diverticulosis

Explanation

Barium sulfate is contraindicated when bowel perforation is suspected because leakage into the peritoneal cavity can cause severe peritonitis. A water-soluble iodinated contrast medium is preferred in that setting.

Question 38Professional Ability – Radiography and Medical Imaging

A computed radiography image consistently shows a sharp white line running parallel to the direction the imaging plate travels through the reader. What is the most likely cause?

  1. Patient motion during exposure
  2. Imaging plate scratch or debris Correct answer.
  3. Incorrect source-to-image receptor distance
  4. Focal spot blur from the tube

Explanation

A reproducible sharp line that follows the direction of plate transport is characteristic of a scratch, dust, or foreign material on the photostimulable phosphor plate or in the reader. Because the artifact persists across patients, it points to the plate or reader rather than to patient motion or exposure factors.

Question 39Professional Ability – Radiography and Medical Imaging

A lateral chest radiograph shows the posterior ribs separated rather than superimposed, and the sternum is seen in profile. Which positioning error best explains the rib appearance?

  1. The exposure is made at end-inspiration
  2. The affected side is farther from the image receptor
  3. The patient is rotated from a true lateral position Correct answer.
  4. The central ray is angled cephalad

Explanation

In a true lateral chest, the posterior ribs should be nearly superimposed. Separation of the posterior ribs indicates rotation of the thorax, even if the sternum still appears in profile; accurate positioning requires the midsagittal plane parallel to the image receptor and the arms elevated.

Question 40Professional Ability – Radiography and Medical Imaging

Which change most directly reduces geometric unsharpness when imaging a small bone?

  1. Increasing the part thickness
  2. Lowering the kilovoltage
  3. Using a smaller focal spot Correct answer.
  4. Increasing the object-to-image receptor distance

Explanation

Geometric unsharpness is reduced by a smaller focal spot, a longer source-to-image receptor distance, and a shorter object-to-image receptor distance. Of the listed choices, only using a smaller focal spot directly reduces the penumbra.

Question 41Professional Ability – Radiography and Medical Imaging

When all other exposure factors are held constant, which factor primarily controls the brightness (density) of a digital radiograph?

  1. Kilovoltage peak selection
  2. Grid ratio selection
  3. Milliampere-seconds (mAs) Correct answer.
  4. Focal spot size selection

Explanation

Milliampere-seconds controls the quantity of X-ray photons reaching the image receptor, which determines receptor exposure and the displayed brightness of the radiograph. Kilovoltage mainly affects penetration and contrast, while focal spot size and grid ratio influence sharpness and scatter rather than primary brightness.

Question 42Professional Ability – Radiography and Medical Imaging

Which routine radiographic projections are standard for a wrist examination?

  1. AP oblique and tangential
  2. PA, lateral, and oblique Correct answer.
  3. PA and axial
  4. AP and lateral only

Explanation

A routine wrist series includes a PA projection, a lateral projection, and an oblique projection to show the carpal bones and joint spaces in different planes. AP and axial or tangential views are not standard wrist projections because they increase overlap or are used for other joints.

Question 43Professional Ability – Radiography and Medical Imaging

Which projection best demonstrates the patellofemoral joint space?

  1. Tangential sunrise view Correct answer.
  2. Standard lateral knee projection
  3. Standard AP knee projection
  4. PA oblique knee projection

Explanation

The tangential, or sunrise, projection directs the X-ray beam parallel to the patellofemoral joint space with the knee flexed, opening the joint for evaluation. AP, lateral, and oblique knee projections do not profile the patellofemoral articulation as clearly.

Question 44Professional Ability – Radiography and Medical Imaging

When radiographing the scaphoid, which positioning modification best demonstrates the bone?

  1. Radial deviation of the wrist with fist clenched
  2. Clenching the fist during exposure
  3. Supinating the forearm 45 degrees
  4. Ulnar deviation with angled central ray Correct answer.

Explanation

Ulnar deviation extends the scaphoid and reduces superimposition over the distal radius, and angling the central ray helps project the scaphoid clear of adjacent structures. Radial deviation tends to foreshorten the scaphoid and increase overlap.

Question 45Professional Ability – Radiography and Medical Imaging

In computed radiography, why is the photostimulable phosphor plate run through an erasure cycle before reuse?

  1. To recalibrate the laser scanning optics
  2. To cool the plate after laser stimulation
  3. To remove residual latent image Correct answer.
  4. To increase sensitivity of the phosphor layer

Explanation

The erasure cycle exposes the plate to bright light to release trapped electrons and clear any residual latent image from the previous exposure. Reusing a plate without erasure can produce ghosting or unwanted signal on the next image.

Question 46Professional Ability – Radiography and Medical Imaging

Which display parameter increases radiographic contrast without changing the raw image data?

  1. Window level manipulation
  2. Rescaling algorithm
  3. Edge enhancement filter
  4. Window width adjustment Correct answer.

Explanation

Narrowing the window width maps a smaller range of pixel values to the available gray scale, increasing displayed contrast while leaving the raw data unchanged. Window level mainly adjusts brightness, and edge enhancement affects sharpness rather than contrast mapping.

Question 47Professional Ability – Radiography and Medical Imaging

A supine patient is suspected of having a small pneumoperitoneum. Which additional projection is most appropriate?

  1. Supine lateral abdomen projection
  2. Prone PA abdomen projection
  3. Erect AP abdomen projection
  4. Left lateral decubitus Correct answer.

Explanation

A left lateral decubitus projection allows free intraperitoneal gas to rise above the liver and lateral abdominal wall, making small amounts of pneumoperitoneum easier to detect. Supine and prone projections may not show small free air collections because gas does not rise to a dependent or nondependent surface in the same way.

Question 48Professional Ability – Radiography and Medical Imaging

What is the primary risk of applying excessive edge enhancement to a digital chest radiograph?

  1. Pseudolesions and amplified noise Correct answer.
  2. Reduction of low-contrast soft-tissue detail
  3. Generalized loss of spatial resolution
  4. A measurable increase in patient dose

Explanation

Excessive edge enhancement exaggerates high-frequency differences and can amplify noise, creating pseudolesions or making normal structures appear abnormal. It does not improve true spatial resolution and may degrade diagnostic confidence.

Question 49Professional Ability – Radiography and Medical Imaging

A radiographer uses an air-gap technique instead of a grid for a lateral lumbar spine. What is the main image-quality disadvantage?

  1. Increased grid cutoff
  2. Decreased receptor exposure
  3. Increased scatter reaching the image receptor
  4. Increased magnification of the anatomy Correct answer.

Explanation

Air-gap technique increases the object-to-image receptor distance so scatter diverges away from the receptor, but it also magnifies the anatomy and can reduce sharpness. Grid cutoff is not relevant because no grid is used.

Question 50Professional Ability – Radiography and Medical Imaging

Which CT window setting is appropriate for evaluating lung parenchyma?

  1. Wide lung window Correct answer.
  2. Bone window
  3. Brain window
  4. Narrow soft-tissue window

Explanation

A wide lung window, such as width 1500 and level -600, displays the low-density lung parenchyma with sufficient gray-scale range to show fine vessels and interstitial detail. Soft-tissue, bone, and brain windows are too narrow or centered at the wrong attenuation values for lung evaluation.