ARRT Radiography Practice Questions 2026: 8 Items Explained

Answer: A — It roughly doubles

By the 15% rule, raising kVp by about 15% roughly doubles receptor exposure, the same effect as doubling the mAs. Going from 70 to 80 kVp is an increase of about 14%, so exposure approximately doubles.

• B. kVp affects both the number and the penetrating ability of photons reaching the receptor, so changing it with mAs fixed does change exposure.
• C. Halving exposure would need a 15% decrease in kVp (about 70 to 60), not an increase.
• D. The 15% figure is the change in kVp; the resulting change in receptor exposure is about 100%, not 15%.

Answer: A — Telling the patient that the image shows a fracture

Interpreting images and communicating a diagnosis is the role of the radiologist or ordering provider. A radiographer who tells a patient a fracture is present is making a diagnosis, which is outside the ASRT Practice Standards and can breach the ARRT Standards of Ethics.

• B. Using two identifiers (such as name and date of birth) is a required safety step the technologist performs on every exam.
• C. Collimation is a core radiographer responsibility and one of the main ways to keep patient dose as low as reasonably achievable.
• D. Patient education about the procedure and aftercare is part of the radiographer's role.

Answer: D — Reassure the patient and keep monitoring closely

Transient warmth, flushing, metallic taste and limited nausea are mild physiologic reactions to contrast, not allergic-like ones. The ACR Manual on Contrast Media says observation and reassurance are usually all that is needed, while staying alert for any progression.

• A. Epinephrine is for moderate or severe allergic-like reactions such as diffuse hives with bronchospasm or anaphylaxis; giving it here is not indicated and carries risk.
• B. A rapid response is for a deteriorating patient; stable vital signs with mild physiologic symptoms do not meet that bar.
• C. IV access should be kept in place during and after a contrast reaction so drugs can be given if the reaction progresses.

Answer: B — Perform a cervicothoracic (swimmer's) lateral

The evaluation criteria for a lateral cervical spine require C7-T1 to be shown. When the shoulders block it, the cervicothoracic (Twining or swimmer's) lateral raises one arm and depresses the other shoulder to move the humeral heads off the junction.

• A. Collimation reduces scatter but cannot move the shoulders out of the way of C7-T1.
• C. Lowering kVp reduces penetration through the dense shoulder region and makes the problem worse.
• D. More mAs may darken the area but does not separate the shoulders from the vertebrae; it only adds dose to a repeat that will still fail the criteria.

Answer: C — The patient was rotated from a true lateral

In a true lateral the posterior vertebral body margins superimpose and the intervertebral foramina are open. A double posterior border with closed foramina is the classic sign of rotation; the fix is to make the shoulders and hips perpendicular to the image receptor.

• A. A longer SID reduces magnification and distortion; it does not create double vertebral margins.
• B. Unwanted CR angle tilts the end plates so the disk spaces close, but it does not cause the posterior margins to separate front-to-back the way rotation does.
• D. A short exposure time reduces motion blur; it has no effect on how the vertebrae are superimposed.

Answer: B — Higher dose, because more mAs is needed

A higher-ratio grid absorbs more radiation (scatter and some primary), so it has a higher grid conversion (Bucky) factor. To keep receptor exposure the same the technologist must raise mAs, which raises patient dose. Use the lowest grid ratio that gives acceptable image quality.

• A. Removing more scatter improves contrast, but it does not lower patient dose; the extra mAs needed raises it.
• C. Grids do change dose: whatever the grid absorbs has to be made up with more technique.
• D. The usual compensation for a grid is mAs, not kVp; the dose increase comes from the mAs increase.

Answer: C — Pixel size too large (sampling frequency too low) for the detail

Each pixel displays one value, so a diagonal edge is drawn as a series of square steps. When pixels are large relative to the detail (low sampling frequency), the steps become visible on magnification. Smaller pixels, a larger matrix for the same field of view, improve spatial resolution.

• A. Window level changes image brightness; it does not change the size of the picture elements.
• B. Bit depth sets how many gray shades each pixel can show (contrast resolution); more bit depth does not create jagged edges.
• D. Heavy smoothing blurs edges and makes them softer, the opposite of a sharp stair-step pattern.

Answer: C — It is higher, because barium has a much higher atomic number

The probability of a photoelectric interaction rises steeply with atomic number, roughly as Z cubed, and falls with photon energy. Barium (Z = 56) absorbs far more photons than soft tissue (effective Z about 7.4), which is why it appears radiopaque and why contrast agents are made from high-Z elements.

• A. mAs sets how many photons there are, not the probability that each one is absorbed; photoelectric interaction depends on Z and photon energy.
• B. Barium is a dense, high-Z material; it increases, not reduces, electron density and absorption.
• D. Photon energy is set by the kVp, which is fixed; the absorber cannot raise it, and higher energy would actually lower photoelectric probability.