ARRT Radiography Flashcards

A grid with a ratio of 12:1 compared to an 8:1 grid will:

Answer: Remove more scatter radiation but require more mAs

Higher ratio grids remove more scatter (improving contrast) but transmit less primary radiation, requiring increased mAs to maintain density.

Which of the following changes will DECREASE quantum noise (mottle) on a digital radiograph?

Answer: Increasing mAs

Increasing mAs delivers more photons to the detector, reducing statistical noise (quantum mottle) and producing a smoother image.

For a lateral projection of the cervical spine, the central ray is directed to:

Answer: C4

The central ray is directed horizontally to the level of C4 (the most prominent cervical vertebra) for the lateral cervical spine.

What is the primary advantage of using a high-frequency generator over a single-phase generator?

Answer: More consistent, nearly constant potential with less voltage ripple

High-frequency generators produce nearly constant potential (less than 1% ripple), resulting in a more efficient and consistent x-ray beam.

A patient is positioned prone with the head turned to one side. A horizontal central ray is directed to the level of ASIS. This describes which projection?

Answer: Ventral decubitus abdomen

The prone (ventral decubitus) position with a horizontal beam is used for cross-table lateral or decubitus abdominal studies to demonstrate air-fluid levels.

Which of the following best describes the heel effect (anode heel effect)?

Answer: Lower x-ray intensity on the anode side of the beam

The anode heel effect causes x-ray intensity to be lower on the anode side due to photon absorption within the anode itself.

Which radiographic sign on a chest x-ray indicates that the endotracheal tube is positioned too low?

Answer: Right mainstem bronchus intubation with left lung atelectasis

An ET tube advanced too far typically enters the right mainstem bronchus, ventilating only the right lung and causing left lung collapse.