Radiography Flashcards

Which radiation protection principle involves limiting exposure to only what is needed for diagnosis?

Answer: ALARA

ALARA (As Low As Reasonably Achievable) is the guiding principle of radiation protection that mandates minimizing patient and occupational dose.

On a PA chest radiograph, the carina should normally be located at which vertebral level?

Answer: T4-T5

The carina (tracheal bifurcation) is normally located at the level of T4-T5 on a PA chest radiograph.

What type of film/screen combination is used to reduce patient dose while maintaining image quality?

Answer: Fast-speed, rare earth screens

Rare earth fast-speed screens require less radiation to produce adequate density, significantly reducing patient dose compared to calcium tungstate systems.

Which positioning error causes the trachea to appear shifted to the left on a PA chest radiograph?

Answer: Patient rotated with right side closer to detector

When the patient is rotated with the right side closer to the detector, the right sternoclavicular joint appears larger and the trachea can appear shifted to the left.

The term 'OID' in radiography stands for what?

Answer: Object-Image Distance

OID (Object-Image Distance) is the distance between the object being radiographed and the image receptor, which affects magnification and recorded detail.

Which chest pathology would appear radiopaque (white) on a PA chest radiograph?

Answer: Pleural effusion

Pleural effusion accumulates fluid in the pleural space, which attenuates x-rays and appears as a white (radiopaque) opacity on the radiograph.

What is the primary advantage of digital radiography (DR) over computed radiography (CR)?

Answer: Immediate image acquisition without plate processing

DR systems capture images directly without the intermediate step of processing an imaging plate, providing immediate image display and improved workflow efficiency.