Patient Positioning & Procedures Flashcards

The Waters projection (PA axial) is most commonly used to demonstrate which anatomical structures?

Answer: Maxillary sinuses

The Waters projection is the method of choice for demonstrating the maxillary sinuses by projecting the petrous ridges below the sinus floors.

For a lateral projection of the cervical spine, how should the patient's shoulders be positioned?

Answer: Depressed as far as possible (pulled down)

Depressing the shoulders as far as possible pulls them out of the field of view to visualize the lower cervical vertebrae (C6–C7).

What is the correct SID (source-to-image distance) for routine chest radiography?

Answer: 72 inches (180 cm)

A 72-inch (180 cm) SID is standard for chest radiography to minimize cardiac magnification and improve image sharpness.

Which decubitus position would be used to demonstrate a possible left-sided pleural effusion?

Answer: Right lateral decubitus (lying on right side)

Right lateral decubitus (patient lying on the right side) allows a left-sided pleural effusion to layer dependently along the left lateral chest wall.

For an AP projection of the ankle, where is the central ray directed?

Answer: Midpoint between the malleoli (ankle mortise)

The central ray for an AP ankle is directed perpendicular to the midpoint between the malleoli, which is the ankle joint.

What is the purpose of using a wedge filter when imaging the foot in a lateral projection?

Answer: To compensate for the varying thickness of the foot and produce more uniform density

A wedge compensating filter equalizes the density differences between the thick heel and thin toe areas, producing a more uniform lateral foot image.