PA chest (erect)

Patient position

• Erect, facing the IR, chin raised and resting on top of the IR holder.
• Feet slightly apart, weight even on both feet; MSP centred and perpendicular to the IR.
• Backs of the hands on the hips (or hug the IR); shoulders rolled forward and pressed down to move the scapulae off the lungs.
• Thorax not rotated; top of the IR about 5 cm (2″) above the shoulders.

Centering

MSP at the level of T7: 18–20 cm (7–8″) below the vertebra prominens, about the inferior angle of the scapulae.

Central ray

Perpendicular to the IR, horizontal.

Source-to-image distance

180 cm (72″): keeps heart magnification to a minimum.

Image evaluation

• 10 posterior ribs above the diaphragm (≥ 9 acceptable)
• Sternal ends of the clavicles equidistant from the spinous processes
• Scapulae projected outside the lung fields
• Both apices and both costophrenic angles included
• Thoracic vertebrae faintly seen through the heart shadow