Left lateral chest (erect)

Patient position

• Erect, left side against the IR (left lateral puts the heart nearest the IR) unless the right side is of interest.
• Both arms raised above the head, holding the opposite elbows; chin up.
• MSP parallel to the IR, MCP vertical: no rotation and no leaning.
• Weight even on both feet; top of the IR about 5 cm above the shoulders.

Centering

Midcoronal plane at the level of T7 (8–10 cm below the jugular notch).

Central ray

Perpendicular to the IR, horizontal.

Source-to-image distance

180 cm (72″).

Image evaluation

• Posterior ribs superimposed: ≤ 1 cm apart (divergence only)
• Arms and chin clear of the apices
• Intervertebral foramina of the T-spine open
• Sternum in profile; both costophrenic angles included