Chest Left Lateral is a radiography positioning projection of the Chest. Upright left lateral chest. Complement to PA. SID 72". The centering point is located mid-thorax at t7 level. cr enters at the patient’s right side and exits left, perpendicular to the ir.. The central ray is horizontal, perpendicular to ir. centered to t7 in mid-coronal plane.. Image-quality criteria include both costophrenic angles included., posterior ribs superimposed (no rotation between left and right hemithorax).. Standard exposure ranges from 110 to 125 kVp, 4 to 10 mAs, at an SID of 72 inches (180 cm).
Patient preparation
- Verify patient identity using two identifiers.
- Remove radiopaque objects from the chest area.
- Position patient erect, left lateral against the upright Bucky.
- Raise arms above head, hands on opposite elbows, to clear the lung fields.
- Chin raised to clear the apex; instruct full inspiration and hold.
Position & centering point
Mid-thorax at T7 level. CR enters at the patient’s right side and exits left, perpendicular to the IR.
Central ray
Horizontal, perpendicular to IR. Centered to T7 in mid-coronal plane.
Exposure / technique
- kVp
- 110–125
- mAs
- 4–10
- SID
- 72" (180 cm)
- Notes
- mAs ~2x the PA, lateral chest is thicker. Same high-kVp technique to penetrate the mediastinum.
Image-quality criteria
- Both costophrenic angles included.
- Posterior ribs superimposed (no rotation between left and right hemithorax).
- Sternum in profile, no rotation.
- Heart shadow over the spine; lung fields anterior to the heart should be clear.
- Hilar region clearly seen anterior to the thoracic spine.
- No motion blur, sharp diaphragm and vascular markings.
Clinical indications
- Always paired with PA chest unless the patient cannot tolerate.
- Localization of lesions seen on PA (e.g., is the nodule anterior or posterior?).
- Evaluation of retrocardiac and retrosternal spaces.
- Posterior costophrenic angle assessment (small effusions show here first).
Aligned to the 2025 ARRT Content Specifications.