Chest x-ray positioning: Is PA projection alone sufficient?

Should we always use a posteroanterior (PA) and lateral chest x-ray during the diagnostic workup of patients with respiratory signs and symptoms, or is the PA projection alone sufficient in some instances?

Julian Dobranowski, MD: In general, I think any patient who requires a chest x-ray should have a PA and lateral if they are physically able to have the examination. The lateral film offers incredible information that you cannot derive from the PA examination alone. For any patient with initial symptoms, it is mandatory to have a PA and lateral chest x-ray.

There are situations—for example, a patient with a pneumothorax—when you would not require the lateral every time you do the examination. I think once you have the initial diagnosis, follow-up examinations can be tailored. You can eliminate the lateral. But for any initial workup it is required.