Chest X-ray

If lung pathology is suspected, a chest X-ray should be performed initially before requesting other imaging. However, if the patient is acutely unwell and haemodynamically unstable, arrange transfer to hospital for investigation.

Note: If lung pathology is suspected, a chest X-ray should be performed initially before requesting other imaging.

The dose of radiation from chest X-ray is very low—0.02 to 0.1 mSv depending on the number of views taken (eg just posterior–anterior [PA] or also with a lateral view). This dose is equivalent to 4 to 18 days of background radiation. See Radiation exposure in thoracic imaging for more information.

For assessment in primary care, a chest X-ray can:

distinguish pneumonia from bronchitis
diagnose important causes of breathlessness (eg pneumothorax, pleural effusion, pneumonia, cardiac failure)
suggest advanced interstitial lung disease or lung masses in a patient presenting with symptoms; a CT scan should be ordered to further investigate these conditions.

Compare chest X-rays to previous X-rays if possible. A follow-up chest X-ray may be done at an appropriate interval depending on the possible pathology (eg to confirm pneumonia resolution, particularly in a smoker).