Written by Dimitrios Vrachatis, Specialist Cardiologist, PhD, National and Kapodistrian University of Athens.
What is a chest X-ray?
This examination uses a small dose of ionising radiation to record the structures of the chest — more precisely, their shadows — on special film or, nowadays, a suitable digital medium.
How is it performed?
A chest X-ray is a non-invasive examination performed with specialised equipment in a radiology department. X-rays, a type of electromagnetic radiation, pass through the area being examined and record its shadow.
You stand still in front of the machine in the position indicated by the radiographer and take a deep breath as instructed. The examination is completed within a few minutes.
The chest is usually examined in two perpendicular views: a posteroanterior view and a lateral view.
Metal objects, such as necklaces or other jewellery, must be removed so that their shadows do not obscure body structures.
What does it show?
It produces a two-dimensional image of the chest, lungs, heart and major blood vessels — in simple terms, a picture of the heart and lungs.
What does the cardiologist assess on a chest X-ray?
A chest X-ray provides information about:
- The size and shape of the heart.
- Fluid around the heart, in the pericardium.
- Fluid in the lungs.
- Air outside the lungs (pneumothorax).
- The integrity of the bones of the chest.
- Areas suspicious for infection or malignancy.
When might a cardiologist request this examination?
The cardiologist may request it when investigating shortness of breath, chest pain, cough or fever, or to assess pulmonary congestion in patients with heart failure. Findings are considered alongside the rest of the clinical and laboratory assessment, including physical examination, ECG and echocardiography.
What should I know before the examination?
Before any X-ray examination, tell your doctor if pregnancy is possible, as this is a relative contraindication. In that situation, the examination is performed only if it is absolutely necessary, there is no alternative method of investigation and the patient has been informed of the possible risks to the fetus.
Is the examination painful?
No. The only discomfort you may feel is the temperature difference when touching the imaging plate, which is usually cold.
Is any preparation required?
No. The examination is quick and straightforward and requires no special preparation.
Who interprets the result?
The formal interpretation of a chest X-ray belongs to the medical specialty of radiology. Most clinicians are nevertheless familiar with assessing it.
Does it provide detailed information?
A chest X-ray is one of the oldest and most widely used imaging examinations. It is quick and relatively inexpensive. However, it provides only general information about health, and suspected abnormalities often require further clinical assessment and tests.
It also exposes the body to ionising radiation, although at a low dose. It should therefore be performed for a clinical indication rather than as a routine formality in a check-up.