X-ray of the lungs: interpretation

What is it about ?

Radiography is a technique that allows you to get images of certain tissues in the body. It uses X-rays to produce images of a part of the body, for example the chest (thorax). Some tissues in the body allow x-rays to pass, others do not. The bones of the thorax are thus visualized, as well as the organs it contains, and the doctor can observe any abnormalities.

What can the doctor see on an x-ray of the lungs?

It is not easy to interpret an x-ray. Sometimes the image may appear normal at first glance, but an abnormality may be hidden, for example behind the heart. Therefore, a specialist (radiologist) will examine the x-ray and prepare a report (protocol). In addition, he will always compare the image with any previous examinations. Changes in images can be important.

On an x-ray of the lungs, the radiologist may see the following:

  • Inflammations:
    In case of bronchitis, the x-ray is normal. In pneumonia, one or more denser parts can be seen, and sometimes lines. The tuberculosis is usually seen in the tops of the lungs (apex).
  • Atelectasis:
    A collapsed part of a lung that is no longer receiving air.
  • Lung cancer :
    The results of the x-ray can be very variable. Most often, thickening of the lung tissue is observed in the form of a white ball. Sometimes the only abnormality is atelectasis, sometimes there is an enlargement of the tissue visible behind the breastbone, or there is fluid between the envelopes around the lungs (pleura). The x-ray may be normal if the tumor is small, located in the windpipe, or hidden behind the breastbone or diaphragm.
  • Metastases in the lungs:
    The lungs are the site of metastasis from a tumor located elsewhere in the body. The most typical images are round spots or denser parts in the lung tissue.
  • Sarcoidosis :
    It is a systemic disease in which several organs or tissues are involved in an inflammatory process. The first phase is characterized by symmetrical swelling of the lymph nodes located around the left and right main bronchi.
  • Hodgkin’s disease and other lymphomas :
    The space between the two lungs seems wider.
  • Heart failure :
    The heart is dilated, and its shadow on the x-ray is enlarged.
  • Presence of fluid between the envelopes surrounding the lungs (pleura):
    This can occur among others in cancer,heart failure
  • Benign lesions of the pleura:
    In this case, adhesions and / or plaques are visible. The doctor will take into account any lesions due to asbestos exposure.
  • Pneumothorax :
    Through a breach in the pleura, air can enter between the chest wall and the lung. This causes the lung to collapse.
  • Pulmonary embolism :
    A blood clot is blocking a pulmonary artery. It is often very difficult to see on a chest x-ray, and any abnormalities are often atypical.

What can you do ?

For the x-ray, the chest must be completely exposed, i.e. without a bra or jewelry, etc.
If you are (possibly) pregnant, tell the doctor. No x-ray will be done unless it is strictly necessary at that time.

Want to know more?


Foreign clinical practice guide ‘Interpretation of chest radiography’ (2000), updated on 11.09.2017 and adapted to the Belgian context on 09.02.2020 – ebpracticenet