CXR

Chest X-ray (CXR) is a type of radiography used primarily to evaluate the lungs, heart, and chest wall. A CXR is one of the most common imaging tests performed in clinical practice. It can help diagnose conditions like pneumonia, heart failure, pulmonary edema, and lung cancer, among others. The procedure involves exposing the chest briefly to a small amount of ionizing radiation to produce images of the chest's interior.

Indications

Chest X-rays are indicated for a variety of symptoms and conditions, including but not limited to:

• Shortness of breath
• Persistent cough
• Chest pain
• Fever of unknown origin
• Monitoring progression or resolution of diseases, such as pneumonia
• Pre-operative evaluation
• Evaluation of known or suspected pulmonary diseases
• Assessment of cardiac silhouette for possible cardiac enlargement

Procedure

During a chest X-ray, the patient is positioned in front of an X-ray machine and asked to hold a deep breath. This helps to spread the lungs out and provides a clearer picture. The X-ray beams pass through the chest and are captured on a digital detector or photographic film placed on the opposite side. The amount of radiation exposure from a typical chest X-ray is low and considered safe for most individuals, but it is generally avoided in pregnant women due to potential risks to the fetus.

Types of Chest X-rays

There are two primary views in chest radiography:

• Posteroanterior (PA) view: The X-ray beams pass from back-to-front. It is the standard view and provides the best image quality.
• Lateral view: The beams pass from one side of the chest to the other. This view is often used in conjunction with the PA view to better visualize certain structures of the chest.

Interpretation

Interpretation of a chest X-ray involves assessing various components, including:

• The lungs: for signs of infections, chronic obstructive pulmonary disease (COPD), or cancer.
• The heart: to evaluate its size and shape, which can indicate heart failure or other cardiac conditions.
• The bones: checking for fractures or abnormalities.
• The diaphragm: for signs of elevation, hernia, or free air.
• The pleura: for pleural effusions or thickening.

Limitations

While chest X-rays are invaluable diagnostic tools, they have limitations. Some conditions may not be visible, or findings may be nonspecific and require further testing with more advanced imaging techniques, such as CT scans or MRIs. Additionally, the interpretation of CXRs requires significant expertise and experience.

Safety

The radiation dose from a chest X-ray is considered low, equivalent to a few days' worth of natural background radiation. However, repeated exposure, particularly in short intervals, should be avoided when possible. Protective measures, such as lead aprons, are used when necessary, especially to protect sensitive areas like the thyroid gland and reproductive organs.