Chest X-ray

General Description

A chest X-ray is a diagnostic test that applies X-rays or other ionizing materials to obtain images of the bones, organs, and tissues of the chest, including the ribs, spine, heart, lungs, pleura, airways, diaphragm, and major blood vessels.

When X-rays pass through tissues, they are absorbed in varying amounts depending on the density of each tissue (the denser the tissue, the more radiation it absorbs). The absorption level is reflected in different shades displayed in the image:

• The ribs and vertebrae, being bones, are denser and appear white.
• The heart, a muscle, appears in grayish tones.
• The lungs, which contain air, appear darker because gas is radiolucent and does not absorb radiation.

When is it indicated?

A chest X-ray can be used to examine the morphology and condition of thoracic structures and organs, helping to detect various abnormalities or conditions, such as:

• Lung problems, including infections, pneumonia, air or fluid accumulation, emphysema, fibrosis, cysts, nodules, tumors, or cancer.
• Cardiac disorders, such as heart failure, valvular problems, or fluid accumulation around the heart.
• Fractures and other bone issues in the ribs or spine.
• Calcifications in the heart or blood vessels.
• Diaphragmatic hernias.
• Vascular problems, such as aortic aneurysms.
• Tissue changes after experiencing a disease, undergoing treatment, or having surgery in the area.

A chest X-ray is commonly requested when a patient presents with:

• Chest pain.
• Difficulty breathing.
• Trauma to the area.
• Severe or persistent cough.

How is it performed?

To perform the X-ray, the patient must stand between the X-ray machine and a plate or film sensitive to radiation. When the X-ray beams pass through body tissues, they are recorded as an image on the plate. However, modern equipment uses digital sensors instead of film: these sensors convert the absorbed radiation into electrical signals and immediately record the image in digital format, offering higher image quality.

During the examination, different views or projections of the chest are taken, typically a posteroanterior view (where radiation passes through the back) and a lateral view. If the patient cannot stand due to mobility difficulties or the need to remain in bed, the examination may be performed with an anteroposterior view (where radiation passes through the front) while the patient is seated or lying on their back.

Risks

A chest X-ray involves exposure to radiation, which is associated with a potential risk of developing cancer. However, the amount of radiation received is minimal, even lower than the radiation naturally present in the environment. A standard adult chest X-ray exposes the patient to a dose of 0.1 mSv, equivalent to nearly 10 days of natural background radiation. Therefore, in general, X-rays do not pose a real risk or cause side effects for the patient.

Moreover, modern X-ray systems minimize scattered radiation by using controlled beams and protective measures for areas not being examined, such as lead aprons. In the case of pregnant women, where there is a risk of fetal harm, the test is only performed if absolutely necessary and always with strict protective measures.

What to expect from a chest X-ray

After removing clothing and metal objects, the patient puts on a gown provided by the medical facility. For the posteroanterior view, the patient must press their chest against the imaging plate with their hands on their hips. They are instructed to take a deep breath and hold it while the X-rays are applied, as this helps achieve a clearer view of the heart and lungs. Additionally, remaining still during the X-ray is crucial to prevent the image from becoming blurry.

For the lateral projection, the patient places one shoulder against the plate and raises their hands above their head while taking another deep breath and holding it. During the procedure, the specialist stands behind a wall or in an adjacent room to activate the X-ray machine and protect themselves from radiation.

The X-ray itself is painless, and the patient does not feel anything other than the possible discomfort of maintaining certain postures. The application of X-rays lasts only a few seconds, and the entire procedure typically takes no more than 15 minutes. It is an outpatient test, meaning that once it is completed, the patient can resume their daily routine without needing rest or special care.

Medical specialties that request chest X-rays

The specialties that commonly use chest X-rays for diagnosis or monitoring include primary care, emergency medicine, pulmonology, cardiology, and traumatology. This test is performed in the radiology department.