Computed Tomography (CT) of the Chest

A computed tomography (CT) scan of the chest is a non-invasive medical imaging test used to produce detailed cross-sectional images of the lungs, heart, esophagus, and other structures in the chest cavity.

Indications

• Evaluation of lung nodules or masses
• Assessment of lung diseases such as pneumonia, bronchiectasis, or interstitial lung disease
• Diagnosis and staging of lung cancer
• Evaluation of the heart and its blood vessels, including coronary artery disease
• Assessment of the esophagus and mediastinum (the area between the lungs)
• Guidance for biopsies or other interventional procedures

Procedure

The CT scan is typically performed in a hospital or outpatient imaging center. The patient lies on a table that slides into a large, doughnut-shaped machine called a gantry. The scanner uses X-rays and computer technology to produce images of the chest.

The procedure usually involves the following steps:

1. The patient removes any clothing or jewelry that may interfere with the scan
2. The patient lies on the table and is positioned by the technologist
3. The table slides into the gantry, and the scanner begins to rotate around the patient
4. X-rays are used to produce images of the chest, which are then reconstructed into cross-sectional images by a computer
5. The patient may be asked to hold their breath for a few seconds during the scan to ensure clear images
6. The scan typically takes between 10-30 minutes to complete

Types of Chest CT Scans

There are several types of chest CT scans, including:

• Non-contrast CT scan: This type of scan does not use contrast material (dye) and is often used to evaluate lung diseases or detect lung nodules.
• Contrast-enhanced CT scan: This type of scan uses contrast material to highlight blood vessels, organs, or other structures in the chest. It is often used to evaluate vascular diseases, such as coronary artery disease, or to guide biopsies.
• High-resolution CT (HRCT) scan: This type of scan uses a special technique to produce highly detailed images of the lungs and is often used to evaluate interstitial lung disease.

Risks and Complications

While CT scans are generally safe, there are some potential risks and complications to consider:

• Radiation exposure: CT scans use X-rays, which involve radiation exposure. However, the benefits of the scan typically outweigh the risks.
• Allergic reactions to contrast material: Some patients may be allergic to the contrast material used in CT scans. Symptoms can range from mild (hives, itching) to severe (anaphylaxis).
• Kidney damage: The contrast material used in CT scans can cause kidney damage in some patients, particularly those with pre-existing kidney disease.

Preparation

To prepare for a chest CT scan:

• Avoid eating or drinking for several hours before the scan (if contrast material is used)
• Remove any clothing or jewelry that may interfere with the scan
• Inform the technologist of any allergies, medical conditions, or previous reactions to contrast material
• Follow any specific instructions provided by the doctor or technologist

Results

The results of a chest CT scan are typically interpreted by a radiologist and reported to the referring doctor. The report may include information about:

• The presence or absence of lung nodules or masses
• The extent of lung disease (e.g., pneumonia, interstitial lung disease)
• The presence or absence of coronary artery disease
• Any other abnormalities detected in the chest cavity