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Alternative names
Thoracic CT; CT scan - lungs; CT scan - chest
Definition
Chest CT is a computed tomography scan of the chest and upper abdomen.
How the test is performed
You will be asked to lie on a narrow table (gantry) that slides into the center of the scanner. Depending on what is being scanned, you may lie on the stomach, back, or side.
As with standard photography, if you move while the CT image is being taken, it will blur. Because of this, the operator of the scanner will tell you when to hold your breath and not move.
As the exam takes place, the gantry will advance small intervals through the scanner. Modern spiral scanners can perform the examination in one continuous motion of the gantry. Generally, complete scans will only take a few minutes.
How to prepare for the test
The CT scanner has a weight limit to prevent damage to the mechanized gantry. Have the health care provider contact the scanner operator if you weigh more than 300 pounds.
Metal interferes with the x-rays, so you may be asked to remove jewelry and wear a hospital gown during the study.
How the test will feel
The x-rays are painless. The primary discomfort may be from the need to lie still on the table.
Why the test is performed
Chest CT is used to exam the structures inside the chest. It is noninvasive and poses less risk than invasive procedures (such as angiography or exploratory surgery).
Common indications for chest CT include:
- When there is a chest injury
- When a tumor or mass (clump of cells) is suspected
- To determine the size, shape, and position of internal organs
- To look for bleeding or fluid collections in the lungs or other areas
What abnormal results mean
Chest CT may show many disorders of the heart, lungs, or chest area, including:
- Enlarged lymph nodes (lymphadenopathy)
- Abnormalities of the structure or position of the heart, lungs, or blood vessels
- Bronchiectasis
- Tumors, nodules, or cysts within the chest
- The stage of some lung tumors or esophageal cancer
- Aortic aneurysm (thoracic)
- Pleural effusion
- Pneumonia
- Accumulations of blood or fluid
What the risks are
CT scans and other x-rays are regulated to provide the minimum amount of radiation exposure needed to produce the image. During pregnancy, a chest CT scan is not recommended unless the benefits outweigh the risk of radiation exposure to the fetus. CT scans provide low levels of radiation.
Special considerations
The benefits of a CT scan usually far outweigh the risks. A CT scan is one of the best ways of looking at soft tissues such as the heart and lungs. |
