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Chest CT
Thoracic CT; CT scan - lungs; CT scan - chest
A chest CT (computed tomography) scan is an imaging method that uses x-rays to create cross-sectional pictures of the chest and upper abdomen.
How the Test is Performed
The test is done in the following way:
- You'll likely be asked to change into a hospital gown.
- You lie on a narrow table that slides into the center of the scanner. Once you are inside the scanner, the machine's x-ray beam rotates around you.
- You must be still during the exam, because movement causes blurred images. You may be told to hold your breath for short period of time.
The complete scan takes 30 seconds to a few minutes.
Certain CT scans require a special dye, called contrast, to be delivered into the body before the test starts. Contrast highlights specific areas inside the body and creates a clearer image. If your doctor requests a CT scan with intravenous contrast, you will be given it through a vein (IV) in your arm or hand. A blood test to measure your kidney function may be done before the test. This test is to make sure your kidneys are healthy enough to filter the contrast.
CT scans
A computed tomography (CT) scan is an imaging method that uses x-rays to create pictures of cross-sections of the body. Related tests include:Abdomin...
You may be given medicine to help you relax during the test.
How to Prepare for the Test
Some people have allergies to IV contrast and may need to take medicine before their test to safely receive this substance.
Contrast can be given in several ways, depending on the type of CT being performed.
- It may be delivered through a vein (IV) in your hand or forearm.
- It may be given through the rectum using an enema.
- You might drink the contrast before your scan. When you actually drink the contrast depends on the type of exam being done. The contrast liquid may taste chalky, although some are flavored to make them taste a little better. The contrast eventually passes out of your body through your stool.
If contrast is used, you may also be asked not to eat or drink anything for 4 to 6 hours before the test.
If you weigh more than 300 pounds (135 kilograms), have your health care provider contact the scanner operator before the exam. CT scanners have a weight limit. Too much weight can damage the scanner's working parts.
Because it is hard for x-rays to pass through metal, you will be asked to remove jewelry.
How the Test will Feel
Some people may have discomfort from lying on the hard table.
Contrast given through an IV may cause a slight burning sensation, a metallic taste in the mouth, and a warm flushing of the body. These sensations are normal and usually go away within a few seconds.
There is no recovery time, unless you were given medicine to relax. After a CT scan, you can go back to your normal diet, activity, and medicines.
Why the Test is Performed
CT quickly creates detailed pictures of the body. The test may be used to get a better view of the structures inside the chest. A CT scan is one of the best ways of looking at soft tissues such as the heart and lungs.
A chest CT may be done:
- After a chest injury
-
When a
tumor
or mass (clump of cells) is suspected, including a solitary pulmonary nodule seen on a chest x-ray
Tumor
A tumor is an abnormal growth of body tissue. Tumors can be cancerous (malignant) or noncancerous (benign).
Read Article Now Book Mark Article - To determine the size, shape, and position of organs in the chest and upper abdomen
- To look for bleeding or fluid collections in the lungs or other areas
- To look for infection or inflammation in the chest
- To look for blood clots in the lungs
-
To look for scarring in the lungs
What Abnormal Results Mean
Thoracic CT may show many disorders of the heart, lungs, or chest area, including:
-
A
tear in the wall
, an
abnormal widening or ballooning
, or
narrowing
of the major artery carrying blood out of the heart (aorta)
Tear in the wall
Aortic dissection is a serious condition in which there is a tear in the wall of the major artery carrying blood out of the heart (aorta). As the te...
ImageRead Article Now Book Mark ArticleAbnormal widening or ballooning
An aneurysm is an abnormal widening or ballooning of a portion of an artery due to weakness in the wall of the blood vessel. A thoracic aortic aneury...
ImageRead Article Now Book Mark ArticleNarrowing
The aorta carries blood from the heart to the vessels that supply the body with blood. If part of the aorta is narrowed, it is hard for blood to pas...
ImageRead Article Now Book Mark Article - Other abnormal changes of the major blood vessels in the lungs or chest
-
Buildup of
blood or fluid around the heart
Blood or fluid around the heart
Cardiac tamponade is pressure on the heart that occurs when blood or fluid builds up in the space between the heart muscle and the outer covering sac...
ImageRead Article Now Book Mark Article -
Lung cancer or cancer that has spread to the lungs
from elsewhere in the body
Lung cancer or cancer that has spread t...
Lung metastases are cancerous tumors that start somewhere else in the body and spread to the lungs.
ImageRead Article Now Book Mark Article - Collection of fluid around the lungs (pleural effusion)
- Damage to, and widening of the large airways of the lungs (bronchiectasis)
- Enlarged lymph nodes
-
Lung disorders in which the
lung tissues become inflamed
and then damaged.
Lung tissues become inflamed
Interstitial lung disease is a group of lung disorders in which the lung tissues become inflamed and then damaged.
ImageRead Article Now Book Mark Article - Pneumonia
- Esophageal cancer
- Lymphoma in the chest
- Tumors, nodules, or cysts in the chest
Risks
CT scans and other x-rays are strictly monitored and controlled to make sure they use the least amount of radiation. CT scans use low levels of ionizing radiation, which has the potential to cause cancer and other defects. However, the risk from any one scan is small. The risk increases as many more studies are done.
In some cases, a CT scan may still be done if the benefits greatly outweigh the risks. For example, it can be more risky to not have the exam if your doctor thinks you might have cancer.
The most common type of contrast given into a vein contains iodine. If a person with an iodine allergy is given this type of contrast, nausea, sneezing, vomiting, itching, or hives may occur. In rare cases, the dye can cause a life-threatening allergic response called anaphylaxis. If you have any trouble breathing during the test, you should notify the scanner operator immediately. Scanners come with an intercom and speakers, so the operator can hear you at all times.
In people with kidney problems, the dye may have harmful effects on the kidneys. In these situations, special steps may be taken to make the contrast dye safer to use.
References
Gotway MB, Panse PM, Gruden JF, Elicker BM. Thoracic radiology. In: Broaddus VC, Mason RJ, Ernst JD, et al, eds. Murray and Nadel's Textbook of Respiratory Medicine . 6th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 18.
Shaw AS, Prokop M. Computed tomography. In: Adam A, Dixon AK, Gillard JH, Schaefer-Prokop CM, eds. Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging . 6th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2015:chap 4.
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CT scan - illustration
CT stands for computerized tomography. In this procedure, a thin X-ray beam is rotated around the area of the body to be visualized. Using very complicated mathematical processes called algorithms, the computer is able to generate a 3-D image of a section through the body. CT scans are very detailed and provide excellent information for the physician.
CT scan
illustration
-
Thyroid cancer - CT scan - illustration
This CT scan of the upper chest (thorax) shows a malignant thyroid tumor (cancer). The dark area around the trachea (marked by the white U-shaped tip of the respiratory tube) is an area where normal tissue has been eroded and died (necrosis) as a result of tumor growth.
Thyroid cancer - CT scan
illustration
-
Pulmonary nodule, solitary - CT scan - illustration
This CT scan shows a single lesion (pulmonary nodule) in the right lung. This nodule is seen as the light circle in the upper portion of the dark area on the left side of the picture. A normal lung would look completely black in a CT scan.
Pulmonary nodule, solitary - CT scan
illustration
-
Lung mass, right upper lobe - CT scan - illustration
This is a CT scan of the upper lungs. This individual has a mass in upper part of the right lung (left side of picture).
Lung mass, right upper lobe - CT scan
illustration
-
Bronchial cancer - CT scan - illustration
This chest CT scan shows a cross-section of a person with bronchial cancer. The two dark areas are the lungs. The light areas within the lungs represent the cancer.
Bronchial cancer - CT scan
illustration
-
Lung mass, right lung - CT scan - illustration
This is a CT scan of the upper chest showing a mass in the right lung (seen on the left side of the picture).
Lung mass, right lung - CT scan
illustration
-
Lung nodule, right lower lung - CT scan - illustration
A CT scan showing a mass in right lower chest near the heart (left side of photograph).
Lung nodule, right lower lung - CT scan
illustration
-
Lung with squamous cell cancer - CT scan - illustration
This CT scan shows a cross section of the lungs of a person with lung cancer. The two dark areas in the middle of the screen are the lungs. The light areas in the right lung represent the cancer (left side of picture).
Lung with squamous cell cancer - CT scan
illustration
-
Vertebra, thoracic (mid back) - illustration
These are twelve vertebra of the mid back. The last vertebra (on the left side of the picture) attaches to the lumbar (lower) spine, and the top vertebra (on the right) attaches to the cervical (neck) section of the back. The vertebra are broader and stronger than the cervical bones. This allows them to absorb the added pressure applied to the mid back, but they remain a common sight of injury. The vertebra are numbered from one to twelve and labeled T1, T2, T3, et cetera, from the upper most bones to the lowest.
Vertebra, thoracic (mid back)
illustration
-
Normal lung anatomy - illustration
The lungs are a major part of respiratory system. The function of the respiratory system is to supply the body with oxygen and get rid of carbon dioxide.
Normal lung anatomy
illustration
-
Thoracic organs - illustration
The thorax is also called the chest and contains the main organs of respiration and circulation. The heart through its main artery, the aorta, pumps oxygenated blood to all parts of the body. The lungs provide oxygen to the cells of the body and eliminate carbon dioxide. Together these organs sustain some of the most critical life functions of the body.
Thoracic organs
illustration
-
CT scan - illustration
CT stands for computerized tomography. In this procedure, a thin X-ray beam is rotated around the area of the body to be visualized. Using very complicated mathematical processes called algorithms, the computer is able to generate a 3-D image of a section through the body. CT scans are very detailed and provide excellent information for the physician.
CT scan
illustration
-
Thyroid cancer - CT scan - illustration
This CT scan of the upper chest (thorax) shows a malignant thyroid tumor (cancer). The dark area around the trachea (marked by the white U-shaped tip of the respiratory tube) is an area where normal tissue has been eroded and died (necrosis) as a result of tumor growth.
Thyroid cancer - CT scan
illustration
-
Pulmonary nodule, solitary - CT scan - illustration
This CT scan shows a single lesion (pulmonary nodule) in the right lung. This nodule is seen as the light circle in the upper portion of the dark area on the left side of the picture. A normal lung would look completely black in a CT scan.
Pulmonary nodule, solitary - CT scan
illustration
-
Lung mass, right upper lobe - CT scan - illustration
This is a CT scan of the upper lungs. This individual has a mass in upper part of the right lung (left side of picture).
Lung mass, right upper lobe - CT scan
illustration
-
Bronchial cancer - CT scan - illustration
This chest CT scan shows a cross-section of a person with bronchial cancer. The two dark areas are the lungs. The light areas within the lungs represent the cancer.
Bronchial cancer - CT scan
illustration
-
Lung mass, right lung - CT scan - illustration
This is a CT scan of the upper chest showing a mass in the right lung (seen on the left side of the picture).
Lung mass, right lung - CT scan
illustration
-
Lung nodule, right lower lung - CT scan - illustration
A CT scan showing a mass in right lower chest near the heart (left side of photograph).
Lung nodule, right lower lung - CT scan
illustration
-
Lung with squamous cell cancer - CT scan - illustration
This CT scan shows a cross section of the lungs of a person with lung cancer. The two dark areas in the middle of the screen are the lungs. The light areas in the right lung represent the cancer (left side of picture).
Lung with squamous cell cancer - CT scan
illustration
-
Vertebra, thoracic (mid back) - illustration
These are twelve vertebra of the mid back. The last vertebra (on the left side of the picture) attaches to the lumbar (lower) spine, and the top vertebra (on the right) attaches to the cervical (neck) section of the back. The vertebra are broader and stronger than the cervical bones. This allows them to absorb the added pressure applied to the mid back, but they remain a common sight of injury. The vertebra are numbered from one to twelve and labeled T1, T2, T3, et cetera, from the upper most bones to the lowest.
Vertebra, thoracic (mid back)
illustration
-
Normal lung anatomy - illustration
The lungs are a major part of respiratory system. The function of the respiratory system is to supply the body with oxygen and get rid of carbon dioxide.
Normal lung anatomy
illustration
-
Thoracic organs - illustration
The thorax is also called the chest and contains the main organs of respiration and circulation. The heart through its main artery, the aorta, pumps oxygenated blood to all parts of the body. The lungs provide oxygen to the cells of the body and eliminate carbon dioxide. Together these organs sustain some of the most critical life functions of the body.
Thoracic organs
illustration
Review Date: 8/23/2016
Reviewed By: Denis Hadjiliadis, MD, MHS, Paul F. Harron, Jr. Associate Professor of Medicine, Pulmonary, Allergy, and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
