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Thoracic CT How the Test is Performed:
You are asked to lie flat on a narrow table that is then guided into the CT scanner. The scanner emits X-rays from a complete circle around you. Each "slice" of X-rays lasts a few seconds, then the table is advanced into the scanner a slight amount, and a new "slice" of X-rays is taken. The complete scan often lasts between 1/2 and 1 hour.
A contrast-medium (dye) may be inserted into a vein to help define blood vessels and certain tissues. During the test, it is very important to remain still. If you are restless or traumatized, you may be given a sedative. The technologist operating the computer may indicate when it is necessary to control breathing. A sound system is built into the machine to allow for communication during the test.
How to Prepare:
Fasting for 4 to 6 hours may be recommended if contrast dye is to be used or if sedation is anticipated. You will wear a hospital gown during the procedure. You must sign a consent form before the procedure.
Infants and children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experience, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:
How it Feels:
If a dye is needed to increase the contrast between different tissues or organs, it is administered by injection into a vein. The injection may sting, and the injection site may be tender to the touch for several minutes. After the injection, there may be a warm or flushed feeling for a few seconds.
The X-rays are painless, and the test is only mildly uncomfortable. Some people experience claustrophobia or anxiety when placed within the scanner. If you usually becomes anxious when in an enclosed area, inform the technician before the test.
Risks:
CT scans and other X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to reproduce the image. During pregnancy , a thoracic CT scan is not recommended unless the benefits outweigh the risk of radiation exposure to the fetus. CT scans provide low levels of radiation.
The most common dye used is iodine-based. A person who is allergic to iodine may experience nausea , sneezing , vomiting , itching , or hives . In people who are sensitive to iodine, the dye may occasionally cause anaphylaxis (life-threatening allergic response ) or toxic effects to the kidneys.
Why this Test is Performed:
Thoracic CT may be recommended when there is a need for examination of the structures inside the chest. It is noninvasive and poses less risk than invasive procedures (such as angiography or exploratory surgery).
Common indications for thoracic CT include: - when there is a chest injury
- when tumor or mass (aggregation 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
Normal Values:
No abnormalities of organ size and position. No abnormal growths or fluid collections.
Abnormal Results:
Thoracic CT may show many disorders of the heart, lungs, or chest area, including: Additional conditions under which the test may be performed:
Cost:
The cost varies greatly The costs include the use of the equipment (approximately $180), cost of supplies, radiologists fees, etc. The total cost is approximately $400 to $600. Special "non-iodine" contrast dye may increase the cost slightly.
Special Considerations:
The benefits of a CT scan usually far outweigh the risks of the X-rays. A CT scan is one of the best ways of "looking" at soft tissues such as the heart and lungs.
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.
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.
This CT scan shows a single lesion (pulmonary nodule) in the left 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.
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).
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.
This is a CT scan of the upper chest showing a mass in the right lung (seen on the left side of the picture).
A CT scan showing a mass in right lower chest near the heart (left side of photograph).
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 left lung represent the cancer.
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 etc. from the upper most bones to the lowest.
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