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Ency. home > Test > T > Thoracic CT

Thoracic CT    See images

Overview | Risks | Results

Alternative names:

Chest CT; CT scan - lungs; CT scan - chest

Definition:

A CT scan (computed tomography) of the chest and upper abdomen.

How the Test is Performed

The patient will be asked to lie on a narrow table (gantry) that slides into the center of the scanner. Depending on the study being performed, the patient may need to lie on his/her stomach, back, or side. If contrast media (dye) is to be administered, intravenous access will be placed in a small vein of a hand or arm.

Much like standard photographic cameras, subject motion causes blurred images in CT. Therefore, the technologist operating the scanner and supervising the patient will give instructions through an intercom when to hold one's 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, however, additional contrast-enhanced or higher-resolution scans will add to the scan time. The newest multi-detector scanners can image the entire body, head to toe, in under 30 seconds.

How to Prepare for the Test

The health care provider may advise fasting of solids and liquids for 4 to 6 hours if contrast dye is to be used.

The CT scanner has a weight limit to prevent damage to the mechanized gantry. Have the health care provider contact the scanner operator for weights greater than 300 pounds.

Since metal is very, very dense, the X-ray beam has difficulty passing through it and results in errors in the involved constructed slices (artifact). Therefore, the patient may be asked to remove jewelry and wear a hospital gown during the study.

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 experiences, 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 the Test will Feel

The X-rays are painless. The primary discomfort may be from the need to lie still on the table.

If intravenous contrast dye is given, the patient may initially feel a slight burning sensation within the injected arm, a metallic taste in the mouth, and a warm flushing of the body. These sensations are normal and usually reside within a few seconds.

Why the 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

Ency. home > Test > T > Thoracic CT

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