What is low-dose CT and how can it be used to screen for lung cancer?

Low-dose computed tomography (LDCT) is a special type of CT scan that provides a lower radiation dose than regular CT and a more detailed image of the chest cavity than X-rays.

What should I expect before the test?

Tell your doctor if you have a heart condition such as heart failure.
Remove all accessories (women may need to remove their bras) and change into your exam gown.
See your doctor for more information about the need for your test, the risks, the procedure, or the significance of the screening results.

How is the test done? What should I look for when I get tested?

A CT scan is usually done by a radiologist.
During the exam, you will lie on an exam bed attached to a CT scanner. The exam bed goes into the circular opening of the scanner and then moves around the subject’s body while the scanner takes pictures. You may hear a clicking or buzzing sound as the bed and scanner move. Moving the body can make the examination impossible or affect the accuracy of the results, so be careful.
During the exam, you may be alone in the CT scan room. The radiologist will be watching from the window. You can talk to the doctor through a two-way intercom. The entire exam takes about 30 minutes. For most of the time, you are preparing for the scan, and the actual scan takes only a few seconds.
There is no need to be nervous, and the test does not cause pain. However, the exam bed may feel hard and the scan room may be cold.

What do the test results mean?

Your doctor may give you complete results within 1 to 2 days.
Possible results are listed in the table below.

abnormal

One or more nodules are found, and if at least one of them is large enough, your doctor may recommend further testing.
Next step: Your doctor may recommend any of these tests.

More scans, such as a CT scan or PET scan.
Bronchoscopy, where the doctor looks inside the airways.
Biopsy, which is the only way to diagnose cancer. The doctor removes a small sample of lung tissue, and a pathologist looks at the sample under a microscope to look for suspicious lesions.

Results	Specifics
Normal	No growths (nodules) were found in the lungs. Next step: another LDCT in one year.
One or more nodules are found, but are small enough that no action is needed at this time. Next step: another LDCT in 3 to 6 months.