A special computed tomography (CT) scanner called a spiral (helical) CT can quickly provide a scan of the lungs in half the time of a standard CT scan. Spiral CT gets its name from the circular movement of the scanner around your body. Spiral CT scan is being studied as a screening test for lung cancer.

The advantages of a spiral CT scan over standard CT scanning include:

• A shorter test time. Movement can affect the scan, so it may be easier to hold your breath during a shorter scan time.
• Better pictures of the lungs and other organs.

Spiral CT to detect lung cancer is not a routine test because of:

• Cost.
• Access. This test is not available everywhere.
• The chance of false-positive results, which could lead to unneeded tests or surgery. This is a concern if small noncancerous nodules are found on the spiral CT.
• The lack of clear evidence that having a spiral CT improves a person's long-term outcome (prognosis).

A spiral CT scan is more likely to be considered for people who have a high risk for lung cancer.