Computed tomography (CT) lung cancer screening is a scan of the chest that is used to detect lung cancer. It is recommended for longtime smokers with no signs of lung cancer. Lung cancer is one of the most common types of cancer in adults, especially those with a history of smoking. Early detection of lung cancer may help improve outcomes and increase your chances of survival. CT lung cancer screening can detect signs of disease before you have any symptoms.
CT lung cancer screening uses a special technique called low-dose computed tomography (LDCT). While similar to conventional CT scanning, LDCT uses up to 90 percent less radiation than a conventional CT chest scan. Research from the National Cancer Institute National Lung Cancer Screening Trial has shown that low-dose CT screening can reduce deaths from lung cancer by 20 percent compared to X-ray.
Please refer to the About CT section for more details about CT scanning and the associated risks and benefits.
The leading cause of death from cancers is due to lung cancer and the leading cause of lung cancer is smoking. If you are or have been a heavy smoker, your healthcare provider may recommend a CT lung cancer screening. If lung cancer is detected early, long-term outcomes may be improved. CT lung screening may be recommended if you:
- Are age 50-77
- Are asymptomatic (no signs or symptoms of lung cancer)
- Have a tobacco smoking history of at least 20 pack-years (one pack year=smoking one pack per day for one year)
- Are a current smoker or one who has quit smoking within the last 15 years
Many professional medical associations recommend lung cancer screening for people at high risk of developing the disease. Ask your doctor if you should be screened.
- CT scans can detect even very small lung nodules making the test ideal for screening for lung cancer. When lung cancer is detected early, it is more treatable, and patients have a better chance for survival.
- Low-dose CT scans use up to 90 percent less radiation than conventional lung CT scans.
- CT lung cancer screening is fast, noninvasive, and painless.
- Unlike MRI, if you have metal in your body (shrapnel, bullets, needles, etc.) or an implanted medical device, you can still have a CT scan since no magnets are used in the procedure.
- X-rays used in CT scans have no immediate side effects and do not remain in the body.
- Even though CT scans are very accurate, sometimes a “false positive” test can occur. This means the CT scan results are abnormal, but no lung cancer is present.
- Depending on the results of the CT lung cancer screening, further testing may be recommended, such as lung biopsy. These tests, and any treatment afterwards, may not improve your overall health. Further tests and treatment may also lead to complications and additional cost.
- CT lung cancer screening may fail to detect a cancer. This is called a “false negative” test, and this may cause delays in diagnosis and treatment.
- Health insurance companies and Medicare may only cover LDCT scan costs for lung cancer screening in patients who meet certain criteria (see When is CT lung cancer screening recommended?).
- CT lung cancer screening is available at multiple ARA imaging centers and takes a total of about 10 to 15 minutes.
- You will be asked to change into a hospital gown for the procedure.
- Since metal can distort the CT images, all metal objects and jewelry should be removed prior to the exam. This may include hearing aids, removable dental prostheses, eyeglasses, piercings, hairpins, etc.
- The CT scanner is a large box shaped machine with a large hole in the middle.
- You’ll be placed on a moveable exam table which may have straps or bolsters to help keep your body from moving. You will need to remain as still as possible so the images will be clear.
- The technologist will leave the CT scan room where you are and conduct the exam from a computer in a nearby room. You will be able to talk with the technologist at all times.
- The table will make a first quick pass through the scanner to set your body position. Next, the table will move your body through the scanner more slowly while the CT images are being taken. It may require several passes through the machine to complete the scan.
- You may hear slight buzzing, clicking or rotating sounds during the scanning process.
- You may be asked to hold your breath for 5-10 seconds during the scan. Breathing or any other movement can distort the images.
- When the scan is finished, you may be asked to wait a few minutes while the technologist checks the quality of the images. If needed, more images may need to be taken.
- Wear comfortable, loose fitting clothing. You may want to leave all jewelry, piercings and any other metal objects at home.
- Follow your regular diet and take all your medications as usual.
- Inform your radiologist if you are pregnant. Although the risk of LDCT is very low for the unborn baby, your doctor may choose an alternate exam. Depending on the circumstances, both the physician and patient may decide it is necessary to go ahead with the CT scan. Also, pregnant women should not receive IV contrast unless the benefits clearly outweigh the risks. For more details, please refer to the section
- What if I am pregnant? Can I still have a CT scan?
- Inform your health care provider if you have had a recent lung infection. You may need to wait a certain period of time after the infection clears up to have a CT lung screening.
- CT lung screening is fast and painless. If you feel like you might be anxious during the exam, tell your scheduler. ARA technologists and our clinical staff are experts at helping people through CT exams with minimum anxiety.
- You can return to your normal activities after the exam.
A radiologist, a physician specifically trained to interpret radiological examinations, will analyze the images and send a signed report to the provider who referred you to ARA. The physician will then share the results with you.