My partners and I are starting to notice an uptick in patients walking in to hospitals and imaging centers to have heart and lung CT screening tests, usually after seeing them advertised by the facilities doing the testing. The results often show up in the patients’ primary care providers’ inboxes without any prior knowledge that their patients had the examination(s). The scans typically have out-of-pocket costs in the $49 to $99 range and are not covered by insurance. They are promoted to identify early heart disease and/or lung cancer. 
Unfortunately, many of these scans are done inappropriately, and without a prior discussion of their utility and limitations. There are definite indications for the tests, but it’s also important to know the risks including false positives (seeing things on the scans that have no medical significance, yet cause a great deal of angst for patients), false negatives (not seeing something that is actually there), as well as exposure to radiation.
The coronary artery calcium (CAC) scoring test involves doing a CT scan to see if calcium deposits are present in the walls of the coronary arteries that supply oxygen and other nutrients to the heart. It has been shown that certain amounts of calcium can indicate a person may have coronary artery disease, with an increased risk of suffering a heart attack. 
It’s very important to understand that this test is but one piece of evidence to determine a person’s overall risk of possibly having a heart attack. Patients should contact their primary medical provider before scheduling one of these tests to calculate their risk of heart disease. Risk is based on medical & family history, age, sex, blood pressure, cholesterol values, presence of diabetes and smoking history. Once their risk is assessed, the possible need for a CAC test can be discussed.
People who have less than a 10 percent risk of having a heart attack over the next 10 years (low risk), or are less than 40 years old don’t need the test. The test probably has the most utility in those with an intermediate risk of heart disease (10 to 20 percent chance over the next 10 years). A higher CAC can sometimes make us lean toward being more aggressive with lifestyle changes and medications to prevent a first heart attack. Those with a high risk of greater than 20 percent typically are treated aggressively, no matter what their CAC score.
CT lung cancer screening is another test that should only be performed on specific patients to prevent premature death from lung cancer. The U.S. Preventative Services Task Force recommends yearly screening in patients who: (1) are between 55 and 80 years of age, (2) have a 30 pack-year smoking history (smoked a pack a day for 30 years, 2 packs a day for 15 years, etc.), and (3) currently smoke or have quit smoking in the last 15 years. There is a very low probability of developing lung cancer and dying from it in patients who do not meet these criteria.
I’ve had many patients sign up for a lung scan at the time of their coronary calcium scan. They seem to think as long as they’re getting one scan, why not both – who wants to die of lung cancer? Once again, there are risks to having an inappropriate scan, including radiation exposure, as well as seeing things on the scan that likely have no medical significance. This can lead to worry and additional testing. Before getting either one of these scans, please talk to a medical professional.
-Dr. John Roberts is a licensed medical physician. He writes a weekly column exclusively for Sagamore News Media publications.