A report in the Annals of Internal Medicine earlier this week indicates that smokers have an increased (one in five) chance of having a false positive diagnosis of lung cancer after having a single CT scan to look for the disease. Smokers who have two scans are even more likely to have a false positive—their chances are one in three. False positives indicicate that there is a tumor present when there is none, which can lead to unnecessary procedures and a whole lot of worrying among patients who think they have cancer. Researchers behind the study say that these false positives are twice as likely with a CT scan as they are with conventional chest x-rays.

In related news, FDA just launched a transparency Web site for CDRH as part of its overall transparency initiative. It contains a section on radiation-emitting products.