A meta-analysis of 16 studies published in the Annals of Internal Medicine finds that low-radiation heart CT scans, known as gated CT’s, are equally effective in diagnosing heart problems as a coronary angiography, the current gold standard. The angiogram, done via a catheter inserted through an artery into the heart, however, is invasive and not without risk, so some doctors resort to a CT scan for diagnosing patients with chest pain instead. Researchers note that a standard CT heart scan exposes patients to 12 millisieverts of radiation, which they claim may increase their risk for cancer. But low-radiation CT scans cut the radiation dose to less than 3 millisieverts, which is about equal to the normal background radiation we are all exposed to. According to the study results, they can rule out heart problems as effectively as the catheter-based method.
“While I find it hard to believe that even the radiation dose from a regular CT scan equivalent to four-times the background exposure is enough to cause cancer, I guess if the same diagnostic yield can be attained with lower exposure, why not?” says ACSH's Dr. Gilbert Ross. What is important to remember is that low-radiation CT scans are only meant to diagnose heart problems in patients with symptoms and should not be used as a screening test, which Dr. Ross fears might happen as some organizations, seeking to exploit people’s fears of having asymptomatic heart disease, will peddle as part of a routine physical exam.
