Wednesday, the New England Journal of Medicine revealed that even though Medicare, the United States government’s health program for people aged 65 or older and the disabled, was investing large amounts of money in state-of-the-art CT scanners, the latter have yet to be proven effective in detecting heart problems. Researchers stated that where CT scans used to diagnose coronary artery blockages were concerned, there was little scientific evidence that they actually worked, reckoning that the government was simply wasting money. Moreover, according to cardiologist Dr. Rita Redberg of the University of California, San Francisco (UCSF), who co-authored the commentaries in the Journal, the same was true for PET scans used to evaluate dementia in patients with Alzheimer’s disease. The study that was published along with the commentaries showed that CT scans were almost as effective as conventional tests in detecting artery blockages, which entail inserting a catheter directly into the heart of the patient. Nevertheless, researchers at Johns Hopkins University in Baltimore revealed that the 64-row computed tomography (CT) scans were 93% as accurate as cardiac catheterization, adding that they furthermore represented a non-invasive diagnosing procedure. Therefore, they believed that CT scans could be well used as an alternative diagnostic instrument or as a replacement for other unclear tests such as cardiac stress testing, which is aimed at detecting reduced blood flow. Still, Redberg and co-author Dr. Judith Walsh of the UCSF emphasized another issue that the CT scans gave rise to, namely radiation exposure, stating that exposure to radiation entailed by this kind of test was double, triple or quadruple the exposure in conventional angiography, which translates as the amount of radiation that 500 X-rays would produce.