Millions of Americans, especially children, are needlessly getting dangerous radiation from "super X-rays" that raise the risk of cancer and are increasingly used to diagnose medical problems, a new report warns. (File Photo) Photo Gallery>>>

    BEIJING, Nov. 29 -- Millions of Americans, especially children, are needlessly getting dangerous radiation from "super X-rays" that raise the risk of cancer and are increasingly used to diagnose medical problems, a new report warns.

    In a few decades, as many as 2 percent of all cancers in the United States might be due to radiation from CT scans given now, according to the authors of the report.

    The risk from a single CT, or computed tomography, scan to an individual is small. But "we are very concerned about the built-up public health risk over a long period of time," said Eric J. Hall, who wrote the report with fellow Columbia University medical physicist David J. Brenner.

    A previous study by the same scientists in 2001 led the federal Food and Drug Administration to recommend ways to limit scans and risks in children. But CT use continued to soar. About 62 million scans were done in the U.S. last year, up from 3 million in 1980. More than 4 million were in children.

    Since previous studies suggest that a third of all diagnostic tests are unnecessary, that means that 20 million adults and more than 1 million children getting CT scans are needlessly being put at risk, Brenner and Hall write.

    CT scans became popular because they offer a quick, relatively cheap and painless way to get 3D pictures so detailed they give an almost surgical view into the body. Doctors use them to evaluate trauma, belly pain, seizures, chronic headaches, kidney stones and other woes, especially in busy emergency rooms. In kids, they are used to diagnose or rule out appendicitis.

    But they put out a lot of radiation. A CT scan of the chest involves 10 to 15 millisieverts (a measure of dose) versus 0.01 to 0.15 for a regular chest X-ray, 3 for a mammogram and a mere 0.005 for a dental X-ray. The risk accumulates over a lifetime.

    Both doctors and patients need to be more aware of radiation risks and discuss them openly and future generations of devices using less radiation should help alleviate the concern, the doctors said.

    (Source: China Daily/Agencies)