Use of MRI, CAT scans rising in hospital emergency rooms

But health officials and others worry about the safety and cost of all that scanning.

“I wish I had an answer as to whether that’s great news or bad news,’’ Dr. Rita Redberg, a cardiologist at the University of California, San Francisco, said of the increased use. Redberg, who has written about safety concerns of using CAT scans, called the new statistics “astounding.’’

Without firm guidelines as to when the scans are medically necessary, it’s hard to say whether the increased use is excessive, Redberg and others said.

The CDC’s National Center for Health Statistics reported the numbers in its annual summary of US data on disease conditions, health behaviors, and use of medical services. The scan figures are based on visits to about 500 hospitals and 3,000 doctors’ offices and outpatient clinics.

Researchers counted three kinds of scans: MRIs, or magnetic resonance imaging, which use powerful magnets and radio waves, CAT scans, or computerized axial tomography, which combine X-rays with sophisticated computers, and PET scans, or positron-emission tomography, which use X-rays and a radioactive substance.

The scans are expensive - a single CAT scan can cost $500 to $1,000, and MRIs and PET scans can be much more expensive. The federal Medicare program has been trying to hold down imaging costs since its annual bill reached $12 billion.

Studies have not yet clearly demonstrated that the scans are lowering death rates, said Redberg, who is editor of the Archives of Internal Medicine.

There also is concern about radiation from scanners.