New Zealand Celsias

A new study led by researchers at the University of California, San Francisco (UCSF) and Group Health Research Institute   is raising concerns about the overuse of CT scans, MRIs and other types of medical imaging and the amount of radiation patients receive.  The results show that the use of medical imaging equipment is rising even in health maintenance organizations (HMOs) that have

The study, published in the June 13 edition of theJournal of the American Medicine Association(JAMA)   is the first of its kind to examine how radiation exposure has grown within large integrated health-care systems.  It showed a dramatic increase in imaging rates and that more patients are being exposed to very high levels of radiation, a potential cause of certain cancers.  According to the research, the number of patients who were exposed to high radiation doubled from 1996 to 2010.  The number of ultrasounds doubled, the number of CT scans tripled, and the number of MRIs quadrupled.  The study also showed that the amount of radiation varied from system to system, with some types of imaging being done five-to-ten times more often with one type of equipment compared to others.

Imaging techniques such as such as CT and PET scans use ionizing radiation that has been linked to cancer, while ultrasounds and MRIs do not.  The study found that not only has the average amount of radiation increased over the last 20 years, but also older adults received the most CT scans.  For each 100 patient aged 65-75, nearly 35 CTs were obtained.  And in a recent study published in the Lancet  , results showed that children exposed to only two or three CT scans have a higher chance of developing brain cancer and leukemia later in life.

Scientists at Duke University found that radiation in CT abdomen scans could be cut by 50 percent and still let doctors accurately diagnose appendicitis.  The researchers also found that radiation could be reduced substantially and still allow for the detection of nodules on the lung and kidney stones.  Scanning equipment makers have been working on quality-control measures designed to prevent patients from being exposed to excessive radiation while still providing doctors with the necessary images.

Quoted in an article in the Wall Street Journal  , Paul Ellenbogen, chairman of theAmerican College of Radiology  ’s Board of Chancellors, said, “Now we know it’s better to get a lower dose and a less-pretty picture but still have the information needed to get the diagnosis.”

The Choosing Wisely Initiative  , a consortium of medical groups including the American College of Radiology, released five recommendations in April for physicians and patients with regard to the use of imaging machines.  They include not using imaging for an uncomplicated headache, avoiding chest x-rays for ambulatory patients with “unremarkable” medical histories and exams, and not performing CT scans on children until ultrasound has been considered as another option.

The UCSF study’s lead author, Rebecca Smith-Bindman, MD, a professor of radiology and biomedical imaging at UCSF, said that patients themselves as well as doctors can address the problem of overexposure to radiation:

• Ask doctor whether scans are necessary or whether they can be deferred.
• Understand fully the necessity and safety of any radiological scan.
• Be certain the medical facility that provides the scan closely monitors radiation exposure to protect patients against the overuse of scans, repeated scans, or doses that are higher than necessary.