Within the last few years, some patients across the country who underwent sophisticated brain scans to determine if they had suffered strokes began to experience odd symptoms, including a stripe of baldness running around the backs of their heads, memory loss and confusion.
Eventually, doctors discovered that the problem stemmed from accidental radiation overdoses from the analytical procedure itself, known as a CT brain perfusion scan.
An investigation by The New York Times, however, has found that the radiation overdoses were larger and more common than previously known–involving about 400 patients at eight hospitals, including six in California. And experts believe that patients may face long-term risks of cancer and brain damage.
A number of the overdoses were caused by technician error, but public records and the Times’ interviews with hospital officials raise concerns about the role manufacturers play–from how they design the scanning equipment and software to the way they train the technicians who use them.
Some of the hospitals claim they had used settings on the machines that were supposed to reduce the dose of radiation used in the tests, but instead increased it, the Times reported.
Even when done properly, CT brain perfusion scans deliver a large dose of radiation — the equivalent of about 200 X-rays of the skull. But there are no hard standards for how much radiation is too much. The overdoses highlight how little some in the medical profession understand about the operation of these scanning devices and the nature of radiation injuries, as well as the loose requirements for reporting accidents when they are detected.
An official of the U.S. Food and Drug Administration, which began its own investigation late last summer and has yet to issue a report, said the agency is now considering expanding its probe, based on the new revelations.
Related Links: Health Experts Sound Off on Ways to Reduce Radiation From Scans
The New York Times article accurately states that government officials say none of the overdoses described in the story “can be attributed to malfunctions of the CT scanners.” In fact, medical imaging is heavily regulated by a wide range of federal, state, and international requirements, including the Food and Drug Administration (FDA), International Electrotechnical Commission (IEC) standards, state regulatory health agencies, among others, all of which work to control radiation exposure and minimize dose. Manufacturers of CT equipment also take the issue of radiation dose extremely seriously and have worked tirelessly to develop new technologies to reduce the amount of dose necessary for a clear image.
In addition to existing safeguards already in place, earlier this year manufacturers released a Radiation Dose Reduction Plan, which includes support for mandatory reporting of medical errors associated with ionizing radiation, certification of imaging technologists and accreditation of imaging facilities.
Further, CT manufacturers also have spearheaded the CT Dose Check Initiative, which is a commitment to include a new Dose Notification feature to reduce the dose levels associated with scans; a Dose Alert to prevent medical errors; and a new dose recording feature to help track dose and to develop reference dose levels to help providers understand how their facility compares to local and national standards. Manufacturers are working closely with FDA to ensure these features will begin to be included on new CT machines this year. Importantly, we have also committed to including these features on appropriately compatible scanners in the installed base as well.
Advances in imaging technology have revolutionized medicine, turning patients into survivors. Like all technologies, there are risks associated with its use. Manufacturers take these risks seriously and will continue to do our part to ensure that every imaging procedure is both medically appropriate for the patient’s condition and safe.
David Fisher
Executive Director
Medical Imaging and Technology Alliance (MITA)
After a severe collision when another driver rear-ended my auto with such force the car collapsed and some piece of debris split open the skin on the back of my head, and case brain injury, I was given a CT scan at the hospital in South Laguna, CA. (now Mission Hospital, Laguna Beach. Is my hospital on the list? I completed two years of cognitive rehab 7 years after the incident, and have finally been able to function. Was my condition exascerbated by excessive radiation?