"Probably in this case it made no clinical difference," said Freedman, "but this shouldn't reassure us that next time there wouldn't be a serious overdosage."
Dr. Brahmajee Nallamothu, cardiologist and researcher at the University of Michigan/VA Patient Safety Enhancement Program, said the news of patients getting excess radiation at Cedars-Sinai prompted hospital staff to recheck their CT brain perfusion scan protocol to make sure their machines were working properly.
The FDA also issued an alert last Thursday, urging hospitals nationwide to review their safety protocols for CT scans.
But financial obstacles could prevent proper quality control at many health care facilities.
"I am concerned by the economic pressures that may lead health care systems to lay off physicists and engineers that do not provide clinical revenue, yet they are our radiation safety experts that work hand in hand with the diagnostic radiologists," said Dr. Kimberly Applegate, vice chair of quality and safety in the department of radiology at Emory University School of Medicine. "Ionizing radiation cannot be detected by our natural senses, so we must ensure appropriate dose tracking and quality control of our equipment."
And diagnostic machines that use radiation, including X-ray and CT machines, have spread to private doctors' offices, outpatient facilities and free-standing medical centers, raising concerns about appropriate testing and calibrating, said Dr. Len Lichtenfeld, deputy chief medical officer of the American Cancer Society.
"The volume of CT scans we're doing in the country is considerable," said Lichtenfeld. But he added that the need to reduce radiation is offset by the clinical information necessary to help a patient.
Some doctors suggested that tracking a patient's cumulative radiation dose in their medical record, similar to how cholesterol or hemoglobin is recorded, may help prevent unnecessary radiation exposure.
"It is the wild west out there," said Dr. Richard Semelka, vice chair of quality and safety in the department of radiology at UNC Hospitals. "No one has solved the issue of keeping track of the global exposure of individuals to medical radiation."
Accreditation programs from the American College of Radiology (ACR) for facilities with CT machines could help prevent future errors such as this through consistent guidelines for protocol oversight and standards.
However, only 4,000 facilities nationwide are accredited, according to Shawn Farley, director of public affairs for the ACR, and Cedars-Sinai is not one of these. Farley pointed out that, while a new Medicare rule will force facilities to become accredited, this law does not go into effect until Jan. 1, 2012.
Cedars-Sinai said in a statement that it has instituted "double checks" when protocols are changed, and that an investigation into the incident is underway.