The settings on Cedars-Sinai Medical Center's three CT scanners were changed, causing "immediate jeopardy" in a case that the hospital says involved more than 200 patients who underwent stroke imaging between February 2008 and September 2009, according to a report released last week by investigating California health officials.
The report said that "on or about February 2008, the scanning parameters of three CT Scanners were changed from the manufacturer's recommended output of 80 kv (the amount of voltage delivered) and 200 mA, (milliampere, the duration of the exposure) to 120 kv and 'automatic,' meaning the machine determined mA (usually in the 500 mA range)."
State officials reported that an employee told them "the reason for the change in radiation output of the machines had not been determined, nor had the person(s) who performed or authorized the radiation output changes identified.
Another employee reported that "50 rads (units of radiation exposure-radiation absorbed dose) had been projected to be the dosage to the patients prior to February 2008 for patients undergoing the CT Perfusion Brain Scan procedure. The increased machine settings were calibrated to deliver approximately 7 times the former radiation level."
In a statement last week, hospital officials said they have implemented new policies and procedures. The hospital's plan of correction to prevent future overexposures has been approved by the state.
However, who is to blame for the mishap remains unclear. Hospital officials previously said they did not want to shift responsibility for the incident to the CT scanner's manufacturer, General Electric.
But in its statement last week, Cedars-Sinai officials said the incident "has raised considerable questions about why the manufacturer-set 'auto' mA setting for the brain perfusion CT scan delivered a higher than expected level of X-ray radiation, since 'auto' mA settings in CT and other imaging scanners are generally designed to provide the lowest appropriate level of X-ray radiation."
Cedars-Sinai added the hospital was not the first in Los Angeles that experienced the problem, referring to Glendale Adventist Medical Center.
"On Nov. 20, a second hospital in Los Angeles County reported a similar problem with GE brain perfusion CT scan equipment where patients received higher than expected levels of X-ray radiation," according to Cedars-Sinai's statement.
"Over the past weeks, Cedars-Sinai has received calls from other institutions asking about the incident to learn what procedures Cedars-Sinai has put in place," according to the hospital. "As a result, in its cover letter to the California Department of Public Health, Cedars-Sinai also encouraged the agency to share with other healthcare providers the agency's expectations about policies and procedures to track and trend brain perfusion CT exposure data."
In a statement from GE, the company noted: "Due to pending litigation, we cannot comment on that, but again, there were no malfunctions or defects in any of the GE Healthcare equipment involved in the Cedars incident."
Regarding the case in Glendale, however, GE wrote, "GE Healthcare is concerned for the health of patients who may have received excess medical radiation at Glendale Adventist Medical Center. We are helping the hospital with its investigation, and have sent GE's top CT experts to the Glendale facility where the equipment is located. Knowing that patient safety is the primary concern of Glendale Adventist Medical Center, GE Healthcare will continue to provide its full support to ensure all steps are taken to prevent similar incidents.
"Although this investigation remains ongoing, GE has not learned of any equipment malfunction or problems with GE protocols provided with the CT scanner," GE added.