U.S. health regulators have uncovered another 50 patients who received radiation overdoses from CT perfusion scans. The U.S. Food & Drug Administration (FDA) has been investigating botched CT scans since October, after patients at Cedars-Sinai Medical Center in Los Angeles complained of symptoms of radiation overdose.

According to the agency,  all of the patients  investigated so far were exposed  to excess radiation of up to eight times the expected level during their CT perfusion scans.  These cases, to date, involve more than one manufacturer of CT scanners. Some of these patients reported hair loss or skin redness following their scans. High doses of radiation can cause cataracts and increase the risk of some forms of cancer.

According to the AP, the FDA is investigating the use of CT scans at Glendale Adventist Medical Center and Providence St. Joseph Medical Center in Burbank, California.

In October we wrote that reported complaints numbered at 206, reports are now up to 260, according to the AP. Some reports have also been received from an unnamed Huntsville, Alabama hospital, said the AP.

Alicia Gonzalez, a spokeswoman for Glendale Adventist said the specialty scan that appears to be linked to the problem is no longer in use, said the AP. ”This procedure has been discontinued,” she said in a statement, quoted the AP. St. Joseph Medical Center had no comment, said the AP.

The FDA has not yet determined if the over exposures are a result of human error or some sort of equipment problem, reported the AP.

Although Cedars-Sinai and Glendale Adventist both use General Electric scanners, the FDA said reports have been received from other hospitals using different scanner brands, including more than one Toshiba model, explained the AP. Arevind Gopalratnam, a spokesman for GE issued a statement that said, in part, ‘there were no malfunctions or defects in any of the GE Healthcare equipment involved.”