More than 200 patients at Cedars-Sinai Medical Center in Los Angeles were inappropriately exposed to high doses of radiation from CT brain scans used to diagnose strokes. About 40% of the patients lost patches of hair as a result of the overdoses, a hospital spokesman said. The overdoses went undetected for 18 months as patients received eight times the dose normally delivered in the procedure, raising questions about why it took Cedars-Sinai so long to notice that something was wrong. As a result of the discovery, the FDA issued an alert urging hospitals nationwide to review their safety protocols for CT scans.