The chief executive of Cedars-Sinai Medical Center in Los Angeles said that he regretted the "circumstances" that subjected 206 patients to radiation overdoses and laid out reforms made since the hospital discovered that a CT scanner had been set erroneously for 18 months. In a written statement, Thomas M. Priselac said: "We take very seriously our responsibility for operating medical equipment in the safest possible manner, and deeply regret the circumstances that led to patients undergoing CT brain perfusion studies receiving a higher than appropriate level of radiation."