The U.S. Food and Drug Administration has been investigating reports that patients undergoing computed tomography (CT) brain perfusion scans were accidently exposed to excess radiation. The FDA found that when properly used, the CT scanners did not malfunction.

Instead, it is likely that the improper use of the scanners resulted in these overdoses. However, the FDA has identified a series or promising steps to enhance the safety of these procedures. These steps could reduce the likelihood of radiation overexposure in the event of improper use of the CT scanners.

FDA has sent a letter to the Medical Imaging and Technology Alliance reporting on the results of the investigation and discussing possible CT equipment enhancements that could improve patient safety.  The agency will hold follow up discussions with manufacturers on the changes.

Those changes include: 

• A console notification to alert the operator of a high radiation dose
• Providing particular information and training on brain-perfusion protocols to all facilities that receiving base CT equipment, whether or not the facilities purchase the related software enabling quantitative analysis of cerebral hemodynamics;
• Clarification of parameters affecting dose, along with clear instructions on how to appropriately set those parameters; and
• Organization of all dose-related information into one section of each user manual, in a dedicated dose manual, or indexed comprehensively in a concordance covering all manuals.