Edward Ahn, M.D., Johns Hopkins Medicine (IMAGE) Johns Hopkins Medicine Caption Pediatric neurosurgeon Edward Ahn, M.D., and colleagues at the Johns Hopkins Children's Center have designed a CT scanning method that cuts radiation exposure in children who need repeat brain scans. Credit Johns Hopkins Medicine Usage Restrictions one-time use only License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.