Figure 2 HITS System and Riddell Helmet (IMAGE) Radiological Society of North America Caption This is a HITS system and riddell helmet. Credit Radiological Society of North America Usage Restrictions May use with credit. 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.