RT Journal Article SR Electronic T1 In the absence of diagnosed concussion in collegiate contact sport athletes, a relationship is suggested between the effects of head impact exposure, white matter diffusivity measures and cognition JF Evidence Based Medicine JO Evid Based Med FD BMJ Publishing Group Ltd SP 157 OP 157 DO 10.1136/eb-2014-101750 VO 19 IS 4 A1 James L Stone A1 Julian E Bailes YR 2014 UL http://ebm.bmj.com/content/19/4/157.abstract AB