I was watching a piece on this matter a day or two ago. They were discussing that CTE testing is not far away from testing on living subjects. It prompted me to read up on the matter. Here is one article I found.
http://www.nydailynews.com/sports/football/researcher-5-years-cte-test-living-article-1.2519688
http://www.nydailynews.com/sports/football/researcher-5-years-cte-test-living-article-1.2519688