Progress on diagnosing CTE in living patients does appear to be making progress. Eg here is one avenue based on a potential biomarker.
https://www.sciencedaily.com/releases/2017/09/170926143601.htm
Here is another that uses PET scans in concert with a detectable marker that attaches to proteins known to exist in the brains of people who suffered from CTE
https://www.sciencedaily.com/releases/2014/09/140916102222.htm
It’s the same technique that lead to this more recent story
http://www.cnn.com/2017/11/16/health/cte-confirmed-in-first-living-person-bn/index.html
Not a formal CTE diagnosis but measure (and in some cases extreme) differences in the brains of living football players
https://www.thespec.com/news-story/7533244-collision-course-concussions-are-ticking-time-bomb-for-former-players/
potential biomarkers are just that. potential. I know something about biomarker development, its not as easy as getting something that looks promising and then rolling int out and then hoping that it has predictive value. We don't need another definitive assay, IHC works fine. pathologists can roll it out at will, provided they have the tissue, We need something that we can give to patients so that we can rationally inform them of the consequences of their decisions OR to inform on treatment ( which we also, don't yet have).
There are tons of potential biomarkers, GFAP in blood for concussions was recently proposed. if that EVER gets to the clinic its not going to be next week, next month or next year.
as for the first one, I find that curious. PET scans imply that the tissue is metabolically active. This is generally not the case in patients who have been diagnosed with CTE because, as I have said, they all share one universal characteristic, they are dead. so how those two go together is not clear to me.
that being said, I am all for more experimetal approaches to try and detect CTE and a variety of other diseases. I think that these approaches, even if the majority of them fail, are worth it based on the benefit of the unlikely chance that one does not. But we are not there yet. we are not CLOSE to being there yet. and even if we get there, the idea that these approaches are predictive is still VERY MUCH unknown, as has been shown by the PSA debacle.
if you think that we are on the precipice of having a diagnostic tool to detect CTE, conside this. We currently have only recently accepted molecular tools to diagnose Alzheimer's ( one immunological, beta amyloid in the CSF and one imaging based). But alzherimer's is characterized by specific behavioural symptoms. CTE is not. We have no idea how CTE affects behaviour/cognition or memory.
its easy to get misled by the daily PR from sites like science daily that we are going to cure disease X or that chocolate staves of cancer or that chocolate causes cancer. I get there is a reason to be optimistic. but we have to be cautiously if not skeptically optimistic. our track history of transitioning things that are " promising" into things that directly help patients is ABYSMAL. whether one is an optimist or a pessimist doesnt change the fact that RIGHT NOW, not accounting for all possible possibilities and permutations in the future, there is ONE and ONLY ONE accepted way to diagnose CTE, and that this diagnosis requires that the "patient" be dead.