It is not specifically for CTE, and it is not diagnostic. It is an experimental PET imaging agent that binds to Tau tangles (and others). The CTE was diagnosed after his death.
http://www.cnn.com/2015/04/06/health/cte-blast-variant/index.html
In one of the largest studies of its kind to date, Bailes and his co-authors at UCLA compared the living brains of 14 former athletes thought to have CTE, 24 patients diagnosed with Alzheimer's disease and two ex-soldiers, Tommy Shoemaker and Shane Garcie, to a control group of 28 cognitively normal people.
The researchers injected the participants with a radioactive "tracer" called [f-18]FDDNP before their PET scans. The tracer latches on to a brain protein called tau, which is thought to be responsible for much of the damage in Alzheimer's and other degenerative brain disorders, and lights up areas of the brain that are affected.
"For us to be able to make the diagnosis of the injury or the disease in living people is paramount to being able to help them, treat them and to find some way to keep them out of progressing into a terminal problem," says Bailes.
The scans of the ex-soldiers was a plus: a tiny sample designed to give a glimpse into what might be causing their debilitating symptoms.
And they offer a chance to explore what many experts are beginning to suspect: The blasts and energy jolts common in warfare might be creating a new form of CTE, a "blast-variant" version.
"In the military, it seems it would be vitally important to know who has been exposed to this, and then be able to identify, mark, follow the progression of brain degeneration from blast injury," says Bailes. "And to know who's at risk and maybe who needs to be pulled out of harm's way permanently."
Sure enough, the specific pattern of the tau the researchers found in Garcie and Shoemaker's brains didn't look at all like Alzheimer's. Instead, it looked similar to the tau display found in the 14 players suspected of having CTE and the results taken from brain autopsies of people diagnosed with CTE.
