There is a specialized MRI called Diffusion Tensor Imaging that can show damage from a concussion. qEEG's can reliably (97+%) diagnose a concussion if compared to a reliable TBI/mTBI database.

The MMSE can show symptoms of concussion even though many practitioners mutilate the MMSE expecting the same reliability.

The MMPI can be used to diagnose concussion if the scoring is done using the Cripe Neurological Symptoms index. This is very rare.

The Halsted-Reitan battery of NeuroPsychological Assessment tests can be accurate.

Those that work best are not well appreciated. Attorneys try to discount them in litigation.

The question is, What are you trying to get the diagnosis for? Any of these accurate diagnoses without proper presentation will be discounted.