A standard MRI doesn't show concussions. The use of a MRI in concussions is used to rule OUT more sinister pathologies, like a brain bleed or tumor. A MRI is designed to detect structural injuries, like a stroke or severe traumatic brain injury for example. Think of these as a hardware problem. Concussions are a functional injury and thus are not detected by MRI. Think of them as a software problem. Take home point: A standard MRI is not used to diagnose concussion and may not be warranted in some instances. The treating physician will determine if a MRI post concussion is needed.
Write up by Molly Parker
It is imperative that one gets an MRI as soon as possible after the hit. A CT scan is crap and only shows the bare minimum. In the case of Diffuse Axonal Injuries (DAI), the damage presents itself 7-10 days after the injury. This time window is critical since the traces of DAI disappear after this time span.