Dr. Pratik Mukherjee, a radiologist specializing in brain imaging, sits in front of an MRI scanner at the UCSF China Basin campus in San Francisco.
With time and rehab, knee injuries mostly heal. But concussions can be another thing, especially for young athletes. This summer California lawmakers are expected to pass legislation requiring coaches to take concussion awareness and response training. But signs of a head concussion can be hard to spot, especially when players don't know or won't admit they've been injured because they want to stay in the game. Reporter: Deirdre Kennedy