I'm with Joanne, have a neuro-psych.

A conventional MRI will not be able to image your injury. At best, it might show blood deposits from shearing for up to three years post concussion. There are speciailzed MRIs that "might" show the structural damage, but they're very expensive and won't tell you how the damage is actually playing out in your behavior, cognition, motor skills, etc...

Those blank bits of your day sound very much like absence seizures. Have you discussed that possibility with your doctor. Are you on any anti-seizure meds?

If you want the big song and dance on speciality MRIs and/or neuropsych testing, let me know.

Cheers