As far as I am aware, the only real insight an MRI will provide as it relates to Alzheimer's are fairly late term changes - like loss of cortical volume.

Cognitive testing by Neuropsychiatrists are how I prefer to trend progression over 12-18 month chunks of time.

Slowing that progression is the holy grail. I dont believe there are any meds that make a material difference. But I do believe that specific usage “exercise” can slow things down. Its about laying down new neuronal pathways. Function on a well used pathway may decline, but I try to develop new ones via new knowledge chains - in the hopes it will provide the equivalent of an alternate route for whatever I am asking my brain to do at that moment.

All that said to suggest that small concise bits of learning anything new should be helpful even if they dont seem useful. Can’t hurt is my view.