Hi,
I had 2 MRI scans within 10 days of each other as well as the Nucleur Medical one too.
My Gleason was 5+4+3 (7/7 on left).
I was actually quite pleased and saw nothing sinister in it - I recall thinking " well I'm having a thorough MOT ".
Try not to worry too much. I know that's easier said than done but it sounds like he's having good care and attention.
Best wishes,
John