I had MRI scans on my arm the other day (three scans to cover the whole arm). I was told at the start it would take 45 mins in total - 15 mins for each scan - but it actually took 1 hour 45 mins.
It was constant. No breaks, other than a quick change of position for the second and third scans.
Why did it take an hour longer than the norm? They said I’d stayed nice and still throughout, else I’d have thought it was that.