What does an mri procedure entail for the patient

MRI scanners do you strong magnetic field, radio waves, Enfield gradients to generate images of the organs in the body.

Well if you pick a machine to work on and that's gonna be your exercise if you don't stick to that machine your muscle strength your muscle mass rather will change because you haven't been doing it you change something in your exercise routine which changes your body's form of dealing with things for example you might become weaker or stronger depending on what kind of exercises you do in whether or not the machine you picked actually your muscles grow.

They probably don't understand either 1. what the nightmare is about or 2. his anxiety and stress