George love you are NOT a coward, and as the radiographer says it does happen often. Its a very unatural situation to be forced and held in, rather like a metal and plastic huge coffin.
I am very suprised he didnt tell you that the bridge would drop down to hold you still, he should have gone through everything with you before the procedure.
A lot of patients are given calmers before such as this but in your case it may not have been suitable because some meds supress breathing.
There are other options but the MRI is more detailed.
The best thing you can do now is forgive yourself for your reaction and forget it. Dont you know life is too short to worry?
