The technician usually has foam earplugs for you. Use them. Twist them up tight then insert them. The yellow foam ear plugs work best.
Open MRI is a sidewards U or such. It is a much larger opening often used for large people. As I said, it is not as good.
I would consider it a risk of being a waste of time. There is a risk of a false negative due to the poor resolution.

There is a new HIGH Field Open MRI that can do a good job. See this link: http://www3.americanradiology.com/pl...rticle_id_in=5

Ask about the difference. Closed MRI is usually 1.5 Tesla. Open can be as low as 0.2 Tesla. Hitachi makes a 1.2 Tesla Open MRI. With either one, they will need to put a image signal receiving cage over your head. It is open enough that you should not have a problem with it.