Most of us can't stay still for 45 seconds, much less 45 minutes. But that's just what you're asked to do many times when you get an MRI or magnetic resonance imaging test. To make it worse, you must do that while lying in a small tunnel.

Those who administer them at Rush Hospital admit it can be very hard for some, though they do the best they can to relax them, including playing soothing music.

"Claustrophobia is a big issue, but the music does relax you and the techs try to relax you before you get in the machine," said Carla Phillips.

But as difficult as MRIs can be, they're too important to avoid, because they can see things other tests just can't, especially when doctors are trying to diagnose neurological and orthopedic issues.

Phillips said they're invaluable, especially when trying to diagnose back and spinal issues.

"It's the only thing that will show pinched nerves, bulging discs and herniated discs, if the other disc is pushing on another nerve that could be causing pain in your legs," Phillips said.

MRIs are also good for diagnosing ligament and muscle tears. Unlike some other procedures, they're non-invasive, meaning there are no cuts are needles.

Experts say the pluses of the MRI far outweigh the minuses of the cramped space.

If you believe you might have claustrophobia issues during an MRI, you can ask your doctor for a medicine to calm your nerves, like Valium.