Have you ever had an MRI, CAT scan or other radiological test? The use of such tests has surged by 50% in the last 5 years. They're potentially life-saving tests. But they're also over-prescribed by doctors who are afraid of being hit with a malpractice suit for not running the tests. This is also known as "defensive medicine."

To complicate matters, the big insurers are now using RBMs -- radiology benefits managers -- to assess whether they want to cover the procedures or not. A Wall Street Journal reporter found case after case where an insurer would pre-certify a radiological test and then, after the fact, turn around and deny payment based on the recommendation of their RBMs.

So what can you do? Before you proceed with any radiological test, get approval in writing -- even if pre-authorization isn't necessary. Don't settle for approval over the phone; you must get it in writing.

If you've already had a test done, and you're getting a referral to another doctor who is suggesting another test, take your films with you instead of undergoing a duplicate test.