Once again, the agency that runs Medicare is shining a spotlight on the secretive world of hospital fees. And it shows that the sticker prices for outpatient procedures — like MRIs and ultrasounds — may vary by 200 percent or more, even within the state of Minnesota.

The latest prices for 30 common outpatient procedures were made public last week by the federal Centers for Medicare & Medicaid Services, only weeks after it released the hospital charges for 100 common inpatient procedures, which showed similarly eye-popping variations.

The website (www.startribune.com/a2297) takes a little work, but if you search for Minnesota, you’ll find:

• The charge for an ultrasound is $481.22 at Cambridge Medical Center, and $151.09 at Douglas County Hospital in Alexandria.

• An MRI is $3,151.58 at Mayo Clinic’s St. Marys Hospital in Rochester, and $939.96 at Park Nicollet’s Methodist Hospital in St. Louis Park.

• Cardiac imaging is $5,772.17 at Woodwinds Hospital in Woodbury, and $1,843.17 at Sanford Bemidji Medical Center.

In fairness, only a tiny fraction of consumers actually pay those charges, and Medicare sets its own reimbursement rates, which don’t bear any resemblance to the sticker prices.

Hospitals are required to set a price list, known as a charge-master, but it doesn’t really tell consumers what they’re paying, said Joe Schindler, vice president of finance for the Minnesota Hospital Association. The only ones who actually pay the sticker price are workers’ comp and auto insurance claims — a tiny portion of patients. Everyone else, including the uninsured, gets a discount, he said, and that can vary widely.

Most consumers only find out the true cost from their insurers after the procedure takes place.

But all the attention is forcing hospitals to start rethinking how they price their services, Schindler said.

“I think this will be an ongoing discussion among our membership,” he said. “Hopefully, it will bring more rationality to the charge structure.”