As high-tech scanners proliferated, the Minnesota Department of Health last year began tracking machines not just in hospitals but also in physicians' offices and independent centers. There's particular concern with scanners owned by physicians, because studies show physicians who self-refer tend to order more services at a higher cost than physicians who do not self-refer. Here's a look at the number of MRI and CT scanners:

Minneapolis MRI CT

Hospitals 13 14

*Offices 6 6

St. Paul

Hospitals 8 11

*Offices 7 6

Edina/Bloomington

Hospitals 2 2

*Offices 7 6

* Physicians' offices and stand-alone centers

Source: Minnesota Department of Health