Housing imaging and surgical services under one roof would appear to be a good match. While industry observers note that imaging is a growth field rivaling surgery, they caution that an MRI system is a major investment - scanners begin at $800,000 and you'll need to schedule enough patients to earn back the costs - and you'll have to tiptoe around thorny government regulations. Whether you're considering adding an MRI now or might do so down the road, here's a look at what you need to consider.