From humble beginnings in a government worker's basement 30 years ago, the Department of Veterans Affairs' Veterans Health Information Systems and Technology Architecture Imaging (VisTA) system has grown into a behemoth that supplies medical imagery to 156 VA medical centers and thousands of outside medical offices.

But while VistA is now a model for other government agencies, some VisTA components -- such as its radiology system -- must now compete with faster, better, cheaper commercial alternatives.