Earlier this week, 9 medical societies put out a paper that suggest the elimination or reduction of a large number of medical procedures. See for example http://www.nytimes.com/2012/04/04/health/doctor-panels-urge-fewer-routine-tests.html?ref=health
I believe the Affordable Care Act has many provisions to encourage reduction of unnecessary procedures. One of them is vlaue based purchased in which physicians, hospitals, nursing homes, etc are paid based on quality of care measures rather than the amount of services provided which had been the payment system in the past. This will go along way to addressing this issue.
Another way is the creation of accountable care organizations which will create the integration of different components of the delivery system. This integration can lead to greater review by the different components to review the unnecessary use of services.
The comparative effectiveness review system can add further weight to the recommendations from the above medical organizations.
The greater use of electronic medical records can be programmed to alert when these unnecessary procedures are performed.
The IPAB (Independent Payment Advisory Board) can play a role in making decisions based on these recommendations.
These are just a few of the ways that ACA can play a role. There are likely to be additional provisions if I study this more, but these are a few off the top of my head.