With the collapse of the Clinton health care reforms, advanced imaging entered an economic bubble. Between 1995 and 2006, the number of CT and MRI studies almost tripled, from 21 million to 62 million and from 9.1 to 26.6 million, respectively. The increase reflected increases in both the number of scanners and the number of scans generated per CT or MRI scanner. Without restrictions, the profits generated by CT and MR ownership inevitably spread from hospitals first to imaging centers and later to individual physicians' offices and led to potential for conflict of interest and self-referral. During this time, the increase in radiologists' efficiency was fueled by the conversion from "film" to digitized images and PACS. In conjunction with increased volume and efficiency, radiologists' compensation increased throughout the 1990s.