Ramsey Kilani, MD, and colleagues analyzed estimates in the medical literature of increased likelihood of imaging by self-referrers compared to colleagues who have no financial interest in imaging. The group also reviewed Medicare Part B total imaging expenditures and studied related components of Medicare Part B imaging spending.

During the period between 2000 and 2006, Medicare imaging expenditure increased from $6.8 billion to $14.1 billion, they found. Of the $14.1 billion spent on imaging in 2006, $9 billion, or 64%, was to physician offices, while between $4.9 billion and $6.1 billion went to nonradiologists.

In addition, the self-referral data the team examined showed that nonradiologist self-referrers of medical imaging were 1.2 to 11 times more likely to order imaging than clinicians who had no financial interest in imaging.