MRIs of the Knee: How big a role is doctor’s financial stake?

Matthew P. Lungren, MD Duke University Medical Interview with:
Matthew P. Lungren, MD
Duke University Medical Center What are the main findings of the study?

Dr. Lungren: In the single center study, knee MRIs are more likely to be normal when the referring doctor has a financial stake in the imaging center or the equipment used; these data suggest that some of these examinations may be unnecessary. Were any of the findings unexpected?

Dr. Lungren:  We certainly were curious enough to ask the question, and that is the motivation for the study in the first place, whether or not there would be a significant difference. But we were surprised that it was such a drastic difference, particularly when you take into account how we designed the study to reduce potential confounding influences.  Its important to note that this difference occurred despite otherwise highly similar pathology, demographics and referring physician characteristics between the two groups.  Again, these findings suggest that there is a different threshold for ordering MRI examinations which may be due to financial incentive What should clinicians and patients take away from your report?

Dr. Lungren:  There’s a great quote by Michael Novack that I think says it all: “Our capacity for self-deception has no known limits.”   Basically this study does raise legitimate questions:

  • Are these studies being performed unnecessarily?
  • Are these machines being over utilized because of an unconscious bias?  Patients may not want to second guess their doctor’s decision to order a scan, but it makes sense to ask whether they’re being referred to an imaging center where the doctor has a financial interest. Basically, the goal here is to be more transparent, which should be the default anytime there could be potential for violating the trust of the doctor patient relationship. What recommendations do you have for future research as a result of this study?

Dr. Lungren: We hope that this and other studies like this will capture the attention of the payors, including the government as we move toward cutting costs and eliminating waste from the health care system.  Our group supports legislative and payer driven restriction of advanced imaging equipment (CT and MRI) self-referral by clinicians, as well as mandatory formal disclosure of all financial relationships between individual ordering physicians and imaging equipment their patients are referred to, documentation of patient referral source by imaging facilities, and registration of equipment to allow payment data collection.


Lungren MP, et al “Physician self-referral: Frequency of negative findings at MR imaging of the knee as a marker of appropriate utilization” Radiology 2013; DOI: 10.1148/radiol.13130281.