Researchers including one of Indian–origin have found that patients whose doctors own MRI machines are more likely to get scans they might not need as compared to those who have no financial interests.

Researchers analysed reports on 500 MRI scans performed on patients with lower back pain that had been sent for review to Duke University. Of the scans with normal results, 106 were ordered by orthopedic surgeons who owned the machines versus 57 by doctors without financial ties.

The normal scans accounted for about half of those ordered by surgeons with financial connections, compared with about a quarter in the other group. The authors only examined the scans, so there’s no information on the patients’ medical history or outcome.

According to Ramsey Kilani, a radiology instructor at Duke University and co-author of the study, the results suggest that some doctors who own MRI scanners use them excessively on patients who probably don’t need them, to help pay for the expensive equipment and make a profit.

“Once you own a scanner, you have an incentive to run it 24 hours a day,” CBS News quoted Kilani as saying.

The study was presented at the Radiological Society of North America meeting in Chicago.