A new Yale-led study finds that the cost of a follow-up MRI after a normal CT scan for unconscious patients with blunt neck injuries may outweigh the benefit.

Individuals who suffer injury to the back of the neck, or cervical spine, after a car accident, serious fall, or other blunt trauma typically receive a CT scan. If that test is negative for bone fracture, clinicians often follow up with an MRI to check for damage to ligaments. Ligament injury might imply instability, which if not fixed, could potentially lead to spinal cord injury. However, in recent years, the utility of routine MRIs for these injuries has come into question.

Senior study author Ajay Malhotra, MD, and his colleagues conducted an analysis based on published patient data. They found that the average cost of the follow-up MRI was $14,185 and that there was no difference in health benefits, as measured in “quality of life” years, for patients who had the test vs those who didn’t, the researchers noted.

The study results may be explained in part by the frequency of false-positive results from MRIs. The findings, published in JAMA Surgery, could be informative for emergency care physicians and health-care policymakers, said Malhotra.