Utility of MRI for cervical spine clearance in blunt trauma patients after a negative CT.

PURPOSE: To determine the utility of cervical spine MRI in blunt trauma evaluation for instability after a negative non-contrast cervical spine CT.

METHODS: A review of medical records identified all adult patients with blunt trauma who underwent CT cervical spine followed by MRI within 48 h over a 33-month period. Utility of subsequent MRI was assessed in terms of findings and impact on outcome.

RESULTS: A total of 1,271 patients with blunt cervical spine trauma underwent both cervical spine CT and MRI within 48 h; 1,080 patients were included in the study analysis. Sixty-six percent of patients with a CT cervical spine study had a negative study. Of these, the subsequent cervical spine MRI had positive findings in 20.9%; 92.6% had stable ligamentous or osseous injuries, 6.0% had unstable injuries and 1.3% had potentially unstable injuries. For unstable injury, the NPV for CT was 98.5%. In all 712 patients undergoing both CT and MRI, only 1.5% had unstable injuries, and only 0.42% had significant change in management.

CONCLUSIONS: MRI for blunt trauma evaluation remains not infrequent at our institution. MRI may have utility only in certain patients with persistent abnormal neurological examination.

KEY POINTS: • MRI has limited utility after negative cervical CT in blunt trauma. • MRI is frequently positive for non-specific soft-tissue injury. • Unstable injury missed on CT is infrequent.