Is magnetic resonance imaging essential in clearing the cervical spine in obtunded patients with blunt trauma?

Background: The optimal method of clearing the cervical spine (CS) in obtunded blunt trauma patients (OBTPs) remains unclear. Computed tomography (CT) identifies most injuries but may fail to detect ligamentous and spinal cord injuries. Magnetic resonance (MR) imaging has been widely used to exclude these. The purpose of this study was to evaluate whether CT of the CS (CT-CS) alone is adequate to clear the CS in OBTPs. Our hypothesis was that MR imaging of the CS (MR-CS) does not contribute relevant information and is not necessary in this patient population.
Methods: A prospective evaluation of OBTPs with a CT-CS negative for acute trauma and an MR-CS obtained for clearance was performed at a Level I trauma center between July 1, 2004, and June 30, 2006. Data gathered included demographics, results of CT-CS and MR-CS, timing of MR-CS, Glasgow Coma Scale score at time of MR-CS, adverse events occurring while obtaining MR-CS, and cervical collar complications.
Results: One hundred and fifteen patients were identified. There were 90 male patients. The mean age was 43.9 years +/- 1.9 years, mean Injury Severity Score was 24.4 +/- 1.0, and mean length of stay was 23.4 days +/- 1.2 days. The MR-CS was performed on hospital day 7.5 +/- 0.6 and the mean Glasgow Coma Scale score at the time of MR-CS was 8.3 +/- 0.3. Six MR-CS (5.2%) subsequently identified acute injuries. Findings included microtrabecular injuries, intraspinous ligament injuries, a cord signal abnormality, and a cervical epidural hematoma. None of these findings changed management and none required continued cervical collar usage. Six cervical collar complications were identified (5.2%). No adverse events related to transport or obtaining MR-CS occurred. Eliminating MR-CS would have decreased health care costs by over $250,000 during this period.
Conclusions: MR-CS may be unnecessary in the OBTP if the CT-CS is negative. Elimination of MR-CS in this population will lead to earlier removal of cervical collars, decreased cervical collar complications, protection of the patient from exposure to potential risks inherent to obtaining this study, and decreased health care costs.