MRI May Not Be Necessary in Cervical Spine Trauma if CT Is Normal

Patients with cervical spine injuries can be cleared on the basis of normal computed tomography (CT) alone without also undergoing magnetic resonance imaging (MRI) if they are alert and have normal motor examination results, according to investigators whose findings were published in the August 2005 issue of the Archives of Surgery.
"This study evaluated all cervical MRIs in trauma patients without motor deficits and with normal CT results of the cervical spine," Rob Schuster, MD, and colleagues wrote. "We found that none of these patients had clinically significant injuries diagnosed by MRI. We also observed these patients clinically and found that no patient experienced neurologic deterioration." Even among comatose patients, "movement of the extremities ... Is sufficient motor activity to rule out spinal cord injury when the CT scan result is normal."

Dr. Schuster is affiliated with the department of surgery at the Santa Barbara Cottage Hospital in Santa Barbara, California.

The investigative team determined if cervical spine injuries could be ruled out with a normal CT alone in patients who have had sustained blunt trauma. Therefore, they prospectively gathered data on 2,854 trauma patients who were admitted to the hospital. Among these patients, 91.2% had blunt trauma, and among blunt trauma patients, 56.2% sustained a closed head injury. Among those admitted, 100 patients had a cervical spine injury, a spinal cord injury, or both. The treating physicians diagnosed 85 of the cervical spine injuries on the basis of CT results. Within the group of cervical spine injury, 15 had neurologic deficits that were not detected on CT, and among these, seven had soft-tissue abnormalities that were detected on MRI.

The investigators also assessed the MRIs of 93 patients who had a normal admission motor examination result, a negative CT result for trauma, and persistent cervical spine pain. Among these patients, all had MRI findings that were negative for clinically significant injury. The MRI showed degenerative disc disease in 17 and spinal canal stenosis secondary to ossification in six.

Among the 12 comatose patients, defined as a Glasgow Coma Scale (GCS) score of less than 9, all were able to move all four extremities when they were admitted. All had normal CT results of the cervical spine. These patients' subsequent MRI results were all negative for injury.

Among the patients with normal CT results, none had neurologic deterioration, and none required surgery for spinal injury, the authors wrote.

Arch Surg. 2005;140:762-766

Learning Objectives for This Educational Activity

Upon completion of this activity, participants will be able to:

• Describe the criteria for clearing the cervical spine in trauma patients.
  
• Explain why trauma patients with normal motor examination results and normal cervical CT scan do not need additional MRI studies to clear the cervical spine.
  

Clinical Context

Cervical spine injuries can lead to devastating neurologic deficits; therefore, accurate and rapid diagnosis and treatment is essential in trauma situations. To clinically clear the cervical spine, the physician must make certain the patient is awake, alert, and lucid and has a normal neurologic examination and no neck pain. All other patients who do not meet these criteria must undergo radiologic examination before the spine is cleared. Studies have found that plain radiographs alone miss 46% of injuries and are not adequate in clearing the spine.

CT of the cervical spine has increased the rate of injury detection and decreased the rate of missed injury. One study demonstrated that CT with sagittal reconstructions showed a sensitivity of 99% and specificity of 100% in detecting cervical spine injury. Therefore, cervical CT scans have become the mainstay in clearing the spine.

However, there are two populations of patients that may challenge the use of CT-based protocol, requiring a more extensive imaging study such as a MRI. There are concerns that patients with persistent neck pain and comatose patients may have a ligamentous injury. The current authors of this prospective study show that this type of injury is unlikely and would manifest as a neurologic deficit at the time of initial trauma. Further, in this study population, the authors note that clinically significant injuries would not be found. Hence, additional studies beyond a CT scan would not be needed to clear the cervical spine.

Study Highlights

• Between January 1999 to December 2003, 2,854 trauma patients at Santa Barbara Cottage Hospital were evaluated in this prospective study.
  
• 91.2% had blunt trauma, and of these, 56.2% had a closed head injury.
  
• The mean age was 37 years, and the Male-female proportion was 69.4% to 30.6%.
  
• Cervical spine protocol was implemented in all patients with evidence of blunt trauma. The cervical spine was clinically cleared with negative findings from the physical examination. However, for those who could not be cleared clinically, helical CT scanning was performed, and of those, selected patients had a MRI done.
  
• To measure neurologic outcomes, all patients had frequent neurologic examinations and outpatient follow-up in the clinic 1 to 2 weeks after discharge.
  
• 100 patients (3.8%) of all blunt trauma admissions had cervical spine and/or spinal cord injuries as evidenced by fracture and/or peripheral neurologic deficits. 85 patients had a cervical spine injury diagnosed by CT, and 15 patients had neurologic deficits without CT findings.
  
• 93 patients had a normal motor examination result, a negative CT result for trauma, and severe persistent cervical spine pain. They were all examined with MRI, and all results were negative for clinically significant injury.
  
• 12 comatose patients with a GCS score of less than 9, ability to move all 4 extremities on arrival, and with normal CT results of the cervical spine had negative MRI examination results.
  
• None of the patients experienced neurologic deterioration, and no patient required operative management of spinal injury.
  
• Blunt trauma patients with normal motor examination results and normal CT results of the cervical spine do not need further radiologic examination such as a MRI before clearing the spine.

Pearls for Practice

• To clinically clear the spine, the physician must make certain that the patient is awake, alert, and lucid and has a normal neurologic examination and no neck pain.
  
• There was no additional benefit or information gained in using MRI in blunt trauma patients with normal motor examination and normal CT results before clearing the spine.
  

Saludos Cordiales
Dr. José Manuel Ferrer