The standard practice of obtaining cervical spine radiographs in all patients who have sustained substantial blunt cervical trauma has raised concerns about overuse of a diagnostic modality that is only positive in approximately 2 to 5 percent of such patients. The role of magnetic resonance imaging (MRI) in the evaluation of cervical spine trauma has not been clarified. Katzberg and associates conducted a prospective study to compare the utility of conventional radiographic assessment and MRI in patients presenting to an emergency department with suspected cervical spinal injuries.
The study included 199 patients who were evaluated at a level 1 trauma center. In 98 (49.2 percent) of the patients, trauma was the result of motor vehicle crashes. Cervical spine MRI was performed as soon as possible after initial conventional radiographs were obtained. The study was divided into two phases: an initial phase that consisted of a nonselective assessment of 101 patients and a second phase that consisted of selective assessment of 98 patients who had an increased likelihood of cervical spine trauma on the basis of neurologic deficits, substantial neck pain or other abnormal findings.
Acute cervical spine fractures were present in 3 percent (three patients) of the 101 patients in the initial phase of the study, compared with 11.2 percent (11 patients) of the 98 patients in the second phase. Similarly, patients in the selective assessment phase more commonly had other abnormal findings, such as facet subluxation or dislocation, prevertebral hemorrhage, anterior longitudinal ligament damage, traumatic disc herniation and cord compression.
Overall, 58 patients were found to have one or more acute cervical spine injuries of any type. MRI studies were positive in 50 (86 percent) of these patients, and conventional radiographs were positive in 44 (76 percent) of them. Of the 172 acute injuries in these 58 patients, 136 (79 percent) were demonstrated by MRI. In contrast, conventional radiographs demonstrated 39 (23 percent) of the injuries. The majority of the 36 injuries not detectable by MRI were skeletal abnormalities, including acute fracture, facet subluxation and vertebral subluxation. These injuries were visualized on conventional radiographs or computed tomography.
The findings revealed that MRI and conventional radiography had comparable utility in the diagnosis of acute cervical spine fracture. However, MRI was superior to conventional radiography in the diagnosis of vertebral hemorrhage or edema, anterior and posterior ligamentous injury, traumatic disk herniation, cord edema and cord compression. There were no untoward events or injuries from the use of MRI in the trauma setting.
The authors conclude that MRI provides an accurate assessment of soft tissue injury of the cervical spine. Such injuries may be missed on conventional radiography. Although MRI may be perceived as incompatible with clinical assessment and the intensive monitoring requirements of the acute trauma setting, this study demonstrates the usefulness of MRI in the evaluation of patients with sustained cervical trauma. The authors believe MRI should be strongly considered in the early evaluation of cervical spine injury.