CHAPTER 8: Imaging the Cervical Spine

1. INTRODUCTION: FAST CERVICAL SPINE FACTS

❑ Traumatic Injuries

• Injuries to the cervical spine are classified as stable or unstable injuries, with respect to the immediate or potential risk to the spinal cord and nerve roots.

• Stable injures have intact posterior spinal ligaments (e.g., compression fractures, disk herniation, unilateral facet dislocations).

• Unstable injuries show displacement (e.g., fracture–dislocations, bilateral facet dislocations).

• C1–C2 and C6–C7 are the most frequently injured levels in the cervical spine.

• Adults characteristically injure the lower cervical spine levels.

• Children more frequently injure the upper cervical spine levels.

• SCIWORA is an acronym for spinal cord injury without radiographic abnormalities. This is predominant in children owing to the inherent elasticity in the pediatric spine.

❑ Degenerative Diseases

• Degenerative Disk Disease (DDD) presents on radiograph in most persons older than 60 years. Changes in the disk include dehydration, nuclear herniation, annular protrusion, and fibrous replacement of the annulus, all of which result in decrease in disk height, vertebral endplate approximation, and uncovertebral joint friction, which leads to osteophyte formation around the entire osseous margin of the endplates.

• Degenerative Joint Disease (DJD) is osteoarthritic changes of the facet joints. As in DJD elsewhere in the body, facets undergo articular cartilage thinning, subchondral bone sclerosis, eburnation, and development of osteophytes at joint margins. Cervical spine DJD may develop in isolation or concomitantly with DDD. One process often accelerates the development of the other process.

• Foraminal encroachment results from degenerative changes in adjacent structures, including DDD and DJD, that diminish the size of the intervertebral foramina. The spinal nerve root that exits through this constricted foramen is susceptible to mechanical compression. The resultant radiating arm pain brings the patient to seek medical attention.

• Spondylosis is the formation of osteophytes in response to DDD, but before there is obvious disk space narrowing. Osteophyte formation has been shown to be most predominant at C4–C5 and C5–C6, as a result of greater segmental mobility at these levels.

❑ The Imaging Choices

• Radiographs are the initial imaging study for cervical spine problems, with the exception of high-risk trauma patients, who are evaluated by CT. However, if CT is not available, radiographs are indicated. Radiographs adequately demonstrate most significant fractures and dislocations, as well as nontraumatic disorders such as the various arthritides.

• Computed tomography (CT) is the initial imaging study for high-risk trauma patients as it is the most sensitive and time-efficient imaging modality in a trauma setting. One scanning examination can evaluate for multi-system trauma: the head CT for the brain, the thoracic-abdominal-pelvic (TAP) scan for the viscera, and, finally, all images of the spine can be derived from this initial data set.

• Magnetic resonance imaging (MRI) is the study of choice for the evaluation of spinal cord, ligaments, soft tissues, and neurological deficits not ...