High-resolution CT of the cervical spine

1. High-resolution CT of a slice 1.5 mm thick is capable of demonstrating the protrusion of a cartilaginous disc on non-contrast studies. As the central disc is often associated with partial calcification, it is easily demonstrated, but this thin-section CT is indispensable for demonstrating a lateral disc. We can easily find a vacuum phenomenon of the cervical spine when the neck is hyperextended. It is important to take and to compare CTs with the patient's neck flexed and with the patient's neck extended. 2. A protruded disc is more clearly visualized by intravenous contrast agents, because the epidural plexus and granulation tissue around the disc are contrast-enhanced. Within 6 months after laminectomy, the tissue surrounding dural canal is contrast-enhanced, and it is easy to recognize the enlargement of the dural canal. It is useful that these methods can be done on outpatients. 3. As metrizamide myelo-CT can help the diagnosis of myelography, it is better for it to be done routinely after metrizamide myelography. By 1.5 mm-thick-slice CT, we can demonstrate various intraspinal structures, for example, an anterior median fissure, a posterior root, and an anterior root. It is also very useful for a postoperative check. We can conveniently use it to ascertain the relationship between the spinal cord and a vertebral body or between the nerve root and the vertebral arch. (author)