The normal value of the sagittal diameter of the cervical spinal canal in normal adults varies from segment to segment and is usually smaller in women than in men by about 1-2 mm. In the entire cervical spine, the diameter of cervical 2 is about 25 mm and can be up to 30 mm. cervical 1 corresponds to a normal value of 16-24 mm, while the sagittal diameter of the spinal canal of cervical 3-7 is relatively small, with a normal value of 13-19 mm, and the difference in size between the adjacent vertebrae corresponds to a spinal canal of no more than 2 mm. The size of the spinal canal is measured clinically, mainly by CT or MRI of the cervical spine. Once the spinal canal becomes narrow, the spinal cord or adjacent nerve roots will be compressed. This can cause irreversible damage such as ischemia and liquefaction of the spinal cord over time. Therefore, once the manifestation of cervical spinal stenosis is detected, treatment should be actively carried out to release the compression and relieve the symptoms.