Inclusion Criteria:  100 patients (50 men and 50 women aged 20 to 70 years old) who visited our hospital and underwent both cervical CT and MRI simultaneously  Exclusion Criteria:  patients who had a history of cervical spine surgery or cervical cord edema, whose CT or MR images did not include all the cervical vertebrae from C3 to T1, patients who had at least one missing medical detail such as diagnosis, age, height, or weight.