Bayley J C, Kruger D M, Schlegel J M
Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota.
Spine (Phila Pa 1976). 1991 Oct;16(10 Suppl):S526-9. doi: 10.1097/00007632-199110001-00014.
Computed tomographic scanning at 0 degrees, 10 degrees, and 20 degrees was used on two human cadaver cervical spines to determine whether altering the scan angle affects spinal canal measurement. Maximum anteroposterior diameter, cross-sectional area, and transverse diameter were determined by digitization of the scans. Both spines exhibited a regular sinusoidal pattern of variation in anteroposterior diameter and cross-sectional area, with less of a pattern for transverse diameter. The maximum values occurred around the discs in the normal spine, moving to just below the pedicle in the spondylotic spine. Minimum values were at the pedicle in the normal spine and near the discs in the spondylotic spine. Changing the computed tomographic scan angle to 10 degrees in either a cephalad or caudad direction had a negligible effect on the pattern or absolute values for any dimension in either spine. Changing the angle to 20 degrees in either direction significantly and irregularly altered both the pattern and values of anteroposterior diameter and cross-sectional area in both spines. There was little effect on transverse diameter. It was concluded that comparison of different scans should be interpreted with caution unless the change in angulation is 10 degrees or less.
对两具人类尸体颈椎进行了0度、10度和20度的计算机断层扫描，以确定改变扫描角度是否会影响椎管测量。通过扫描数字化确定最大前后径、横截面积和横径。两具脊柱的前后径和横截面积均呈现规则的正弦变化模式，横径的模式则不太明显。正常脊柱中最大值出现在椎间盘周围，在脊柱关节病脊柱中则移至椎弓根下方。正常脊柱中最小值位于椎弓根处，脊柱关节病脊柱中则靠近椎间盘。将计算机断层扫描角度向头侧或尾侧改变10度，对两具脊柱中任何维度的模式或绝对值影响可忽略不计。向任一方向将角度改变至20度会显著且不规则地改变两具脊柱前后径和横截面积的模式及数值。对横径影响不大。得出的结论是，除非角度变化为10度或更小，否则不同扫描结果的比较应谨慎解释。
