PACS在颈椎后方结构测量及其临床意义

Clinical significance of PACS on the measurement of posterior cervical structures

目的利用图像存储传输系统(PACS)结合CT片测量颈椎后方解剖学结构,为临床颈椎椎弓根置钉提供资料。方法利用PACS结合CT片,由5名脊柱外科医师对2000例正常人颈椎椎弓根的矢状位及横断为进行精确测量,得出椎弓根的长度、宽度、高度、向内侧倾斜、向头、尾侧倾斜角度的数据值,并分别计算各节段左右侧椎弓根测量值的均值和标准差,进行统计学分析。结果寰椎入钉点距离一般在后弓中点旁开17～20mm,在C2～7各椎弓根均有髓腔,C2～7椎弓根的高度大于宽度,C3、C4椎弓根直径最小,仍可置入3.5mm的螺钉。寰枢椎螺钉在矢状面入钉角向头侧倾斜为正角,下颈椎螺钉向尾侧倾斜为负角,C4接近水平,C5～7负角逐渐增大,C7可达-19°左右。在横断位上测量的椎弓根的进钉角度显示,其中C2最小,下颈椎椎弓根具有变异性,术前利用CT片通过PACS进行精确测量,指导术中准确选钉与安全置钉具有指导性意义。结论应用PACS系统结合CT片术前测量,能够指导术中安全置入颈椎椎弓根螺钉,明显减少并发症,是一种值得推广的方法。

Objective To measure posterior cervical structures adopting the picture archiving and communication system（PACS） combined with CT,and provide anatomic data for the cervical pedicle screws placement.Methods Adopting PACS combined with CT skill,the sagittal and transverse slices through the neck of cervical vertebral arch from 2000 cases of the normal adults were measured precisely by 5 spinal surgeons separately.The mean values and standard deviations of the pedicle length,width,height,introversion angle,anteversion angle,and retroversion angle,at the different levels,were collected and statistically analyzed.Results The screw entry-point of atlas was at the midpoint of posterior arch about 17～20 mm laterally.The marrow cavities appeared from C2 to C7 pedicles,and the pedicle heights were more extensive than the pedicle widths from C2 to C7.3.5 mm screws can be placed into pedicle arches of C3 and C4,despite of their smallest diameters.On the sagittal plane,the superior cervical screw should be tilted cranially,however,inferior cervical screws tilted caudally,with the C4 angle of horizontal direction,C5～7 angles of increasing,and C7 of about-19°.On the transverse planes,screw entry angle of C2 was the smallest,however,inferior entry screw angles were more variable.Conclusions Application of PACS system combined with CT images,the cervical pedicle screws can be inserted more safely,with no complications happened.