伴有椎动脉优势的下颈椎椎弓根形态学的CT观察

Cervical pedicle accompanied vertebral artery dominance： morphometric measurement of cervical pedicle and its surrounding structure using 3D-CT

中文关键词:  椎动脉优势  椎弓根  形态学

英文关键词:Vertebral artery dominance  Cervical pedicle  Morphology

中文摘要:

  【摘要】 目的：观察存在椎动脉优势（一侧直径较对侧大0.8mm以上）的下颈椎椎弓根的形态学特点，探讨其对椎弓根螺钉置钉的影响。方法：回顾性分析我科2016年1月1日~2017年7月1日因颈椎疾患行椎动脉CT造影（CT angiography，CTA）患者的影像学资料。在CT三维重建上测量椎动脉直径（vertebral artery diameter，VAD），将存在椎动脉优势患者纳入研究，VAD较大的一侧为椎动脉优势侧，较小的一侧分为椎动脉非优势侧。共纳入存在椎动脉优势患者68例。其中男42例，女26例，年龄12~81岁，平均56.3±13.0岁。在CT三维重建上测量C3~C6椎体双侧的以下参数：VAD、椎弓根宽度（pedicle outer width，POW）、椎弓根外侧壁到椎动脉内侧距离（lateral pedicle border to vertebral artery，LPVA）、横突孔面积（area of transverse foramen，ATF），并计算：椎动脉横截面积（area of vertebral artery，AVA）=π×（VAD/2）2；横突孔占用率（occupation ratio of transverse foramen，ORTF）=AVA/ATF。比较优势侧与非优各参数的差异，分析与椎动脉优势的相关性；统计双侧POW<4mm比例，并纵向比较优势侧各椎体参数差异，判断椎弓根螺钉置钉风险。结果：存在椎动脉优势患者中，左侧优势占75%，右侧优势占25%。VAD优势侧平均为3.78±0.49mm，非优势侧为2.29±0.53mm；POW优势侧宽度为5.07±0.98mm，非优势侧为5.46±0.94mm，LPVA优势侧与非优势侧分别为1.04±0.50mm和1.18±0.56mm，ATF优势侧与非优势侧分别为29.00±6.87mm2和20.41±5.40mm2，ORTF优势侧与非优势侧分别为（40.5±8.5）%和（22.6±8.9）%。优势侧与非优势侧相比，POW、LPVA及ATF、ORTF存在统计学差异（P<0.05）。POW<4mm的比例优势侧与非优势侧分别为9.9%和4%。优势侧纵向对比，各参数在C3、C4较小，C5、C6较大。结论：椎动脉优势侧POW、LPVA小于非优势侧，POW<4mm的比例及ORTF大于非优势侧，优势侧椎弓根螺钉置钉风险高于非优势侧。

英文摘要:

  【Abstract】 Objectives： The purpose of this retrospective study was to observe the morphometric characteristics of lower cervical pedicles with dominant vertebral artery(vertebral artery diameter in one side is at least 0.8mm larger than contralateral side) and its surrounding structure，analyze the influence to cervical pedicle screw(CPS) implantation. Methods: 166 consecutive patients who underwent cervical 3D-CT angiography were enrolled in this study. Patients who had dominant artery(difference of ≥0.8mm between the widths of two vertebral artery) were selected to perform the measurements. The measurements included long axis diameter of the VA, short axis of the VA, pedicle outer width(POW), lateral pedicle border to vertebral artery(LPVA) and area of transverse foramen(ATF). Vertebral artery diameter (VAD)= (long axis diameter of the VA+short axis of the VA)/2, area of VA（AVA）=π×(VAD/2)2 residuary area of transverse foramen(RATF)=ATF-AVA. Occupation ratio of transverse foramen(ORTF)=AVA/ATF. Differences of all parameters between the two were analyzed. Results: The proportion of left VA dominance was 75% and 25% of the right. The mean VAD of dominant side was 3.78±0.49mm, which was 2.29±0.53mm of nondominant side. POW of dominant side and non-dominant side was 5.1±1.0mm and 5.5±0.9mm,LPVA was 1.0±0.5mm and 1.2±0.6mm; ATF was 29.0±6.9mm2 and 20.4±5.4mm2; ORTF was (40.5±8.5)% and (22.6±8.9)%, respectively. Parameters comparison between the two sides: POW, LPVA of dominant side was smaller than non-dominant side, ATF and ORTF was opposite, these results was statistically significant (P<0.05). The Pearson correlation coefficient between POW and VAD was -0.094, ATF and VAD was 0.549(P<0.05), showing positive correlation between ATF and VAD, but negative correlation between POW and VAD. The proportion of POW<4mm in VA dominant side was higher than non-dominant side. C3 has the most high rate(19.1%) and decrease caudally. Vertical comparison among dominant side shows all parameters were lower at C3, C4 but increase slightly at C5, C6. Conclusions: POW and LPVA of dominant side is smaller than those of nondominant side, ORTF and the ratio of POW<4mm are higher in dominant side， the risk of CPS implantation is higher in dominant side.