腰椎椎弓根CT影像学参数的测量与临床意义

Measurement and clinical significance of lumbar pedicle CT imaging parameters

背景:尽管随着技术的发展,越来越多精确、个性化的检测和辅助工具应用于骨科领域,但是目前术前CT依然是众多骨科医师的一线检查手段。因此掌握腰椎椎弓根的CT影像学表现是脊柱外科医生的基础,也是脊柱置钉手术的基石。目的:通过CT影像技术,测量国人腰椎椎弓根影像学参数,了解其内部结构规律作为螺钉选择的依据,以提高置钉手术的安全性与准确性。方法:随机选择36例于苏州大学第一附属医院行腰椎及腹腔CT检查但无腰椎相关疾病的病例,其中男20例,女16例,年龄(43.3±12.3)岁。应用PACS系统进行腰椎重建,测量相关影像学参数。结果与结论:(1)病例自身左右两侧椎弓根各参数进行配对样本t检验,差异均无显著性意义(P>0.05);(2)腰椎椎弓根上倾角总体呈下降趋势,变化水平较小,L_4相对L_3增大些,L_5水平最小,平均为-1.3°;外倾角相反呈逐渐增大趋势,L_5处最大,均数为25.4°;(3)椎弓根通道长度在腰椎节段先增大后减小,在L_2节段最长平均52.2 mm,L_5最短,平均47.4 mm;(4)椎弓根高度在L_1-L_3水平略有缩小,最小15.4 mm(L3均数),后至L_5达到最大,可达22.7 mm(L_5均数);松质骨高度也呈相同趋势,最小L_3为10.2 mm,最大L_5为17.9 mm;(5)腰椎椎弓根宽度呈上升趋势,L_1最小为7.7 mm,L_5最大为12.5 mm;松质骨宽度也成相似上升趋势,最窄L_1平均为4.9 mm,最大L_5平均为8.5 mm;(6)总体上看,上腰椎椎弓根通道细长,而下腰椎稍粗短;(7)综上,通过对椎弓根形态参数的测量,其相关参数可以成为选择合适螺钉的依据。同时,腰椎各节段椎弓根形态具有一定差异也存在一定规律,准确把握其结构与影像特点是椎弓根螺钉置钉手术的基础。而术前影像资料的收集评估,结合患者一般情况,制定个性化的置钉方案,在提高置钉的安全性和准确性方面有所帮助。

BACKGROUND:Although more and more accurate and personalized detection and assistive tools are used in the field of orthopedics with the development of technology,the preoperative CT is still the first-line examination choice of many orthopedic surgeons.Therefore,to master the lumbar spine CT imaging performance is not only the basis of spine surgeons,but also the cornerstone of spinal nail surgery.OBJECTIVE:Through CT imaging technique,we measured the parameters of lumbar pedicle imaging,and understood its internal structure as the basis for the choice of screws,in order to improve the safety and accuracy of nail surgery.METHODS:Totally 36 cases without lumbar vertebrae-related disease undergoing lumbar vertebra and abdominal cavity CT scan were randomly selected,including 20 males and 16 females at the age of(43.3±12.3)years.PACS was used to reconstruct lumbar vertebrae,and the related imaging parameters were measured.RESULTS AND CONCLUSION:(1)There was no significant difference between the left and right sides of the pedicle for paired t-test(P>0.05).(2)Pedicle sagittal angle had downward trend,the level of change was small;L4 increased relative to L3;L5 level was minimum at the average of-1.3°.Pedicle transverse angle had gradually increased trend,and maximum at L5;the average was 25.4°.(3)The length of the pedicle channel increased first and then decreased in the lumbar segment;the longest average was 52.2 mm in the L2 segment,the shortest at L5,with an average of 47.4 mm.(4)The pedicle height was slightly narrowed at L1-L3 levels;the smallest was 15.4 mm(L3 mean),and reached the maximum in the L5 at 22.7 mm(L5 mean).Cancellous bone height also showed the same trend,the minimum in the L3 at 10.2 mm,the maximum in the L5 at 17.9 mm.(5)Lumbar pedicle width showed an upward trend,L1 minimum of 7.7 mm,L5 maximum of 12.5 mm.Cancellous bone width also became a similar upward trend;the narrowest L1,averagely 4.9 mm;the maximum L5,averagely 8.5 mm.(6)Overall,the upper lumbar pedicle channel was slender,while the lower lumbar spine was slightly short.(7)The parameters of the pedicle can be used as the basis for selecting the appropriate screw.At the same time,lumbar pedicle morphology has a certain difference,and there is a certain law.Accurately grasping its structure and image characteristics of pedicle screw fixation is the basis of surgery.The preoperative imaging data collection and assessment,combined with the general situation of patients,and the development of personalized programming,will help in improving the safety and accuracy of screw placement.