脊柱关节突交锁螺旋CT的多平面重建和三维重建

Analysis and discussion on the facet of the spinal column, spiral CT lock multiplanar reconstruction and 3D reconstruction

目的:探讨脊柱椎关节突交锁螺旋CT的多平面重建(multiplanar reconstruction,MPR)和三维(three dimension,3D)重建图像的特点及在诊断中的作用。方法:选取本院近年来31例诊断为脊柱椎关节突交锁的患者,回顾性分析其术前或牵引前的螺旋CT资料,同时进行MPR和3D图像重建;观察关节突交锁在轴位、MPR和3D重建的螺旋CT表现,并评估轴位、MPR和3D重建图像的优势。结果:31例患者影像中,轴位上呈现'反汉堡包'征者,颈椎损伤21例、胸腰段损伤10例。MPR矢状面显示下关节突与下方椎体上关节突形成顶对顶形态,伴有患椎I°前滑脱及下关节突尖端骨折颈椎5例,胸腰段0例,均为单侧交锁;上方椎体下关节突越过下方椎体上关节突前移,形成背靠背形态,伴有患椎II°~III°前滑脱,以双侧交锁为主,颈椎双侧9例、单侧6例,胸腰段双侧10例,并伴有下方椎体屈曲性泪滴样骨折,颈椎7例、胸腰段3例;一侧上、下关节突成背靠背形态,一侧上、下关节突成顶对顶形态,颈椎1例。冠状面,颈椎21例下关节突不同程度内移,与下方椎体上关节突呈互相依托,或下关节突锁于上关节凹内;胸腰段10例下关节突与上关节突同时出现或显示下关节突明显上移,关节结构消失。3D重建图像清楚显示31例关节突交锁,并通过不同面及不同角度旋转显示关节突交锁的空间形态,并可清晰地显示椎体滑脱及旋转程度。结论:MPR及3D重建显示关节突交锁较轴位清楚、直观。脊柱关节突交锁的螺旋CT的MPR和3D重建是轴位CT扫描有意义的补充,有助于本病的诊断,减少漏诊,为临床诊疗提供了有价值的影像信息。

Objective: To investigate the imaging appearances and diagnostic value of axial CT scanning, spiral CT multiplanar reconstruction(MPR) and three-dimensional(3D) reconstruction in vertebral facet joints locking.Methods: A total of 31 cases of vertebral facet joints locking, with injuries in different parts, wererecruited to explore their CT features, and to evaluate their advantages in diagnosis against each other.Results: Among the CT images of 31 cases with 'Hamburger' sign in axial view, there were 21 cases of cervical spine and 10 cases of thoracolumbar segment; in vertical plane of MPR, 'top to top' form was formed belowthe inferior and the superior articular process, accompanied by I° spondylolisthesis and inferior articular process tip fracture; 5 cases were unilateral locked cervical spine; none case for thoracolumbar segment. The inferior articular process was crossed with the superior articular process belowand moved forward, formed 'back to back' form, accompanied by II°–III° spondylolisthesis. 9 or 6 cases were bilateral or unilateral locking cervical spine, 10 cases were thoracolumbar segment, accompanied by teardrop fracture in the vertebral body belowcervical spine. In coronal plane of MPR, inferior articular process showed ingression in different extent, and relied on the superior articular process belowor locked in the articular fossa(21 cases for cervical spine); inferior articular process displayed upward displacement or appeared with the superior articular process at the same time, which meant joint structure disappearing thoracolumbar segment(10 cases). In 3D reconstruction, 31 cases displayed clearly in the spatial form of vertebral facet joints locking and the degree of spondylolisthesis of vertebral body.Conclusion: MPR and 3D image were more clear and intuitive in vertebral facet joints locking comparing to axial CT scan image. Spiral CT MPR and 3D reconstruction contributed to the diagnosis of vertebral facet joints locking and the reduction of misdiagnoses rates.