胸椎黄韧带骨化的影像学研究及其临床意义

Imaging study of the ossification of thoracic ligamentum flavum

目的:探讨胸椎黄韧带骨化的影像学表现,评价X线、CT和MRI的诊断价值。方法:回顾性分析23例经手术病理证实的胸椎黄韧带骨化的X线、CT和MRI影像学资料。结果:所有病例的X线平片显示胸椎退行性改变,仅其中3例的侧位片显示椎间孔处模糊骨化影。CT扫描显示胸椎椎板前缘凸向椎管的高密度影,椎管变窄,外侧型7例,弥漫型8例,结节增厚型8例。MRI显示黄韧带骨化病变呈低信号影,脊髓不同程度受压。23例患者共发现黄韧带骨化节段57个,骨化节段为单发病灶6例,多发病灶17例。病变累及上胸段(T1～4)3例,中胸段(T5～8)7例,下胸段(T9～12)16例。合并后纵韧带骨化6例,合并胸椎间盘突出2例。结论:胸椎黄韧带骨化有典型的CT和MRI影像学表现,但在X线平片上容易漏诊;CT结合MRI检查是确诊胸椎黄韧带骨化的重要诊断手段。

Objcetive： To investigate the imaging characteristics of the ossification of thoracic ligamentum flavum （OTLF）and evaluate the diagnostic value of X-ray film, CT and MRI in OTLF. Methods： A total of 23 cases with OTLF confirmed by pathology were included in this study. The imaging data of X-ray film, CT and MRI were retrospectively analyzed. Results： In the X-ray film, the degenerative changes of thoracic vertebrae were identified in all cases, but only 3 cases had the vague ossification image at the foramens in the lateral X-ray film. CT scanning demonstrated the high density of the ossific changes with a sharp projection from lamina to spinal canal, causing thoracic spinal canal stenosis. The types of OTLF were a lateral type in 7 patients, diffuse in 8, and thickened nodular in 8. MRI images on both T1WI and T1WI showed low signal intensity of the OTLF and the associated compression of spinal cord. There were 57 levels of OTLF in 23 patients including 6 in single-level and 17 in multilevel. OTLF involved the upper thoracic spine （T1-4） in 3 cases, midthoracic spine （T5-8） in 7 cases, lower thoracic spine （T9-12） in 16 cases. In addition, there were 6 patients associated with ossification of the posterior longitudinal ligament and 2 cases with thoracic disc herniation. Conclusions： OTLF have the typical CT and MRI appearances, but it was apt to be overlooked on an x-ray film. OTLF can be precisely diagnosed by the combination of CT and MRI with regard to information on the ossification, the degree of thoracic spinal stenosis and the associated spinal cord compression.