胸椎黄韧带骨化合并硬膜囊骨化的影像学特征和病理学表现

摘要

Objective To investigate the imaging characteristics and pathogenic manifestations of thoracic ossification of the ligamentum flavum complicated with dural ossification.Methods CT and MRI imaging data of 62 segments from 29 patients with thoracic ossification of the ligamentum flavum (TOLF) treated with "en bloc resection of lamina and ossified mass" were retrospectively analyzed.There were 19 males and 10 females,aged 54.9±10.25 years (36-77 years),16 segments in 11 cases with dural ossification (DO) and 46 segments in 18 cases without DO.The ossified mass shape,the relationship between ossified mas and dura mater on cross section of CT bone window and MRI T2WI,and the ossified mass occupational rate (OR) of the spinal canal were investigated.Pathologic features of TOLF-DO from 2 patients were analyzed by H&E staining.Results The shape of ossified mass was as followed,in 16 segments with DO,7 segments (43.8％) by CT and 2 segments (12.5％) by MRI showing ossification layer on the dural sac side of ligamentum flavum;1 segment (6.3％) by CT and 2 segments (12.5％) by MRI showing typical Tram track sign.The relationship between ossified mass and dura mater was that 7 segments (43.8％) by CT and 7 segments (43.8％) by MRI with "C" sign and 7 segments (43.8％) by CT and 8 segments (50.0％) by MRI with "V" sign.The ossified mass OR was 60.5％± 13.0％ in the group with DO and 42.2％± 12.3％ in the group without DO.There was a significant difference between the two groups (t=5.192,P＜0.001).Among the 16 segments with DO,the ossified mass OR of 7 segments with "C" sign was 68.8％± 12.8％ and that of the other 9 segments without "C" sign was 54.39％±9.9％.There was significant difference between the two groups (t=2.45,P=-0.028).Histological examination showed that there were two pathological phenomena in the dura tissue adjacent to ossified mass.The one,there were fibrocartilage,cartilage and osteogenesis in the dura mater.The other,the unossified dura mater fused with the ossified mass but with clear histological demarcation,while the dura mater on the ventral side of the ossified ligamentum flavum atrophies or disappeared.Conclusion The occurrence of dural sac ossification is associated with the ossification of ligamentum flavum beginning at the side of the dural sac and the persistent thickening of the ossified mass.The pathological manifestations of DO are ossification of dural tissue or fusion of dural with ligamentum flavum ossification.%目的 探讨胸椎黄韧带骨化合并硬膜囊骨化的影像学特征及其病理学表现.方法 回顾性分析采用胸椎椎板-黄韧带骨化物整块切除术治疗的胸椎黄韧带骨化症患者29例(62个节段),男19例,女10例;年龄(54.9±10.25)岁(范围36～77岁).其中合并硬膜囊骨化11例16个节段,无合并硬膜囊骨化18例46个节段.观察CT骨窗和MRt横断面T2WI的骨化物形状和骨化物与硬脊膜的关系,测量CT骨窗横断面单侧椎管占有率.取2例合并硬膜囊骨化患者术中病理标本行HE染色检查.结果 骨化物形状:合并硬膜囊骨化的16个节段中,CT有7个节段(43.8％)、MRI有2个节段(12.5％)表现为黄韧带硬膜囊侧存在骨化层;CT有1个节段(6.3％)、MRI有2个节段(12.5％)表现为典型的Tram track征.骨化物与硬脊膜的关系:CT有7个节段(43.8％)、MRI有7个节段(43.8％)表现为“C”形征;CT有7个节段(43.8％)、MRI有8个节段(50.0％)表现为“V”形征.合并硬膜囊骨化组单侧骨化物椎管占有率为60.5％±13.0％,无合并硬膜囊骨化组为42.2％±12.3％,两组差异有统计学意义(t=5.192,P＜0.001).合并硬膜囊骨化的16个节段中,有“C”形征表现的7个节段的单侧骨化物椎管占有率为68.8％±12.8％,无“C”形征出现的9个节段的单侧骨化物椎管占有率为54.39％±9.9％,两组差异有统计学意义(t=2.45,P=0.028).组织学检查可见硬脊膜与骨化物的交界存在两种病理现象:硬脊膜内存在纤维软骨、软骨和成骨的移行区;未骨化硬脊膜与骨化物融合,组织学分界清晰,黄韧带骨化物腹侧硬脊膜萎缩或消失.结论 硬膜囊骨化的发生与黄韧带骨化始于硬膜囊侧和骨化物持续增厚相关,硬膜囊骨化的病理学表现是局部硬脊膜组织骨化或硬脊膜与黄韧带骨化物组织融合.