MRI水样信号在椎体压缩骨折中的诊断价值

Diagnostic value of fluid sign at MRI in vertebral compression fracture

目的根据MRI水样信号特征,鉴别椎体压缩骨折的原因。方法比较142例MRI上有椎体压缩骨折的病例,其中有明确原发恶性肿瘤病史的椎体转移性肿瘤65例(197个椎体),外伤77例(96个椎体),外伤时间12 h^20年。采用GE Signa1.5T超导磁共振成像仪,常规作矢状位T1加权成像(T1WI)、T2加权成像(T2WI)和脂肪抑制T2加权(STIR)成像、横断位STIR成像,转移瘤患者中有29例作Gd-DTPA静脉增强后矢状位、冠状位和横断位脂肪抑制T1WI;外伤病例中仅1例作增强扫描,其中15例又作了CT平扫。结果在压缩骨折的椎体中水样信号以椎管内的脑脊液为参照,其形态为线形、三角形和斑片状,在55例急性、亚急性和慢性早期(≤3月)患者的68个椎体外伤中,25例患者的31个椎体(31/68,45.2%)出现水样信号;在65例转移性肿瘤所致的椎体骨折中,12例患者的26个椎体(26/197,13.2%)出现水样信号;在22例慢性中后期(>3月)患者的椎体外伤中,2例患者的3个椎体(3/26,11.5%)出现水样信号。结论MRI水样信号在急性、亚急性和慢性早期的外伤性椎体压缩骨折中出现,提示骨髓水肿;在转移性肿瘤所致的椎体压缩骨折中水样信号很少出现,对于鉴别良恶性椎体骨折有一定的参考价值。

Objective To investigate the cause of vertebral compression fracture according to the characteristics of fluid sign at MRI. Methods One hundred and forty-two patients with vertebral compression fractures due to metastatic infiltration （65 cases, 197 vertebrae） or trauma （77 cases, 96 vertebrae） were studied. The duration of trauma varied from 12 hours to 20 years. The regular MRI examination included sagittal T1WI, T2WI, STIR and axtial STIR imaging. Twentynine cases with metastatic tumor were examined with Gd-DTPA. Only one of the patients of trauma was performed enhanced scanning, and 15 were also performed CT examination. Results In fracture vertebral bodies, fluid sign was adjacent to the fractured end plates and exhibited signal intensity isointense to that of cerebrospinal fluid. Fluid sign was linear, triangular or focal, and was found in 25 （31 vertebrae） of the 55 patients （68 vertebrae） with acute, subacute, and early chronic trauma fracture（ ≤ 3 months, 31/68, 45.2% ）. Fluid sign occurred in 12 cases （26 vertebrae） of neoplastic vertebral compression （26/197, 13.2% ）. And in the 22 cases （26 vertebrae） of chronic trauma （ 〉3 month）, fluid sign was observed in 2 （3 vertebrae, 3/26, 11.5% ）. Conclusion Fluid sign is characteristic in acute, subacute and early chronic trauma vertebral compression fracture for bone marrow edema, while it is rare in metastatic tumor vertebral compression fracture. It may paly a role in the differentiation of benign and malignant vertebral compression fracture.