隐性骨折的MRI分析

目的 探讨隐性骨折的MRI诊断价值。方法 16例急性外伤患者均行X线平片检查及MRI检查，3例同时行CT检查，受伤部位分别为股骨髁3例，胫骨近端8例，胸腰段椎体5例。结果 本组16例X线平片均未见骨折征像；11例（11／16）股骨髁及胫骨近端受伤病例中3例（3／16）T1WI见骨皮质下线状信信号带改变，8例（8／16）显示由关节面下向骨干走行的不规则条状、紊乱低信号改变；在T2WI上对应于T1WI低信号区仍表现为相应形状的低信号，且在低信号周围可见高信号水肿改变；T1脂肪抑制序列扫描显示水肿带信号明显增强、增宽。2例股骨髁和1例胫骨近端病例同时行CT检查，示周围软组织肿胀，未见确切骨折征像。5例（5／16）胸腰段椎体MR T1WI、T2WI示椎体中央有水平方向走行的线状低信号带，在T2WI低信号周围可见高信号水肿。结论 MRI能够早期确诊隐性骨折，若患者临床症状、体征不能除外隐性骨折，X线检查后行MRI应为最佳的检查手段。

MR imaging of occult fractures

Objective To investigate the value of MR imaging in detecting occult fractures. Methods Sixteen cases with acute trauma were studied using radiography and MR imaging, three cases also underwent CT examinations. Three fractures occurred in the femur condyle, 8 in the proximal tibia and 5 in the thoracolumbar spine. Results All sixteen cases had normal radiographic results. In 11 cases with femur condyle and tibia occult fracture, MR imaging demonstrated linear low signal in the subcortical region in 3 cases and irregular low signal from articular faces to shaft in 8 cases on both T 1WI and T 2WI, and high signal changes around low signal were seen on T 2WI, and the width of low signal was less than 4 mm on both T 1WI and T 2WI. The high signal in T 1 weighted-Fat saturated sequence was more remarkable and wider than that on T 2WI. 3 cases with CT scanning showed no fracture signs. In five cases with thoracolumbar vertebral occlut fractures, MR imaging demonstrated horizontal linear low signal in the center of vertebra on both T 1WI and T 2WI, and high signal changes around low signal were seen on T 2WI. Conclusions MR imaging could early determine the diagnosis of occult fractures. MRI should be the next examination of choice when plain films fail to reveal suspected fractures in the setting of suggestive symptoms and positive physical examination.