MRI SEMAC序列在人工全髋关节置换术后评估中的应用

Application of MRI SEMAC sequence in post-operative evaluation of total hip arthroplasty

目的 探讨1.5T MRI去金属伪影技术SEMAC序列在人工全髋关节置换术后评估中的应用价值。方法 选取21例人工全髋关节置换术后患者的MRI图像,比较患者髋关节MRI常规序列和SEMAC序列扫描的假体信号丢失的程度以及其周围软组织结构的显示范围,评价其图像质量,分析MRI显示骨质结构及周围软组织变化的情况。结果 SEMAC序列中髋臼假体结构扭曲、边缘模糊效应明显低于常规序列,SEMAC序列信号丢失面积,T_(2)WI (21.29±2.19) cm^(2),T_(1)WI (19.12±2.73) cm^(2),明显小于常规序列信号丢失面积,T2WI (41.32±2.60) cm^(2)和T_(1)WI (41.43±1.85) cm^(2);SEMAC序列图像质量评分为(4.47±0.98)分,明显高于常规序列的图像质量评分(3.09±0.83)分,差异具有统计学意义(P<0.05)。SEMAC序列可清楚的显示关节积液、骨溶解、关节囊内炎性假瘤、肌肉肌腱损伤等假体周围骨质及软组织异常改变。结论 1.5T MRI SEMAC序列可以很好地降低假体的磁敏感伪影,能够更加清晰的显示假体周围骨质及软组织结构的异常改变,为临床人工全髋关节置换术后患者疼痛原因的评估提供一种更加行之有效的检查方法。

Objective To evaluate the application value of 1.5T MRI metal artifact removal SEMAC sequence in post-operative evaluation of total hip arthroplasty. Methods We collected a total of 21 cases of patients after total hip arthroplasty MRI image, compared with conventional scanning sequence and SEMAC sequence MRI in patients with hip prosthesis signal loss degree and its surrounding soft tissue structure of the display area, evaluated its image quality, and analysed the MRI images displayed on the structure change of bone and surrounding soft tissue. Results The structural distortion and edge ambiguity of the acetabular prosthesis in the SEMAC sequence were significantly lower than those in the conventional sequence. The signal loss area of the SEMAC sequence [(21.29±2.19) cm^(2) on T_(2)WI,(19.12±2.73) cm^(2) on T_(1)WI] was significantly smaller than that of the conventional sequence [(41.32±2.60) cm2on T_(2)WI and(41.43±1.85) cm2on T1WI]. The image quality score of SEMAC sequence was(4.47±0.98), which was significantly higher than that of conventional sequence(3.09±0.83), and the difference was statistically significant(P<0.05). The SEMAC sequence can clearly show the abnormal changes of bone and soft tissue around the prosthesis, such as joint effusion, osteolysis, inflammatory pseudotumor in the joint capsule, muscle tendon injury and so on. Conclusion 1.5T MRI SMAC sequence can well reduce the magnetic sensitive artifacts of prosthesis, and can more clearly display the abnormal changes of bone and soft tissue structure around the prosthesis, which provides a more effective examination method for the evaluation of pain causes in patients after total hip arthroplasty.