臀肌挛缩症的影像学回顾性分析

Retrospective Analysis on Imaging Diagnosis of Gluteus Muscle Contracture

目的分析影像学检查在臀肌挛缩症(gluteus muscle contracture,GMC)中的应用及与临床手术对照。方法经临床诊断及外科手术证实GMC共18例。术前常规行X线及MR检查,X线为骨盆正位,MR检查包括轴位T1WI,T2WI及T2WI FS与冠状位T2WI。2名患者术前行CT检查。结果全部18例患者,X线检查全部可见骨盆倾斜,15例见骶髂关节旁致密线影,3例臀肌旁卵圆形高密度影;2例CT主要表现臀肌形态萎缩变小;MR检查15例双侧臀肌变薄,3例单侧臀肌变薄,肌间隙增宽并见脂肪信号影增多,15例患者共27侧臀中肌纤维条索样改变,18例患者共33侧臀大肌外侧缘自髂骨翼至股骨大形态萎缩变小粗隆行程可见增厚纤维条索影,冠状位可显示纤维条索行程。所有病例均经手术证实为臀肌挛缩症,并与影像学检查相符;臀大肌、臀中肌及臀小肌病变诊断率分别为100%,93.8%及94.7%,但臀小肌病变诊断假阴性率为21.7%。结论 X线及CT髂骨致密线影对GMC诊断有重要提示意义,MR能直接显示受累萎缩的臀肌及增厚纤维条索影,对外科手术治疗有重要指导意义。

Objective To analyze the imaging findings of gluteus muscle contracture （GMC）, and to compare imaging findings with operative findings.Methods 18 cases with clinically and surgically confirmed GMC were performed with X-ray （pelvic Ap X-ray plain film） and MRI scanning （axial-T1WI, T2WI, T2WI Fatsat and Cor-T2WI）,in which 2 patients underwent CT scanning.Results Pelvic obliquity could be observed in all the 18 patients; longitudinal dense liniar shadows could be seen in 15 patients; oval shaped well-defined high density shadows could be seen in 3 patients by X-ray. Gluteus muscles atrophy were shown in 2 patients by CT scanning. MR images showed bilateral thinning gluteus muscle in 15 patients and lateral thinning gluteus muscle, intermuscular space broadening and increased fat signal in 3 patients. Gluteus medius fibrous bands could be observed in 15 patients （27 laterals）. 18 patients （33 laterals） with fibrous band of gluteus maximus muscle were observed in Cor-T2WI. All 18 cases were affirmed by operation and matched with imaging findings. Diagnostic rate of gluteus maximus, gluteus medius and gluteus minimus was 100%, 93.8% and 94.7%, but the false negative rate of gluteus minimus was 21.7%.Conclusion Longitudinal dense liniar shadows were important suggestion in X-ray and CT for the diagnosis of GMC. MR could show the gluteus muscles atrophy and the thickening fibrous bands, which have guiding significance in GMC operation.