股骨头缺血坏死并髂腰肌囊扩张的影像学表现

Imaging Manifestations of Enlarged Iliopsoas Bursa in Ischemic Necrosis of Femoral Head

目的 探讨髂腰肌囊扩张的CT、MRI表现 ,明确其诊断、原因及意义。资料与方法 回顾性分析具有典型影像学表现和 /或经病理或随访证实的 86例 (138髋 )成人股骨头缺血坏死患者的CT和MRI片 ,从中挑选出伴髂腰肌囊扩张者 17例 (18髋 )进行分析。结果 18髋均为圆形、卵圆形或倒水滴状囊性肿物 ,位于髋关节囊前方 ,髂外或股动静脉后外方和髂腰肌 (腱 )内侧。MR上T1WI呈低信号 ,T2 WI呈高信号 ,T2 WI +脂肪抑制呈明显高信号。CT上为等或略低密度 ,CT值 12～ 4 5HU。 5例增强检查 ,囊壁轻度强化。Ⅱ级关节积液并髂腰肌囊扩张 12髋 ,Ⅲ级关节积液并髂腰肌囊扩张 6髋。Ⅱ级关节积液并髂腰肌囊扩张多于Ⅲ级关节积液 (P <0 .0 0 1)。结论 股骨头坏死并髂腰肌囊扩张见于股骨头缺血坏死中晚期 。

Objective To discuss CT and MRI features of enlarged iliopsoas bursa in ischemic necrosis of femoral head, to clarify its pathogenesis and clinical significance.Materials and Methods From 86 cases (138 hip joints) with typical imaging signs of, or pathologically-proved, ischemic necrosis of femoral head, 17 cases (18 hip joints) who showed enlarged iliopsoas bursa on CT or MRI were selected. Imaging findings were analyzed.Results The enlarged iliopsoas bursa in all 18 hips was presented as round, oval or inverted water-drop cystic shadow, locating in front of the hip joint capsule, posterolateral to the external iliac or femoral blood vessels and medial to iliopsoas muscle. It displayed low signal on T 1WI, high signal on T 2WI, and markedly higher signal on STIR. On CT scans, it was presented as iso- or slightly hypo-density, with a CT value of 12～45 HU. On enhanced scans (n=5), slight enhancement of the cystic wall could be seen. Ⅱ and Ⅲ degree hydrarthrosis was found in 12 and 6 hips, respectively. Enlarged iliopsoas bursa occurred more frequently in the patients with Ⅱ degree hydrarthrosis than in the patients with Ⅲ degree hydrarthrosis (P<0.001). Conclusion Enlarged iliopsoas bursa occurs in the middle or late stage of ischemic necrosis of femoral head, indicating that further medical management is needed.