髂腰肌囊扩张的影像诊断与鉴别诊断

目的探讨髂腰肌囊扩张的CT、MRI表现，明确其诊断与鉴别诊断。方法回顾性分析经手术、穿刺或随访证实的16例髂腰肌囊扩张病人的临床及CT、MRI资料。结果16例(17髋)病变为薄壁单房(14例)或多房状(2例)囊性肿物，位于部分或全部髋臼层面，髋关节囊前方，髂外或股动静脉后外方，其中5例沿髋臼或髂骨基底内侧面向上延伸，并突入髂腰肌内，9例(10髋)向下延伸，位于耻骨肌前外侧，止于股骨小转子水平或其以上。上下范围为1.2-7.8cm，最大显示层面面积(横径×纵径)为0.6cm×1.9cm-2.7cm×4.5cm。CT平扫(5例)腔内为低密度，CT值8-35HU，平均16HU。9例行MR扫描，其中7例T1WI呈低信号，T2WI呈高信号，T2STIR呈高信号，2例(血性、脓性积液者各1例)T1WI呈等或高信号，T2WI和STIR呈不均匀高信号。2例CT增强检查，囊壁呈轻-中度强化。10例显示扩张的髂腰肌囊与髋关节直接相通，7例可见其在关节囊的开口。结论 CT和MRI对髂腰肌囊扩张的诊断及鉴别诊断有重要价值。

Imaging diagnosis and differential diagnosis of enlarged iliopsoas bursa

Objective To explore CT and MRI features of enlarged iliopsoas bursa, To clarify its diagnosis and differential diagnosis. Methods CT/MRI and clinical data of 16 patients with enlarged iliopsoas bursa confirmed by following up, aspiration of synovial fluid or surgical operation were studied retrospectively. Results The lesions in all 16 cases（17 hips） were presented as unilocular（n=14） or multiloculated（n=2） cysts with thin wall, appeared at the level of or part of the acetabulum sections, located in front of the hip joint capsules, posterolateral to the external iliac or femoral blood vessels, 5 bursas extended upwards along the acetabulum and internal surface of the ilium base, protruding into iliopsoas muscle, 9 cases（10 bursas） went downwards and located anterolaterally to pectineal muscle. The biggest diameter of lesions ranged from 1.2-7.8cm, the area（transverse diameter~ vertical diameter） at the largest section was from 0.6cm x 1.9cm-2.Tcm ~ 4.5cm. On CT films 5 cases showed hypodense lesions with CT value from 8-35Hu, the average value was 16HU. In 9 cases examined by MRI, 7 bursas appeared low signal on TlWI, high signal on T2WI, and marked high signal on STIR, 2 bursas（1 case with hematocele, 1 case with empyema） appeared as equal or high signal on TlWI and inhomogeneous high signal on T2WI and STIR. In 2 cases with contrast enhanced CT, mild to moderate enhancement of the cystic wall could be seen. 10 cysts communicated with joint cavity, 7 cysts opened auterior to hip joint capsule. Conclusion CT and MRI play important value in diagnosing and identifying the enlarged iliopsoas bursa.