股骨颈疝窝的影像学表现及诊断误区

目的研究股骨颈疝窝X线、CT及MRI影像表现与诊断误区。方法 5例由临床或手术证实为股骨颈疝窝患者均经CT扫描,3例又经X线平片检查,4例又经MRI检查。对所有患者的影像资料进行了回顾性分析。结果 5例股骨颈疝患者中,CT误诊为骨腱鞘囊肿2例,X线平片误诊为缺血性骨坏死和骨样骨瘤各1例,MRI与CT、X线平片共同正确诊断股骨颈疝窝1例。5例疝窝均位于股骨颈前外侧1/4处,疝窝大小为0.6cm×0.8cm～1.4cm×2.0cm。X线平片示股骨颈区囊状低密度区,边缘清楚且围以硬化边。CT示股骨颈皮质下低密度区,有硬化边缘,其中2例伴发骨皮质细微断裂。4例经MRI检查的患者,其病变在T1WI呈低信号,在T2WI呈高信号,在脂肪抑制T2WI呈更高信号,其中2例病灶边缘围以低信号带。T2WI显示髋关节少量渗液2例。结论股骨颈疝窝具有特征性CT、MRI表现,X线平片、CT、MRI相互结合有助于股骨颈疝窝的确诊。

Imaging findings and diagnostic pitfalls of herniation pits of the femoral neck

Objective To study the imaging findings and diagnostic pitfalls of herniation pits of the femoral necks（HPFN）.Methods Five patients with clinically or surgically proved HPFN underwent CT scans,of whom,3 cases underwent additional plain radiographies and 4 cases underwent additional MRI examinations.The imaging data of all patients were analyzed retrospectively.Results Among 5 patients with HPFN,CT scans misdiagnosed as bony ganglia in 2 cases,plain radiographies misdiagnosed as ischemic osteonecrosis and osteoid osteoma in 1 case each,and MRI,CT and plain radiography together correctly diagnosed HPFN in 1 case.The herniation pits of 5 cases were all located in the anterior-lateral quadrant of the femoral necks.The diameter of HPFN lesions ranged from 0.6 cm to 2.0 cm.Plain radiography showed cystoid hypodense areas with well-defined sclerotic margin in the femoral neck.CT scans showed subcortical hypodense areas with sclerotic margin,of whom,2 cases associated with fine rupture of the bone cortex.Four patients who underwent MR imaging,whose HPFN lesions were hypointensity on T1WI,hyperintensity on T2WI,and higher signal intensity on SPIR T2WI.Two cases were found to be the lesion periphery surrounded by hypointense band.T2WI showed there was a little exudation in the hip joints of 2 cases.Conclusion HPFN lesions have specific findings on CT and MRI,while the combination of plain radiography,CT and MRI is helpful for definitely diagnosing HPFN.