临界性大前庭导水管的HRCT表现

HRCT appearances of the bordline large vestibular aqueduct

目的总结临界性大前庭导水管的HRCT表现,提高对LVA的认识,减少CT漏诊率。方法回顾性分析经MRI确诊的73例（143耳）LVA HRCT资料,其中13例（15耳）为临界性LVA,分析其HR CT表现,并与其MRI对照。在Carestream10.2PACS系统上行前庭导水管标准轴位、矢状位重建,测量前庭导水管中间径大小。结果临界性大前庭导水管占同期LVA的10.5%（15/143）,其中双侧2例、单侧11例。在前庭导水管HRCT轴位图像、矢状位图像上其后肢中段宽度位于0.95～1.30mm（均值1.21mm）,0.97～1.29mm（1.19mm）,其近段与前庭相通。在MRI积极干预稳态序列（CISS）序列上前庭导水管及骨内外内淋巴囊均有不同程度扩张,以骨外明显。其中1耳内淋巴囊内呈均匀高信号,其余14耳内淋巴囊内信号不均匀,其中3耳合并耳蜗Mondini及前庭扩大畸形。结论临界性大前庭导水管并非少见,HRCT上表现为前庭导水管轻度扩张。MRI检查可弥补HRCT的不足,有助于减少漏诊率。

Objective To summarize the HRCT appearances of the bordline large vestibular aqueduct,and to improve the knowledge of the disease and reduce missing.Methods 13cases（15ears）of the large vestibular aqueduct were found in 73patients（143ears）conformed by clinical documents and MRI,their relevant HRCT documents were studied retrospectively.Standard axial and sagittal MPR images were done on Carestream10.2PACS.Results The morbidity is about10.5%（15/143）.11 are unilateral,two cases are bilateral.The mid values of the vestibular aqueduct back limb are 0.95～1.30mm（average：1.21mm）,0.97～1.29mm（average：1.19mm）.The vestibular aqueduct and endolymphatic sac were slightly dilated.The dilated vestibular aqueduct could also be identifed when it came into vestibule whether intraossous or extraossous.on CISS Sequence of MRI,one ear appeared high signal,the others represented mixed signal in the all the enlarged endolymphatic sacs.Conclusion The bordline large vestibular aqueduct is not rare.On HRCT,the vestibular aqueduct is slightly dilated.MRI could retrieve insufficience of CT,and could reduce missing diagnosis.