中颅窝盖板低位的高分辨率CT“分度标准”构想  

Clinical significance of grading low middle fossa tegmen plate with high-resolution computed tomography

作　　者：孙晓卫[1] 李东梅[1] 窦芬芬[1] 张子和[1] 张建基[1] 丁元萍[2] 史丽[2] 

机构地区：[1]济南市儿童医院耳鼻喉科,山东济南250022 [2]山东大学齐鲁医院耳鼻咽喉头颈外科,山东济南250012

出　　处：《山东大学耳鼻喉眼学报》2015年第6期22-25,共4页Journal of Otolaryngology and Ophthalmology of Shandong University

摘　　要：目的观察中颅窝盖板低位对耳后进路清除上鼓室病变的影响,探讨中颅窝盖板低位的分度标准。方法对87例影像科报告中颅窝盖板低位的慢性化脓性中耳炎患者的CT图像进行冠状位重建,沿外耳道上壁最高点作水平切线L1,自该层面出现上半规管结构的最高点作水平切线L2,沿该层面的中颅窝盖板最低点作水平切线L3,测量L1~L2距离a和L1~L3距离b,计算b/a值r,依据r值将中颅窝盖板低位分为正常、轻、中、重及绝对低位,与3位手术医生术前评估及手术记录结果进行比较。结果手术医生根据不同的r值,不同观点如下：1当r〈1/4时,不认同影像科提示的中颅窝盖板低位;2当1/4≤r〈1/3时,认同中颅窝盖板低位,但手术记录中未提及;3当1/33/4时,清除上鼓室病变时非常困难,中颅窝盖板低位导致的耳后进路已不可避免的要磨除外耳道后壁。结论可依据r值可将中颅窝盖板低位分无、轻、中、重及绝对低位＂5度＂,轻度对耳后进路清除上鼓室病变无影响,中度耳后进路清除上鼓室病变存在困难,重度经耳后进路清除上鼓室病变部分需要磨除外耳道后壁,绝对低位时磨除外耳道后壁已不可避免。Objective To observe the effect of high-resolution computed tomography （HRCT）grading of low middle fossa tegmen plate on the elimination of diseased tissue in epitympanum and to investigate the grading standard of low middle fossa tegmen plate.Methods The CT images obtained from 87 chronic otitis media （COM）cases were sub-jected to coronal reconstruction.A horizontal tangent L1 at the highest point along the upper wall of external auditory canal,a horizontal tangent L2 at the highest point of the semicircular canal structure,and a horizontal tangent L3 at the lowest point along the middle fossa tegmen plate were created to measure the distance between L1 and L2,L1 and L3, and to calculate the r value （b/a）.The r value was used to divide the low middle fossa tegmen plate into five grades：non-low,mild,moderate,severe,and absolute low.Pre-operative evaluation and postoperative results were compared. Results Surgeons had different opinions on the r value：（1）If r 〈1 /4,the low middle cranial fossa cover identified by the Radiation Department could not be accepted.（2）If 1 /4 ≤ r 〈1 /3,the low middle cranial fossa cover identi-fied by the Radiation Department could be accepted,but it was not mentioned in the operation record.（2）If 1 /3 〈r ≤ 1 /2,wearing was found at the bottom wall of the middle fossa tegmen plate upon clearing the diseased tissue,and the operation would be affected because of bleeding.（4）If 1 /2 〈r ≤3 /4,the surgeons were able to identify the low middle fossa tegmen plate before operation;but some cases’back wall of the external auditory canals could be preserved after the diseased tissue in the epitympanum was cleared.（5）If r 〉3 /4,the surgeons experienced difficulty in finding the trum tympanicum and pathway behind the ear because the low middle fossa tegmen plate wore down the back wall of external auditory canal.Conclusion The r value can be used to divide the low middle fossa tegmen plate into five grades：non,mild,moderate,severe,and absolute

关 键 词：中颅窝 鼓室病变 颅底 颞骨 体层摄影术 X线计算机 

分 类 号：R764.4[医药卫生—耳鼻咽喉科]