大前庭导水管综合征螺旋CT扫描测量与听力的关系分析

目的：评估前庭导水管扩大和听力损失的关系，并获得颞骨冠状位螺旋CT（SCT）扫描测量诊断前庭导水管扩大（LVA）的限值。方法：回顾性研究郑州大学第三附属医院LVA患者的颞骨SCT扫描资料，在横断位和冠状位上测量LVA患者和正常人的前庭导水管中点直径和外口宽度。两次的听力测试用以评估LVA患者听力演变。结果：LVA患者前庭导水管横断位平均中点直径为（2.4±0.93） mm，平均外口宽度为（6.21±1.4） mm，冠状位平均中点直径为（5.48±1.76） mm，平均外口宽度为（6.87±1.61） mm。冠状位诊断导水管扩大限值，中点直径为2.5 mm或外口宽度为4.25 mm。患者空气传导和骨传导两次听力阈值差异不显著，P＞0.05。随访显示64.3％的患者听力损失维持在轻度和中度水平，仅有2例患者听力改善，5例听力下降。骨传导阈值和前庭导水管的直径之间无相关性，空气传导低频时听力阈值和前庭导水管直径相关性强。结论：空气传导听力损耗是LVA患者传导性或混合性听力损失的主要因素。冠状位SCT扫描可以提供额外的信息来评估LVA，尤其是在横断位扫描诊断依据不足时。

Analysis of the relationship between large vestibular aqueduct syndrome and hearing by SCT

Objective： To evaluate the relationship between large vestibular aqueduct （LVA） and heating loss, also obtain the threshold of LVA on coronal SCT of temporal bone. Methods： The SCT features of temporal bone from patients with enlarged vestibular aqueduct in the third affiliated hospital of Zhengzhou university were studied retrospectively. The midpoint diameter and width at the outlet of vestibular aqueduct were measured both on the axial and coronal SCT in normal individuals as well as in patients. The heating tests from two different times were also performed to assess the evalution of heating loss in patients with LVA. Results： In patients, the average midpoint diameter of the aqueduct was （2.4±0.93） mm and the average width of the aqueduct outlet was （6.21±1.4）mm on transverse view, the midpoint average diameter was （5.48±1.76）mm and the average width of the outlet was （6.87±1.61）mm on coronal view. The threshold value of the transverse diameter of the aqueduct for diagnosis of LVA was 2.5 mm, and the width of the outlet of the aqueduct was 4.25 mm on coronal view. There were no significant differences of both the air conduction and bone conduction from the two different times in patients, P〉 0.05. Follow-up study showed that 64.3% patients had mild to moderate hearing loss, only 2 cases had hearing improvement, 5 cases had hearing loss. There was no correlation of the vestibular aqueduct diameter with the bone conduction threshold value, while there was strong correlation between air conduction threshold and vestibular aqueduct diameter at low frequencies. Conclusion： Air conduction is the main factor in LVA patients with conductive or mixed heating loss. SCT coronal scans can provide additional information to assess the LVA, especially when the axial scan diagnosis is insufficient.