高分辨率CT骨密度测量诊断前庭窗型耳硬化症

目的 探讨应用高分辨率CT(HRCT)骨密度测量法诊断耳硬化症的应用价值。方法 回顾性分析经手术证实的30例耳硬化症患者(耳硬化组)和32名正常对照者(对照组), 将ROI置于前庭窗前区进行骨密度CT值测量, 并对耳硬化患者进行语频气导和气骨导差听力测试。采用两样本t检验对硬化耳和正常耳骨密度平均CT值进行统计学分析、采用Pearson相关系数分析对耳硬化组平均CT值和听力水平进行分析, 并采用ROC曲线分析检测应用CT值诊断耳硬化症的效能。结果 硬化组前庭前区CT值范围462.81-2285.00 HU, 平均(1372.82±76.50)HU, 对照组前庭前区CT值范围1801.71~2680.55 HU, 平均(2171.42±23.53)HU, 耳硬化组平均CT值明显低于正常组(P <0.0001);硬化耳平均CT值与语频气导阈值(r=0.18, P=0.19)、与气骨导差(r=-0.01, P=0.93)均无明显相关性。采用平均CT值鉴别耳硬化症的ROC曲线下面积为0.88(P <0.05), 诊断阈值为1938.29 HU, 诊断的敏感度为80.7%, 特异度为90.6%。结论 骨密度测量对于诊断耳硬化症具有重要应用价值, 但其对听力评估的应用有待进一步研究。

Measurements of bone density on high resolution CT in diagnosis of fenestral otosclerosis

Objective To explore the value of bone density measure in the diagnosis of fenestral otosclerosis by high resolution CT (HRCT). Methods Totally 30 patients with otosclerosis (otosclerosis group) proved by operation and 32 normal controls (control group) were analyzed retrospectively. A ROI was placed in the bony labyrinth located anterior to oval window to measure the bone density, and the average for the speech frequency air conduction threshold levels and air-bone gap in otosclerosis group were measured. The mean CT value were compared between otosclerosis group and control group using two-sample t-test, and the correlation between mean CT value and hearing levels were analyzed by pearson correlation coefficient analysis. In addition, the efficiency of mean CT value in diagnosis of otosclerosis were analyzed by calculating the area under the ROC curves (AUC). Results The mean CT value was significantly lower in otosclerosis group (rang 462.81-2285.00 HU, mean HU) than that in control group (range 1801.71-2680.55 HU, mean HU, P <0.0001), and there was no significant correlation between CT value and the speech frequency air conduction threshold levels (r=0.18, P=0.19) and air-bone gap (r=-0.01, P=0.93, respectively) in otosclerosis group. Taking 1938.29 HU as the cut-off value, the AUC for the diagnosis of otosclerosis was 0.88 (P <0.05), and the sensitivity was 80.7%, the specificity was 90.6%. Conclusion The bone density measure has important value in diagnosis of otosclerosis, but its application in hearing assessment remains to be further studied.