目的：探究计算机辅助诊断（computer-aided diagnosis,CAD）系统辅助超声医师诊断甲状腺弥漫性病变合并结节良恶性的效能。方法：收集2017年8月至2017年12月在我院就诊并行超声检查的甲状腺弥漫性病变合并结节患者342例（共533个结节）,以病理检查结果为金标准,比较按常规超声诊断方法（依据成人甲状腺结节与分化型甲状腺癌指南的标准）与CAD系统辅助下超声诊断判断甲状腺弥漫性病变合并结节良恶性的灵敏度、特异度、阳性预测值、阴性预测值及受试者操作特征曲线（receiver operator characteristic curve, ROC曲线）的曲线下面积（erea under the curve, AUC）。结果：常规超声诊断甲状腺弥漫性病变合并结节良恶性的灵敏度为96.6%,特异度为72.5%,AUC为0.846;在CAD系统辅助下超声诊断的灵敏度为96.6%,特异度为80.9%,AUC为0.888。在CAD系统辅助下的诊断特异度和AUC均较高（P均<0.01）。结论：对于甲状腺弥漫性病变合并结节的患者,采用超声联合CAD系统诊断甲状腺结节良恶性时,可在保持灵敏度不变的同时提升诊断特异度,以减少不必要的穿刺活检。

Objective: To investigate the effect of ultrasound by computer aided diagnosis (CAD) system in diagno-sing nodules in patients with diffuse thyroid lesions. Methods: A total of 342 patients with diffuse thyroid lesions and thyroid nodules who underwent thyroid surgery in our hospital during August 2017 to December 2017 were enrolled. Based on guidelines for adult thyroid nodules and differentiated thyroid cancer, ultrasound with and without CAD were performed on 533 nodules from the patients. The findings of ultrasound were compared with pathological results, and sensitivity, specificity, positive predictive value, negative predictive value, and area under the ROC curve(AUC) were calculated to observe difference in efficacy between ultrasound and ultrasound by CAD system. Results: The sensitivity, specificity of conventional ultrasound for diagnosing malignant and benign nodules in diffuse thyroid lesions was 96.6%, 72.5%, with AUC of 0.846. While the diagnostic sensitivity, specificity of ultrasound and ultrasound by CAD system was 96.6%, 80.9%, with AUC of 0.888. The use of CAD system enabled ultrasound achieve a higher specificity and AUC (P<0.01). Conclusions: For patients with diffuse thyroid lesions, ultrasound aided by CAD has a better specificity in diagnosis of thyroid nodules, which may reduce unnecessary puncture biopsies.