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目的：探讨三维自适应迭代剂量降低（AIDR 3D）联合自动曝光控制技术在头颅CT检查中的应用效果。方法将80例患者随机均分为两组：A组采用常规剂量扫描（管电压120 kV ，管电流350 mA ，采用滤波反投影算法重建）；B组采用自动曝光控制技术（SD＝6.5，管电压120 kV ，管电流40～400 mA ，采用AIDR 3D迭代算法重建）。比较两组的图像噪声、信噪比（SNR）、对比噪声比（CNR）、CT剂量指数（CTDI）和剂量长度乘积（DLP）。结果 A 组的图像噪声、CTDI及DLP均高于B组，SNR和CNR均低于B组（P＜0．01）。两组图像质量评分比较差异无统计学意义（Z＝－1.897，P＞0．05）。结论在头颅CT检查中，相较于滤波反投影重建，AIDR 3D联合自动曝光控制技术在不降低图像质量的前提下可有效降低辐射剂量。“,”Objective To study the outcomes of adaptive iterative dose reduction 3D(AIDR 3D) combined with automatic exposure control technology in head CT scan .Methods Eighty patients were equally and randomly divided into two groups .The head CT scan in group A was performed with conventional dose scan[tube voltage 120 kV ,current 120 mA ,filtered back projection(FBP) algorithm reconstruction] and that in group B with automatic exposure control technique (SD =6.5 ,tube voltage 120 kV ,current 40‐400 mA ,AIDR 3D reconstruction ) .The image noise and ratio of signal to noise (SNR) ,ratio of contrast to noise(CNR) ,CT dose index(CTDI) and dose length product(DLP) were compared between two groups .Results The image noise ,CTDI and DLP of group A were higher than those of group B ,the SNR and CNR of group A were lower than those of group B(P0 .05) .Conclusion In head CT scan ,compared with FBP reconstruction ,AIDR 3D combined with automatic exposure control technology can reduce the radiation dose without reducing image quality .