目的 提供一个规范化的肺癌筛查胸部低剂量CT（low-dose computed tomography，LDCT）检查方案，合理、规范地应用胸部LDCT检查技术，为胸部LDCT应用于肺结节的检出和诊断提供指导。 方法 由中华医学会影像技术分会专家团队共同参与了肺癌筛查胸部LDCT检查技术规范的制定工作。根据近年来国内外LDCT肺癌筛查进展，结合我国肺癌流行病学特征，在检查适用对象、扫描技术参数、辐射剂量范围、图像质量控制标准等方面进行讨论，共同制定了本共识。 结果 本共识定义肺癌筛查胸部LDCT的有效辐射剂量应≤1 mSv，并将受检者身体质量指数（body mass index，BMI）按照<18.5 kg/m²、18.5~24.9 kg/m²、≥25 kg/m²分为小BMI、中BMI和大BMI人群，推荐其管电压分别为≤100 kV、100~、120 kV，管电流量分别为20 mAs、30 mAs、30 mAs。重建卷积核建议为标准或中等大小。根据椎体棘突标志制定扫描范围，即当受检者BMI≥21 kg/m²时，扫描范围可从T1棘突上缘至T12棘突下缘，BMI<21 kg/m²时，扫描范围可控制为T1棘突上缘至L1棘突下缘；于深吸气末屏气扫描；推荐采用多平面重组、10 mm层厚最大密度投影、3 mm层厚最小密度投影、多层面容积重建进行图像后处理。 结论 本文对肺癌筛查胸部LDCT检查技术达成了全流程技术规范共识，有助于不同医疗机构之间同质化扫描，提升影像结果互认。

Objective To propose a standardized low-dose computed tomography（LDCT） protocol for lung cancer screening，and to provide guidance for rational and standardized application of LDCT for the detection and diagnosis of pulmonary nodules. Methods The experts from the Chinese Society of Imaging Technology participated in the formulation of technical specifications for LDCT lung cancer screening. This consensus was based on recent advances on LDCT lung cancer screening at home and abroad and the epidemiology of lung cancer in China，covering the applicable scope，scanning parameters，range of radiation dose，and image quality control standards. Results This consensus specifies that the effective dose of LDCT for lung cancer screening should be less than or equal to 1 mSv. According to the body mass index（BMI） of examinees，for small BMI（<18.5 kg/m²），medium BMI（18.5-24.9 kg/m²），and large BMI（≥25 kg/m²），the recommended tube voltages are ≤100 kV，100~120 kV，and 120 kV，respectively，and the recommended tube currents are 20 mAs，30 mAs，and 30 mAs，respectively. The reconstruction kernel is recommended to be standard or medium. Using the vertebral spinous processes as landmarks，the scanning range should be from the upper edge of the T1 spinous process to the lower edge of the T12 spinous process for examinees with BMI ≥21 kg/m² and from the upper edge of the T1 spinous process to the lower edge of the L1 spinous process for those with BMI <21 kg/m². Scanning should be performed using the breath-hold technique at the end of deep inspiration. The recommended image post-processing methods include multi-planar reconstruction，10-mm maximum intensity projection，3 mm minimum intensity projection，and multi-slice volume reconstruction. Conclusion This expert consensus on the whole process of LDCT for lung cancer screening can facilitate homogeneous scanning across different medical institutions，improving the mutual recognition of imaging results.