目的 回顾性分析细支气管肺泡 癌的低剂量CT表现，旨在提高细支气管肺 泡癌的诊断水平。方法 收集经手术病理 证实为BAC病例31例，分析其低剂量CT上 的表现。评价指标包括：病灶形态、边 缘、内部密度等特征以及有无淋巴结肿大 等；同时记录单次扫描的辐射剂量，并对 图像质量进行主观评分。结果 所有病灶 均表现为磨玻璃密度(GGO)结节，96.7％ 边界清晰，分叶征、毛刺征及空泡征的发 生率分别为93.5％、57％及54.8％，均无 肺门纵隔淋巴结转移。低剂量CT的平均辐 射剂量为(1.29±0.16)mSv，图像质量均 能满足临床诊断要求。结论 BAC具有特征 性的CT表现；低剂量CT在保证图像质量的 前提下，有效降低辐射剂量，对BAC的诊 断具有重要价值。

Objective To develop the diagnostic level of bronchioloalveolar carcinoma (BAC) by analyzing low dose CT presentations of BAC. Methods 31 cases of BAC confirmed by operation and pathology were retrospectively analyzed. Evaluated findings included the characteristics of lesions morphous, contours and density, lymphadenopathy were also assessed. Results All of the cases presented GGO nodules. 96.7％ of them showed well-defined margin. The rate of lobulated shape, spicule sign and gascontaining space were 93.5％, 57％, 54.8％, respectively and lymphadenopathy in none of these BAC. The image quality of low dose CT were acceptable in the clinical diagnosis. The average ED was (1.29±0.16)mSv. Conclusion BAC had CT features with characteristic. Low dose CT could maintain or improve image quality on chest CT while reducing radiation dose effectively, and had great value in diagnosis of BAC.