目的：对比分析两种不同方向的肺部螺旋ＣＴ扫描的图像质量。方法：随机选择１００例肺部扫描的患者，进行从头→足和足→头两种方向扫描，两组图像按有无呼吸运动伪影、对比剂伪影来评定质量。结果：两组图像质量存在明显的差异。结论：肺部螺旋ＣＴ扫描时，采用由足→头方向扫描，能够获得更好的满足诊断要求的ＣＴ图像。 OBJECTIVE: To compare and analyze the image quality of lung spiral CT in two different directions. Methods: 100 cases of lung scans were randomly selected and scanned from head to foot and foot to the first two directions. The images of both groups were evaluated for the presence or absence of respiratory motion artifacts and contrast artifacts. Results: There was a significant difference in image quality between the two groups. CONCLUSIONS: Spiral CT scans with CT scanning from foot to head provide better CT images that meet the diagnostic criteria.