呼吸门控定量CT对慢性阻塞性肺疾病的诊断价值

Spirometrically controlled quantitative CT for chronic obstructive lung disease

目的 用呼吸门控定量CT分析慢性阻塞性肺气肿、慢性支气管炎的平均肺密度 (MLD)和像素指数 (PI)的分布。方法 40例正常人、2 3例肺气肿病人及 15例慢性支气管炎患者 ,在 5 0 %肺活量 (VC)时用螺旋CT扫描全肺 ,在 10 %VC和 90 %VC时于隆突层及隆突上、下各 5cm处行高分辨率CT(HRCT)扫描 ,分析不同病种不同呼吸时相的MLD和 <- 910HU的肺区所占的比例 ,即PI的变化 ,并与肺功能 (PFTs)和形态学结果比较。结果 10 %VC时 ,肺气肿组与慢性支气管炎组的MLD降低 ,平均值分别为 - 831 8HU和 - 796 8HU ,与正常组为 - 745 3HU比较 ,统计学上差异有非常显著性意义 (P <0 0 1) ;90 %VC时 ,仅肺气肿组MLD下降 ,统计学上差异有显著性意义 (P <0 0 5 ) ;PI变化有同样规律 ,只是PI表现为增加。定量CT提示的病变与形态学一致 ,定量CT较肺功能敏感 ,呼气末定量CT还可以弥补CT形态学发现率低的不足。结论 CT与定量CT结合实现了形态与功能的统一 ,可以提供更多的诊断信息 ,完善疾病的诊断。

Objective To analyze the mean lung density (MLD) and pixel index (PI) of emphysema and chronic bronchitis using spirometrically controlled quantitative CT. Methods Forty healthy adults, 23 patients with emphysema, and 15 patients with chronic bronchitis performed lung spiral scans at 50% vital capacity (VC), and HRCT sections were acquired at carina and carina±5 cm at 10% VC and 90% VC. Results At 10% VC, the MLD in patients with emphysema and chronic bronchitis decreased (the MLD were-831.8 HU and -796.8 HU, respectively) compared to healthy adults (-745.3 HU)(P<0.01). At 90% VC, only the MLD in patients with emphysema significantly decreased (P<0.05). PI had the same feature as MLD, but it increased. The lesions detected by quantitative CT were consistent with that demonstrated by morphology. Quantitative CT was more sensitive than PFTs. The quantitative parameters of 10% VC could detect chronic bronchitis even when CT indicated normal results. Conclusion The combination of CT and quantitative CT can accomplish the unity of morphology and function, thus offer more diagnostic clues and make the diagnosis perfect.