Mate rials and Methods Spirometrically gated HRCT scanning at carina, 5cm above and 5cm below carina at 100%VC and 90%VD was performed in patients and controls.

• 材料与方法 病例组及对照组在 10%25肺活量 (VC)和 90%25VC呼吸水平下于隆突层、隆突上、下各 5cm处行HRCT扫描。