慢性阻塞性肺疾病CT定量参数改变及其与肺功能指标的关系

目的 观察未经治疗COPD患者CT定量参数变化及其与肺功能指标的关系。方法 回顾性分析99例未经治疗COPD患者资料；根据气流受限程度分为A组(GOLD 1级，轻度受限，36例)、B组(GOLD 2级，中度受限，37例)及C组(GOLD 3、4级，明显受限，26例);分析首检及随访胸部CT定量参数、肺功能指标的差异及其相关性。CT定量参数包括全肺容积、低衰减区百分比(LAA%)、肺血管总计数与肺表面积比值(N_total/LSA)、截面积<5 mm²的肺血管计数与肺表面积比值(N_{<5 mm²}/LSA)、理论气道内周长为10 mm的管壁面积平方根(Pi10)、全肺气道壁体积、壁厚及壁面积百分比(WA%)等，而肺功能指标包括吸入支气管舒张剂后第1秒用力呼气容积(FEV₁)、用力肺活量(FVC)及二者比值(FEV₁/FVC)和FEV₁率(FEV₁%)。结果 相比首检各项指标，随访时各组FVC、FEV_...

Changes of quantitative CT indexes in chronic obstructive pulmonary disease patients and correlations with pulmonary function indicators

Objective To observe changes of CT quantitative indexes in patients with untreated chronic obstructive pulmonary disease (COPD) and relationships with pulmonary function indicators. Methods Totally 99 patients with untreated COPD were retrospectively enrolled. According to the degrees of airflow obstruction, the patients were divided into group A (GOLD grade 1 with mild obstruction, n=36), group B (GOLD 2 with moderate obstruction, n=37) and group C (GOLD 3 or 4 with obvious obstruction, n=26). The results of chest CT and pulmonary function tests conducted at the first diagnosis and the follow-up, as well as their correlations were analyzed. CT quantitative indicators included the whole lung volume, low-attenuation areas less than -950 percentage (LAA%), total number of vessels per 1 cm² of lung surface area (N_total/LSA), total number of vessels with area less than 5 mm² per 1 cm² of lung surface area (N_{<5 mm²}/LSA), the square root of the wall area of a hypothetical airway with a 10 mm internal perimeter (Pi10), the entire volume, wall thickness and wall area percentage (WA%) of airway wall, etc., while results of pulmonary function tests included the forced expiratory volume in one second (FEV₁) after administration of a bronchodilator, forced vital capacity (FVC), the ratio FEV₁/FVC and FEV₁ expressed as percent predicted (FEV₁%). Results Compared with those at the first diagnosis, the follow-up results of FVC, FEV₁, FEV₁/FVC, N_total/LSA and N_{<5 mm²}/LSA were lower, whereas LAA%, Pi10 and entire volume of airway were all higher in each group (all P<0.05). Compared with those in group A, group B and C had decreased LAA% and increased Pi10, and the magnitude increased with the severity of airflow obstruction (all P<0.05). LAA%, Pi10 and entire volume of airway wall were negatively correlated with pulmonary function indicators (all P<0.05), while N_total/LSA and N_{<5 mm²}/LSA were positively correlated with pulmonary function indicators (all P<0.05). Conclusion CT quantitative parameters, including LAA%, N_total/LSA, N_{<5 mm²}/LSA, Pi10 and entire volume of airway wall were related to pulmonary function, which might reflect the longitudinal changes of airways and blood vessels in COPD patients.