Changes of quantitative CT indexes in chronic obstructive pulmonary disease patients and correlations with pulmonary function indicators / 中国医学影像技术

ABSTRACT

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(Ntotal/LSA),total number of vessels with area less than 5 mm2 per 1 cm2 of lung surface area(N＜5mm2/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,Ntotal/LSA and N＜5mm2/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％,Pi1o and entire volume of airway wall were negatively correlated with pulmonary function indicators(all P＜0.05),while Ntotal/LSA and N＜5 mm2/LSA were positively correlated with pulmonary function indicators(all P＜0.05).Conclusion CT quantitative parameters,including LAA％,Ntotal/LSA,N＜5mm2/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.