Application And Differential Diagnosis Value Of Image Post-processing System Quantitative Analysis In Chronic Obstructive Airway Disease

ObjectiveThe purpose of this study was to investigate the difference of HRCT features in patients with chronic obstructive airway diseases including chronic obstructive pulmonary disease(COPD),asthma-COPD overlap(ACO)and asthma with airflow limitation(asthma FL +)and its value in the differential diagnosis of three kinds of diseases.MethodsThe clinical data of patients with COPD,ACO and asthma FL + diagnosed in the outpatient department of respiratory department of Changhai Hospital and Huangpu branch of the Ninth People’s Hospital Affiliated to Shanghai Jiaotong University from January 2018 to June 2019 were analyzed retrospectively,including 36 patients in COPD group,34 patients in ACO group and 23 patients in asthma FL + group.The high-resolution chest CT images of all patients were quantitative analyzed automaticly by the image post-processing system(SYNAPSE 3D、Mimics20.0).The airway area(Ai),airway wall area percentage(WA%),airway wall thickness percentage(WT%)of the third to fifth stage(3rd-5th)and emphysema index were measured and compared between three groups.The severity of emphysema in the three groups was evaluated by two evaluation methods: SYNAPSE 3D emphysema index(Goddard)and mimics emphysema index scores(%),compare their correlation.The correlation between these indexes and pulmonary function value(FEV1 / FVC)was analyzed.The differential diagnosis value of these indexes in these three diseases was evaluated by the method of receiver operating curve(ROC).Results1.There was no significant difference in the 3rd-5th airway area(Ai)among the three groups;the percentage of 3rd-5th airway wall area(3rd-5th WA%)in Asthma FL +group was significantly higher than that in COPD group and ACO group(P < 0.05);the percentage of 3rd and 5th airway wall thickness(3rd,5th WT%)in Asthma FL + group was significantly higher than that in COPD group and ACO group(P < 0.05).The Godard and mimics emphysema index scores(%)in COPD group were higher than those in ACO group and Asthma FL + group,the difference was statistically significant(P <0.001;P < 0.001);Spearman correlation test was performed between the Godard and mimics emphysema index scores of the three groups,and the correlation was significant(r = 0.766,P < 0.001).The total airway count(TAC)of 5th-7th in Asthma FL + group was higher than that in COPD group and ACO group(P < 0.001,P < 0.001).There was no significant difference in TAC between COPD and ACO in any airway of offspring(P > 0.05).2.The 5th WA% and WT%)of COPD,ACO and asthma FL + patients was negatively correlated with FEV1 / FVC(r =-0.514,P = 0.001;r =-0.499,P = 0.002),(r =-0.402,P = 0.001;r =-0.358,P = 0.002),(r =-0.454,P = 0.03;r =-0.489,P = 0.018).The Goddard score and mimics emphysema index of ACO patients had significant correlation with FEV1/FVC(r =-0.393,P = 0.022;r =-0.564,P = 0.001).The 3rd-7th TAC of COPD patients was positively correlated with FEV1/FVC,and the correlations were statistically significant(r =-0.333,P = 0.047;r = 0.617,P < 0.001;r = 0.799,P <0.001;r = 0.419,P = 0.011;r = 0.624,P < 0.001);the 5th-7th TAC of ACO patients was positively correlated with FEV1/FVC,and the correlations werestatistically significant(r= 0.492,P = 0.003;r = 0.569,P < 0.001;r = 0.476,P = 0.004);the 3rd,4th,6th TAC of asthma FL + patients were positively correlated with FEV1-/-FVC and he correlations were statistically significant(r = 0.536,P = 0.008;r = 0.600,P = 0.002;r = 0.0489,P =0.018).3.Receiver operator characteristic curve(ROC)analysis showed that the combination of 3th WT% + 5th WA% had a good differential value between ashma FL +and ACO(AUC = 0.744,P = 0.002,sensitivity 82.4%,specificity 60.9% and Youden index 0.432).Godard index had better differential diagnosis value between COPD and ACO(AUC = 0.777,P < 0.001).The best cut-off value was 9.5,the sensitivity was92.7%,the specificity was 55.9%,and the Youden index was 0.531.The best cut-off value was 37.5,the sensitivity was 95.7%,the specificity was 91.2%,and the Youden index was 0.868.ConclusionThere were some differences in HRCT findings among COPD,asthma with airflow limitation and asthma COPD overlap groups,The correlation between proximal airway parameters and emphysema index and pulmonary function in patients with ACO is more significant and unique.The automatic quantitative measurements of 3rd WT% combined with 5th WA%,emphysema index and loss of airway number are helpful for the diagnosis of COAD subtypes.Several certain quantitative indicators could be used as potential clinical predictive value to evaluate the severity of airflow restriction in patients who cannot complete the lung function test.