Evaluation Of The Relationship Between Airway Remodeling And Severity Of Severe Asthma By Low Dose CT Scan

ObjectiveTo study the low-dose CT scanning of whole lung in patients with severe asthma.Using the lung reconstruction software Thoracic VCAR to measure the thickness of airway wall in patients with severe asthma and healthy subjects,and assessing the relationship between airway wall thickness with lung function,fractional exhaled nitric oxide?FeNO?and severity.Further study on the Clinical value of Low-dose CT scan in evaluating airway remodeling and severity of severe asthma.Methods1.According to GINA2015 criteria,29 patients with severe asthma were selected from our hospital outpatient service and 29 healthy subjects from medical examination center.After agreement of the subjects,Low-dose CT scan was performed in 29asthmatic patients and 29 normal subjects.The CT parameters are as follows:tube voltage 120 kV,tube current 30 mA,pitch 1.375:1,thickness 5mm,interlayer interval5mm.Image reconstruction through post-processing workstation,thickness 0.625 mm,interval 0.625 mm.2.The scanning images were reconstructed by Thoracic VCAR software.The measured datas included right superior lobar bronchus?RB₁?,right lower lobe bronchus(RB₁₀),subsegmental bronchus and left lower lobe bronchus(LB₁₀),subsegmental bronchus.Each set of bronchial measurements includes:lumen diameter?LD?,airway wall thickness?AWT?,lumen area?LA?,percentage of wall area?WA%?,wall thickness/airway diameter?WT/AD?.The mean values of the five parameters were calculated and divided by the value of body surface area?BSA?.And then statistical analysis.3.At the same time,the pulmonary function,exhaled nitric oxide?FeNO?and eosinophil count in blood were examined in patients with severe asthma.Records:FEV₁%pred,PEF,FEF_50%,FEF₂₅/_75%and other indicators.To analyze the correlation between airway indexes and other parameters in severe asthma group.Results1.The AWT,WT/AD and WA%of segmental bronchial parameters in severe asthma group are greater than normal control?P?0.05?,the WT/AD of submental bronchial parameters in asthma are larger than normal control?P?0.05?.2.There was a significant negative correlation between AWT and FEV₁ in patients with severe asthma.There was no significant correlation with age,course of disease,FEV₁/FVC%,FEF_25/75%and blood eosinophil count.ConclusionLow-dose CT scan can objectively reflect the airway remodeling in patients with severe asthma.The combination of whole lung Low dose CT and pulmonary function ventilation index can more comprehensively reflect the airway inflammation and disease control level in asthmatic patients.