The Characters And Clinical Value Of Vibration Response Imaging In Healthy Subjects And Obstructive Lung Diseases Patients

Background Vibration response imaging(VRI)is a new lung sound imaging technology which shows the vibration in the lungs during respiratory period. Now clinical researches about VRI can been found all over the world.But no clinical report which study the VRI characters in healthy subjects and obstructive lung diseases patients can be found in China up to date.Objective First to value the clinical use of VRI device used in this research.Then our research was aimed to describe the characters of VRI in healthy subjects and chronic obstructive pulmonary disease(COPD) patients, and to explore the range of reference value in healthy people and its value in diagnosing COPD.VRI provides quantitative lung data(QLD)of vibration in respiratory period.The research also explored the value of QLD in diagnosing obstructive lung diseases such as COPD and asthma.Methods 66 healthy subjects received clinical examination,pulmonary function test(PFT) and VRI examination.63 COPD patients received clinical examination,PFT and VRI examination before and after inhalation of bronchodilator.The clinical use of VRI device was valued carfully.We defined VRI results as QLD of right lung,crack counts,and image grade. The results of two groups were described and analyzed seperately and then compared.In the retrospective research of QLD,the QLD of 64 healthy subjects, 61 COPD patients and 58 asthma patients in another research were reviewed. The QLD were transferred to abnormity and variation by a formulation,and the results were analyzed and compared between groups.Results 66 healthy subjects and 63 COPD patients received VRI examination for 576 times all together.The sensor successfully adsorbed in 97.7%subjects.Everyone can complete the examination and no adverse event(AE) was reported.Crack detectation was consistent with auscultation in 91.5%subjects.VRI results of healthy subjects have its characteres.The QLD of right lung was 45.1%±5.9%,mean crack counts 0.1,mean image grade 0.9.The range of reference value were as follows:(1) |QLD of right lung -45%|＜12%, (2) crack counts＜4,(3) image grade＜4,otherwise means abnormal.The specificity in this group was 90.9%.The VRI results of COPD patients were different from healthy people, and the results were similar before and after inhalation of bronchodilator (P＞0.05).After inhalation of bronchodilator,the QLD of right lung was 51.0%±12.1%,mean crack counts 2.7,image grade 4.2±1.9.There was a linear relationship between VRI image grade and FEV₁%(r=0.31,P=0.01).There was a statistical difference between COPD patients and healthy people(P＜0.01). The sensitivity in this group was 74.6%.The mean QLD of six regions in healthy subjects were(8.4,14.5,22.0, 11.1,18.5,25.5),mean abnormity 10.0,mean variation 2.0.Abnormity and variation in COPD patitients were similar before and after inhalation of bronchodilator(P＞0.05).After inhalation of bronchodilator,mean abnormity was 47.1,mean variation 10.9.The mean abnormity of asthma patients were 58.1,mean variation 12.2.But after inhalation of bronchodilator,mean abnormity decreased(P＜0.01).The abnormity and variation of patients were different from those of healthy subjects(P＜0.05).If we define normal as abnormity＜20.0 and variation＜5.0,the specificity was 87.5%.The sensitivity of COPD was 82.0%and the sensitivity of asthma was 82.8%.Conclusion VRI device is convenient and reliable,consistent with auscultation and no AE was reported.So it is competent for clinical use. VRI results of healthy people have its characteres.There was a statistical difference between the VRI results of COPD patents and healthy subjects and the VRI results in COPD patents were stable after inhalation of bronchodilator,thus were helpful in diagnosing COPD.The VRI image grade after inhalation of bronchodilator was useful to assess the degree of obstruction.Using abnormity and variation which were transformed from QLD by the formulation,most COPD and asthma patients can be found from healthy people and can be identified from each other.