Translated Abstract
Objective
(1)To evaluate the advantages of the different bronchial measuring methods respectively by analysising the concordance between different measuring methods of manual, semi-automatic and automatic and the concordance between reproducibility of three measuring methods respectively. (2)To investigate the influence on Quantitative CT and the risk factors with disease by analysising the correlation between parameters of Quantitative CT in normal and COPD separatedly the and to filter variables used for the diognosis of COPD by comparing the difference of Quantitative CT parameter between the normal and the COPD. (3)To evaluate the value of using Quantitative CT in diagnosing COPD by Bayes discriminatory analysis and to investigate the difference of the extent of airway alterations and emphysema among different grades of GOLD by depicting distribution of airway alterations and emphysema.
Materials and methods
The research contain three parts:
(1)The first part: People who came to our hospital to have lung cancer screening from June, 2013 to August, 2015 were recruited based on the inclusion and exclusion criteria strictly. The inclusion criteria: 1) Have lung cancer screening twice and have thoracic HRCT scans twice which interval time one scanner time to another have not to less ten to thirteen months; 2) have no pulmonary disease or other system diseases; 3)have no thoracic surgery; 4) have less dust exposure in working or dwelling environment. The exclusion criteria: 1) have poor breathing cooperation from subjects, have poor images; 2)the segment of bronchi is incomplete; 3)the ratio of the short diameter to long diameter is less than 2/3 when use the manual measurement method. The lumen diameter and the outer diameter of 194 of the selected bronchi were measured by two radiologists both using three methods of manual, semi-automatic and automatic. Take the average value of the bronchial measuring of the two radiologist as the final measuring result. Concordance of bronchial measurement between three methods as well as reproducibility of three methods was evaluated with Bland-Altman analysis. Investigate whether the computer-aided bronchial measurement is feasible and superior. All statistical analyses were performed using SPSS statistical software, version 18.0 for Windows.
(2)The second part: Our object contain two kinds of people: the normal and the patients of COPD. ①The normal: the people who performed lung function tests and came to our hospital to have lung cancer screening were recruited from March, 2014 to September, 2015. The inclusion criteria：1）have no respiratory symptoms ; 2) have no pulmonary disease or other system diseases; 3）have less dust exposure in working or dwelling environment; 4）the lung function tests is normal. The exclusion criteria: 1) the history of thoracic surgery; 2）malignancy received radiotherapy and chemotherapy; 3)younger than 40 or older than 80; 3) have poor breathing cooperation from subjects, have poor images. 4)the segment of bronchi is incomplete. ②The patient of COPD: The patient of COPD in hospital were recruited from March, 2014 to September, 2015. The inclusion criteria: 1) performed the lung function tests; 2)In accordance with diagnosis criteria on COPD made by China Medical Association(CMA) in 2013. The exclusion criteria: 1)combine with other pulmanory disease like asthma,pneumonia and so on; 2）malignancy received radiotherapy and chemotherapy; 3)younger than 40 or older than 80; 4) have poor breathing cooperation from subjects, have poor images; 5)the segment of bronch is incomplete; 6) can not coopetate with the lung function tests. The demographic database were collected and the images of scnner of thoracic HRCT were acquired , the images were transmitted to the Dexin-FACT and were analyzed by it. The results of Quantitative CT were record. Correlation analysis of Pearson and multiple linear regression were used to analyzed the correlation of the paratmeters of Quantitative CT and the demographic in normal and COPD separately. The difference of the normal and COPD of the paratmeters of Quantitative CT was peformed using Independent- Samples T test and Logistic regression( Statistical signifiance was set at p＜0.05). All statistical analysis were performed using SPSS statistical software, version 18.0 for Windows.
(3) The third part: the object of study is the same as the second part. The variables were filtered by stepwise discriminatory analysis further and the Bayes models were established. Then the discriminiatory analysis was perfomed. The accuracy was evaluated by cross validation and historical validation. The distribution of WA% and %LAA-950 among different grades of GOLD was depicted to exhibit the difference of the extent of airway alterations and emphysema among different grades of GOLD.
Results
1.The concordance between manual, semi-automatic, automatic measurement was good.
2.The reproducibility of manual, semi-automatic, automatic was good respectively. Compared with mannual measurement, the reproducibility of semi-automatic and automatic was better.
3.The correction of Pearson analysis showed that the total lung volume was positively related to the height whether in normal or in COPD(r=0.517,r=0.344;p＜0.001,p=0.007). In normal, the mean lung denstity was positively related to the height, but, it was not when in COPD. However, when the multiple linear regression was applied to control the covariate, both in normal and COPD the mean lung denstity was not related to the height. Therefore, the total lung volume was positively related to the height.
4.The %LAA-950 was negatively related to height and BMI(r=－0.339, r=－0.362; p=0.007, p=0.004) in COPD.
5.The WA/BSA was negatively related to height, BMI(rnormal=－0.662, rnormal=－0.772, p＜0.001, p＜0.001; rCOPD=－0.544, rCOPD=－0.605, p=0.024, p=0.010), and was positively related to cigarette amount( rnormal=0.359，p=0.009；rCOPD=0.228，p=0.018). The WT/√BSA was negatively related to height, BMI(rnormal=－0.555, rnormal=—0.0.672, p＜0.001, p＜0.001; rCOPD=－0.475, rCOPD=—0.526,p=0.036, p=0.012), and was positively related to cigarette amount( rnormal=0.402，p=0.005；rCOPD=0.327，p=0.021).
6.The Independent-Sample T test showed: at CT emphysema quantifiation, the group of COPD had signifiantly larger total lung volume and higher %LAA-950 than the group of normal (p＜0.001，p＜0.001)(after adjustment for confounder, the condition remained the same). the group of COPD had signifiantly mean lung density lower and less PD15 than the group of normal(p=0.038, p＜0.001).
7. The Independent-Sample T test of each bronchus showed: the group of COPD the lumen diameter of the 3th generation bronchus in inferior lobe of left lung and the 7th generation bronchus in inferior lobe of right lung was narrower than the group of normal(p=0.019, p＜0.001); the group of COPD the WA% of the 3th and the 7th generation bronchus in inferior lobe of right lung and the 3th generation bronchus in inferior lobe of left lung were larger than the group of normal(the value of p was 0.015, 0.002, 0.003 repectively); the group of COPD the WA/BSA of the 3th and 5th generation bronchus in middle lobe of right lung were larger than the group of normal(the value of p was 0.018,0.047 respectively); the group of COPD the WT/√BSA of the 4th generation bronchus in middle lobe of right lung, the 5th generation bronchus in middle superior lobe of right lung, the 6th and 7th generation bronchus in inferior lobe of right lung were larger than the group of normal(the value of p was 0.023, 0.036, 0.006, 0.007 respectively); the group of COPD the TDR of the 7th generation bronchus in inferior lobe of right lung, the 5th generation bronchus in superior lobe and the 3th generation bronchus in inferior lobe of left lung were larger than the group of normal(the value of p was 0.001,0.003,0.005 respectively).
8. The Independent-Sample T test of each generational bronchi showed: the group of COPD the lumen diameter of the 7th generation bronchi was narrower than the group of normal(p=0.015); the group of COPD the WA% of the 6th and the 7th generation bronchi were larger than the group of normal(the value of p was 0.027, 0.006 respectively); the group of COPD the WA/BSA of the 5th and 7th generation bronchi were larger than the group of normal(the value of p was 0.029, 0.026 respectively); the group of COPD the WT/√BSA of the 6th and 7th generation bronchi larger than the group of normal(the value of p was 0.017, 0.015 respectively); the group of COPD the TDR of the 7th generation bronchi was larger than the group of normal (the value of p was 0.033).
9. Six of the significant variables were filtered by stepwise discriminatory analysis, the Bayes models were established. The accuracy of historical was 86.92%, the predictability of normal was 89.7%, the predictability of COPD was 83.7%; the accuracy of cross validation was 85.05%, the predictability of normal was 89.7%, the predictability of COPD was 79.5%.
10.In the first distribution map, the GOLD II, III, IV were mainly distributed over the area of emphysema dominant, the area of mixed phenotypes mainly were mainly taken up by GOLD IV, the area of normal and airway dominant were taken by the normal. In the second distribution map, the GOLD II were mainly distributed over the area of emphysema dominant, the GOLD III were distributed over mixed phenotypes(slight), emphysema dominant, mixed phenotypes(heavy), GOLDIV were distributed over the area of airway dominant.
Conclusions
1.The computer-aided semi-automatic and automatic measument had the advantage over manunal measument. The automatic measument was suitable for diffuse airway disease, while the semi-automatic measument was suitable for local diffuse airway. They complement each other＇s advatages .
2.The height could influence the measuring of total lung volume.
3. The %LAA-950 was negatively related to weight and BMI. The more the %LAA-950 was, t the susceptible the one＇s emphysema might occur.
4. WA/BAS, WT/√BSA was positively related to cigarette amount. The more the one smoked, the thickness the bronchial wall was.
5.The group of COPD had larger total lung volume and higher %LAA-950 than the group of normal. It had lower mean lung density and less PD15 than the group of normal.
6. The group of COPD had thicker bronchial wall and narrower lumen diameter than the group of normal.The higer the generation was, the more obvious the different is.
7.It might be better measuring the mean of one higher generation of bronchial than measuring one bronchus.
8. Quantitative assessement of bronchi provided some value for diagnosing COPD .
9. Quantitative CT could reflect the pathological changes of the airways and lung parenchyma in patient of COPD. The higher the grade of GOLD, the serious the airways changed.
KEY WORDS: COPD; CT Quantitative; The value of diagnosis
TYPE OF THESIS: Application Research
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