Quantitative Evaluation And Correlation Study Of Dual-energy CT Pulmonary Perfusion In Rheumatoid Arthritis Associated Interstitial Lung Disease

Objective To explore the value and significance of quantitative parameters of dual-energy CT pulmonary perfusion imaging in the evaluation of the condition and efficacy of rheumatoid arthritis related interstitial lung disease,as well as the correlation between quantitative parameters and serological indicators.Methods A total of 90 patients with rheumatoid arthritis-associated interstitial lung disease(RA-ILD)admitted to the Affiliated Hospital of Inner Mongolia Medical University from April 2021 to February 2023 were collected,and 30 patients with rheumatoid arthritis without interstitial lung disease(RA-NILD)were collected as control group.All patients underwent dual-energy CT pulmonary perfusion imaging and HRCT images were reconstructed on conventional chest plain scan images.Patients in the RA-ILD group received conventional treatment for 2 weeks and received dual-energy CT pulmonary perfusion imaging again.The anti-cyclic citrullinated peptide(CCP)antibody and sialoliquefactive carbohydrate antigen 6(KL-6)indexes of patients in the RA-ILD group before treatment were collected.The HRCT imaging findings of patients with RA-ILD were scored by two radiologists according to the Warrick scoring criteria,and the patients in the RA-ILD group were divided into mild group,moderate group and severe group according to the score.After the dual-energy CT pulmonary perfusion imaging scan was completed,the data were imported into the dual-energy lung analysis program of Siemens post-processing workstation.Based on the lung volume software,the whole lung can be automatically divided into five regions,namely,the upper and lower two regions of the left lung,and the upper,middle and lower three regions of the right lung.The region of interest(ROI)of about 0.5cm~2was delineated on the pulmonary trunk of the axial perfusion map,and the quantitative parameters of the study were automatically calculated by the normalized processing software:relative enhancement value(RE).The differences in quantitative parameters of dual-energy CT lung perfusion imaging among the four groups of subjects,the correlation between quantitative parameters and commonly used serological indicators in RA-ILD group,and the differences in quantitative parameters before and after treatment were analyzed.Results(1)There were four groups of subjects in this study,and there were no statistically significant differences in gender,age,and body mass index(BMI)between the groups(P>0.05).(2)There were significant differences in the total RE values of the whole lung and the RE values of each lung region between the RA-NILD group and the RA-ILD group(P<0.05).(3)The results showed that there were significant differences between the four groups in the total RE values of the whole lung and the RE values of each lung region(P<0.05).In the RA-ILD group,the RE values of each region decreased most significantly in both lower lungs.(4)The results showed that there was no statistical difference between the RA-NILD group and the mild group in total lung RE values among the four groups(P>0.05),while the other groups had statistical differences between the two groups(P<0.05).(5)The results of comparison among the four groups of RE values in each lung region showed that compared with the mild group,there was no significant difference in RE values in the five lung regions(P>0.05);Compared with the moderate group,the RE values of the five lung regions in the RA-NILD group were significantly different(P<0.05);Compared with the severe group,the RE values in the five lung regions in the RA-NILD group were significantly different(P<0.05);Compared with the moderate group,the RE values in the five lung regions were significantly different(P<0.05);Compared with the severe group,there were significant differences in RE values in the five lung regions(P<0.05);Comparison between the moderate group and the severe group:There was no significant difference in the RE values of the right upper and middle lung regions(P>0.05),while there were significant differences in the RE values of the right lower,left upper,and left lower lung regions(P<0.05).(6)Spearman correlation analysis showed that the total lung RE value,anti CCP antibody,and KL-6 levels in the RA-ILD group were negatively correlated with HRCT scores(P<0.001),while the anti CCP antibody,KL-6 levels were positively correlated with HRCT scores(P<0.001).(7)Spearman correlation analysis showed that there was a negative correlation between anti CCP antibodies,KL-6,and total lung RE values in the RA-ILD group(P<0.001).(8)After treatment,the RE values of each lung region and the total RE values of the whole lung in the RA-ILD group increased compared to those before treatment,with a statistically significant difference(P<0.05).Conclusion(1)The quantitative parameters of dual energy CT pulmonary perfusion imaging can quantify the pulmonary perfusion in patients with RA-ILD;(2)The quantitative parameters of dual energy CT pulmonary perfusion imaging have a good correlation with RA ILD serological indicators;(3)The quantitative parameters of dual energy CT pulmonary perfusion imaging can be used to evaluate the severity of the disease and the treatment effect in patients with RA-ILD.