| Interstitial lung disease(ILD)is a general term for a group of heterogeneous lung interstitial lesions with different etiologies,ILD is the most common pulmonary complication of connective tissue disease(CTD),which seriously affects the quality of life and survival time of CTD patients.Early recognition and timely treatment of ILD can better improve the survival prognosis of CTD.In recent years,new imaging techniques for early recognition of ILD have been continuously developed,but in clinical practice,thin-reconstruction of volumetric data with HRCT is still used as the main means for early diagnosis and disease assessment of ILD.Because CTD patients with ILD do not have a high incidence period,there is no high specificity of serological markers,and respiratory symptoms are often more severe ILD patients,so it is necessary to follow up closely throughout the course of the disease,and frequent screening for ILD in patients with high-risk factors will lead to most CTD patients need to undergo multiple HRCT examinations,and its cumulative radiation exposure is a risk that cannot be underestimated,and it is also the main clinical concern and shortcoming of the application of volumetric scanning HRCT.Radiation-free imaging screening tools have become the focus of research,most of which focus on lung ultrasonography(LUS)and serum biomarkers such as salivary liquefied glycoantigen 6(krebs von den Lungen-6,KL-6)in patients with ILD.Objective: To investigate the diagnostic efficacy of nine slices axial HRCT(9s HRCT)in CTD-ILD,and to further investigate the diagnostic value of 9s HRCT in different image types and different affected ranges of onnective tissue disease-associated interstitial lung disease(CTD-ILD).In recent studies,by changing the HRCT volume scanning mode to axial scanning,and reducing the number of scanning slices,the scanning density is concentrated in the base of the double lungs,namely 9 slices HRCT(9s HRCT),which are the most prevalent sites in ILD.This scanning protocol has high diagnostic value in interstitial lung disease in systemic Sclerosis(SSc-ILD),and still has high diagnostic accuracy in small ILD affected areas.And the radiation dose can be significantly reduced on the premise of ensuring the image quality.However,there are no studies on the diagnostic value of 9s HRCT in other types of CTD-ILD other than SSc-ILD,and no studies on the diagnostic.Method: CTD patients admitted to the our department from January 1,2022 to January 1,2023 for HRCT examination were included,and the results of chest HRCT examination were used as the gold standard for ILD diagnosis.There were 80 CTD combined ILD groups and30 CTD uncombined ILD groups according to whether there were any combined ILD groups.All enrolled patients underwent were nine slides HRCT(9s HRCT),LUS and serum KL-6examination.The sensitivity,specificity,negative predictive value and positive predictive value of 9s HRCT,LUS and serum KL-6 were calculated respectively,and their consistency with standard volume HRCT diagnosis was compared.To further analyze and compare the diagnostic value of various diagnostic tools for different imaging subtypes and different affected ranges of CTD-ILD.Differences in radiation dose of 9s HRCT versus standard HRCT were calculated and compared.Results:1.The sensitivity of 9s HRCT for the diagnosis of CTD-ILD was 88.8%(95%CI 79.2%,94.4%)and specificity of 93.3%(95%CI 76.5%,98.8%),which was highly consistent with the volume scanning HRCT(Kappa 0.765).LUS used the 14-rib space exploration method to use the B-line > 10 as the cut-off value for LUS to diagnose ILD,the diagnostic value of LUS was slightly inferior to that of 9s HRCT,its sensitivity was 81.3%(95% CI 70.6%,88.8%),the specificity was 86.7%(95% CI 68.4%,95.6%),and it was moderately consistent with standard HRCT,Kappa=0.765(P<0.001).Taking KL-6≥500U/ml as the cut-off value for diagnostic ILD,all evaluation indexes of single KL-6 diagnostic CTD-ILD were low,with a sensitivity of 66.3%(95% CI 54.7%,76.2%),a negative prediction of 48.1%(95% CI 34.2%,62.2%),and a consistency coefficient of 0.403 with standard HRCT kappa.2.The value analysis of various screening and diagnostic techniques in different imaging subtypes of ILD found that 9s HRCT had a strong ability to identify ILD in all types of ILD,the sensitivity for diagnosing ILD in non-specific interstitial pneumonia(NSIP),usual interstitial pneumonia(UIP),possible UIP and organic pneumonia(OP)was 87.80%,100%,80% and 75%,respectively,and there was no significant difference between groups(P=0.123).The sensitivity of LUS for the diagnosis of ILD in NSIP,UIP and possible UIP was78.05%,100% and 80%,respectively,but only 25% in OP,and there were significant statistical differences between the groups(P=0.004).Further within-group comparisons showed that LUS was significantly less sensitive than UIP in diagnosing OP(P=0.002).The diagnostic sensitivity of serum KL-6 assay(cut-off≥500 U/ml)in NSIP,UIP,possible UIP and OP was 66.85%,75%,60% and 50%,respectively,and there was no significant difference between groups(P=0.689).3.The value analysis of various screening diagnostic techniques in different ILD affected ranges showed that 9s HRCT had higher diagnostic sensitivity in different ILD affected ranges,95.83%,88.89% and 82.76% in the affected ranges ≥20%,5-20% and <5%,respectively,and the difference was not statistically significant(P=0.368).The sensitivity of LUS in the affected range of ≥20%,5-20% and <5% to diagnose ILD were 95.83%,93.59% and 58.62%,respectively,with statistically significant difference between groups(P=0.001),and further intra-group comparisons showed that LUS was in the affected range The diagnostic sensitivity at <5% was significantly lower than that of ≥20%(P=0.002)and 5-20%(P=0.003),and the difference was statistically significant.In the affected range<5% of the diagnostic sensitivity of various examination tools was statistically different(P=0.011),and the intra-group comparison found that the diagnostic sensitivity of HRCT was better than that of LUS,and the difference was statistically significant(P=0.082).The sensitivity of KL-6 for the diagnosis of ILD in the affected range ≥20%,5-20% and <5% was 83.33%,70.37% and 48.28%,respectively,and the difference was statistically significant(P=0.028),and further intra-group comparisons showed that the sensitivity of KL-6 for the diagnosis of ILD was significantly lower than that of 5-20%(P=0.026)and ≥20%(P=0.008)in the affected range <5%,and the difference was statistically significant.4.9s HRCT+KL-6 did not increase 9s HRCT specificity in the diagnosis of ILD,but only slightly improved sensitivity.However,there was no significant difference in diagnostic sensitivity between the two in different imaging subtypes and different ranges of ILD.5.In standard volume scanning HRCT,the mean dose length product(DLP)of radiation exposure was 320.32±73.35 m Gy.cm,and the effective dose was 4.48±1.03 m Sv,while the mean DLP of 9s HRCT was 32.74±3.08 m Gycm.The effective radiation dose was0.46±0.043 m Sv(P<0.001).Conclusion: 9s HRCT has a high diagnostic value for CTD-ILD screening and has a high consistency with standard-volume HRCT.The diagnostic value of 9s HRCT was not affected by the type of ILD and the range of involvement,and the diagnostic value was better than that of LUS and KL-6 in OP-type ILD,and the ability to identify ILD was particularly outstanding when the range of involvement was <5%.The radiation dose was significantly lower than that of standard volumetric HRCT.9s HRCT holds promise as the tool of choice for early screening of CTD-ILD. |
PDF Full Text Request