Rheumatoid Arthritis–associated Interstitial Lung Disease: Radiologic Identification of Usual Interstitial Pneumonia Pattern

Abstract

Purpose:To determine the accuracy of computed tomography (CT) in identifying the histopathologic usual interstitial pneumonia (UIP) pattern in rheumatoid arthritis-associated interstitial lung disease (RA-ILD). Materials and Methods:All patients were enrolled into institutional review boardapproved longitudinal cohorts at their respective institution, and informed consent was obtained at the time of enrollment. Images of patients with surgical lung biopsyproved RA-ILD (n = 69) were collected from three tertiary care centers. Two experienced thoracic radiologists independently reviewed the CT scans. The CT pattern was categorized as definite UIP, possible UIP, or inconsistent with UIP in accordance with published criteria. Findings of biopsies were reviewed by an experienced lung pathologist. The sensitivity and specificity of definite CT UIP pattern to histopathologic UIP pattern were determined. The agreement between radiologists was assessed by calculating a k score. Results:The histopathologic UIP pattern was present in 42 of 69 (61%) patients. Men were more likely than women to have a histopathologic UIP pattern (P = .02). Twenty patients (29%, 20 of 69) had a definite UIP pattern on CT scans. The specificity of CT UIP pattern was 96% (26 of 27; 95% confidence interval [CI]: 81%, 100%), with a negative predictive value of 53% (26 of 49). The sensitivity of CT UIP pattern was 45% (19 of 42; 95% CI: 30%, 61%), with a positive predictive value of 95% (19 of 20).The agreement between radiologists for definite UIP pattern versus not was 87% (k = 0.67, P , .0001). Conclusion:Definite UIP pattern on a CT scan in RA-ILD is highly specific and moderately sensitive for histopathologic UIP pattern. CT can therefore help accurately identify the UIP pattern in RA-ILD.q RSNA, 2013

Automated Classification of Usual Interstitial Pneumonia Using Regional Volumetric Texture Analysis in High-Resolution Computed Tomography

“…Interestingly, the agreement between the computer and the consensus was comparable to the agreement between the fellows and the consensus, suggesting that while the algorithm can still be improved in terms of agreement with the consensus, the current method performs at least as well as cardiothoracic fellows. The performance was also consistent with the inter-reader agreement between two expert radiologists (i.e., 4 and 8 years of experience, kappa value of 0.67) reported by Assayag et al in [13]. Since the target application for this algorithm is for general radiologists, the proposed system could considerably improve their performance, a study which we plan to undertake.…”

“…Importantly, a confident CT diagnosis of UIP also requires the absence of atypical findings. The accurate identification of classic UIP requires meticulous characterization of parenchymal abnormalities as well as appropriate anatomic localization, mosty accurately performed by experienced thoracic radiologists [13]. The characterization of lung parenchymal abnormalities such as honeycombing, reticulation and ground glass requires the appreciation of subtle three-dimensional (3D) morphological tissue properties (e.g., parenchymal texture) shown in Figure 1.…”

Interobserver agreement for the ATS/ERS/JRS/ALAT criteria for a UIP pattern on CT

“…Thomeer et al 6 reported similar, low levels of agreement between three expert thoracic radiologists for a radiological diagnosis of typical UIP (κ w =0.40). Most recently, in a paper by Assayag et al ,17 CT appearances of 69 cases of biopsy proven rheumatoid-related interstitial lung were evaluated by two experienced thoracic radiologists applying a binary score of ‘definite UIP’ or ‘not’ (based upon current ATS/ERS/JRS/ALAT CT criteria), and reported a κ coefficient of 0.67 for this score. A limitation of these studies is that all, with the exception of one,17 predate the most recent diagnostic guidelines and therefore may not easily be interpreted in the context of current recommendations.…”

“…Most recently, in a paper by Assayag et al ,17 CT appearances of 69 cases of biopsy proven rheumatoid-related interstitial lung were evaluated by two experienced thoracic radiologists applying a binary score of ‘definite UIP’ or ‘not’ (based upon current ATS/ERS/JRS/ALAT CT criteria), and reported a κ coefficient of 0.67 for this score. A limitation of these studies is that all, with the exception of one,17 predate the most recent diagnostic guidelines and therefore may not easily be interpreted in the context of current recommendations. In addition, all employed small numbers of academic radiologists from tertiary referral centres with specific expertise in the evaluation of patients with IPF 5 6.…”

A case of pulmonary fibrosis associated with rheumatoid arthritis, scleroderma sine scleroderma and ANCA associated vasculitis.

“…RA-ILD patients, who have UIP, have a survival similar to that of matched subjects with IPF (Park et al 2007;Kim et al 2010). Data from idiopathic interstitial pneumonia (IIP) population show that HRCT chest can accurately predict the presence of histopathologic UIP pattern in a subset of patients (Hunninghake et al 2003) and several studies in RA-ILD have suggested similar specificity (Assayag et al 2014). So UIP pattern on HRCT is clinically relevant and all RA-ILD patients should undergo evaluation of their HRCT pattern.…”