Modified lung ultrasound score to assess extent and prognosis in systemic autoimmune rheumatic disease-associated interstitial lung disease

Objectives Lung ultrasound (LUS) assesses lung lesion severity in systemic autoimmune rheumatic disease-associated interstitial lung disease (SARD-ILD). The ultrasound manifestations of SARD-ILD include pleural line (PL) abnormalities and heterogeneous B-line (BL) distribution. We aimed to investigate the feasibility of a modified ultrasound scoring system based on refined grading of BL and PL features in patients with SARD-ILD, to determine whether BLs and PLs can effectively reflect ILD patterns across different lung compartments. METHODS 195 Patients with nine SARD-ILDs underwent LUS-chest high-resolution computed tomography (HRCT) pairing was used to determine BLs and PLs diagnostic performance for ILD patterns characterization. BL and PL scores for both were refined to obtain the modified LUS score. Correlations with the Warrick score, ILD-GAP, and severity based on forced vital capacity (FVC) were analyzed, receiver operating characteristic (ROC) were calculated. RESULTS Using HRCT as a criterion, BLs and PLs showed high concordance for diagnosing ground-glass opacity (kappa = 0.606) and reticular opacity (kappa = 0.743), respectively. Modified LUS scores were positively correlated with the Warrick score (r = 0.863; p< 0.001) and ILD-GAP (r = 0.613; p< 0.005). ROC analysis revealed optimal modified LUS score thresholds of 11.5 for identifying cases with high fibrosis burden (Warrick score >8), 18.5 for high mortality risk (ILD-GAP ≥2), and 9.5 for severe functional impairment (FVC% predicted <60%). CONCLUSION BLs and PLs have different diagnostic significances for different ILD patterns. The modified LUS scoring system reliably assesses lesion severity and suggesting poor prognosis in SARD-ILD compared with computed tomography scan.