The role of chest CT in deciphering interstitial lung involvement: systemic sclerosis versus COVID-19
Martina Orlandi, Nicholas Landini, Gianluca Sambataro, Cosimo Nardi, Lorenzo Tofani, Cosimo Bruni, Silvia Bellando-Randone, Jelena Blagojević, Daniela Melchiorre, Michael Hughes, Christopher P. Denton, Fabrizio Luppi, Barbara Ruaro, Francesca Della Casa, Francesca Wanda Rossi, Giacomo De Luca, Corrado Campochiaro, Michele Spinicci, Lorenzo Zammarchi, Sara Tomassetti, Antonella Caminati, Edoardo Cavigli, Marco Albanesi, Fabio Melchiorre, Stefano Palmucci, Virginia Vegni, Serena Guiducci, Alberto Moggi Pignone, Yannick Allanore, Alessandro Bartoloni, Marco Confalonieri, Lorenzo Dagna, Francesco De Cobelli, Amato de Paulis, Sergio Harari, Dinesh Khanna, Masataka Kuwana, Gloria Taliani, Federico Lavorini, Vittorio Miele, Giovanni Morana, Alberto Pesci, Carlo Vancheri, Stefano Colagrande, Marco Matucci‐Cerinic
Abstract
OBJECTIVE: The aim of this study was to identify the main CT features that may help in distinguishing a progression of interstitial lung disease (ILD) secondary to SSc from COVID-19 pneumonia. METHODS: This multicentric study included 22 international readers grouped into a radiologist group (RADs) and a non-radiologist group (nRADs). A total of 99 patients, 52 with COVID-19 and 47 with SSc-ILD, were included in the study. RESULTS: Fibrosis inside focal ground-glass opacities (GGOs) in the upper lobes; fibrosis in the lower lobe GGOs; reticulations in lower lobes (especially if bilateral and symmetrical or associated with signs of fibrosis) were the CT features most frequently associated with SSc-ILD. The CT features most frequently associated with COVID- 19 pneumonia were: consolidation (CONS) in the lower lobes, CONS with peripheral (both central/peripheral or patchy distributions), anterior and posterior CONS and rounded-shaped GGOs in the lower lobes. After multivariate analysis, the presence of CONs in the lower lobes (P < 0.0001) and signs of fibrosis in GGOs in the lower lobes (P < 0.0001) remained independently associated with COVID-19 pneumonia and SSc-ILD, respectively. A predictive score was created that was positively associated with COVID-19 diagnosis (96.1% sensitivity and 83.3% specificity). CONCLUSION: CT diagnosis differentiating between COVID-19 pneumonia and SSc-ILD is possible through a combination of the proposed score and radiologic expertise. The presence of consolidation in the lower lobes may suggest COVID-19 pneumonia, while the presence of fibrosis inside GGOs may indicate SSc-ILD.