Quantitative-analysis of computed tomography in COVID-19 and non COVID-19 ARDS patients: A case-control study

PURPOSE: The aim of this study was to assess whether the computed tomography (CT) features of COVID-19 (COVID+) ARDS differ from those of non-COVID-19 (COVID−) ARDS patients. MATERIALS AND METHODS: The study is a single-center prospective observational study performed on adults with ARDS onset ≤72 h and a PaO(2)/FiO(2) ≤ 200 mmHg. CT scans were acquired at PEEP set using a PEEP-FiO(2) table with VT adjusted to 6 ml/kg predicted body weight. RESULTS: 22 patients were included, of whom 13 presented with COVID-19 ARDS. Lung weight was significantly higher in COVID− patients, but all COVID+ patients presented supranormal lung weight values. Noninflated lung tissue was significantly higher in COVID− patients (36 ± 14% vs. 26 ± 15% of total lung weight at end-expiration, p < 0.01). Tidal recruitment was significantly higher in COVID− patients (20 ± 12 vs. 9 ± 11% of VT, p < 0.05). Lung density histograms of 5 COVID+ patients with high elastance (type H) were similar to those of COVID− patients, while those of the 8 COVID+ patients with normal elastance (type L) displayed higher aerated lung fraction.