An analysis of the radiological factors associated with respiratory failure in COVID-19 pneumonia and the CT features among different age categories

Purpose: To investigate CT patterns of COVID-19 pneumonia associated with respiratory failure (RF) focused on the distribution of lesions. Materials and methods: Eighty-five patients with COVID-19 pneumonia were reviewed. CT findings were classified as follows: Type A; patchy ground glass attenuation (GGA) with/without air-space consolidation, Type B; non-segmental GGA with/without air-space consolidation in both the central and peripheral lung portions especially with subpleural spare, and Type C; non-segmental GGA with/without air-space consolidation predominantly distributed in the peripheral lung portion without subpleural spare. We analyzed CT patterns and clinical factors associated with RF, including age categories. Results: The number of patients with Type A, B and C was 31 (37%), 24 (28%) and 30 (35%), respectively. Type C and hypertension were independently associated with RF. On comparing between Types B and C, the frequency of traction bronchiectasis was higher in Type C than in Type B (P < 0.001). The ratio of Type C in patients ≥ 65 years old (66%) was higher than in patients < 40 years old (P < 0.001) and 40–49 years old (P = 0.001). Conclusion: The Type C, increasing with age, was associated with RF. Traction bronchiectasis in the lesion was more frequent in Type C than in Type B. Secondary abstract A lesion adjacent to the pleura and hypertension is associated with respiratory failure in patients with COVID-19. The frequency of a lesion adjacent to the pleura increased with age. The distribution of lesions is a useful parameter to predict respiratory failure.