A correlation study of CT and clinical features of different clinical types of COVID-19/ 新型冠状病毒肺炎不同临床分型间CT和临床表现的相关性研究

Objective: To investigate the CT and clinical features of COVID-19. Methods: Chest CT and clinical data of 103 patients who were confirmed as COVID-19 in January 2020 were collected retrospectively. According to diagnosis and treatment of COVID-19 (trial version 5), all the patients were classified into common(n=58), severe (n=36) and critical (n=9) types, and their clinical findings, laboratory examination and CT finding were analyzed. CT features included distribution, location, size, shape, edge, number and density of the lesion, percentage of pneumonia lesions of the whole lung and extra-pulmonary manifestations. The CT features among different clinical types were compared using χ 2test or Fisher's exact probability. Comparisons of age, duration from onset to CT examination, and percentage of pneumonic lesions to total lung volume among different types were performed by using analysis of variance (normal distribution) or Kruskal-Wallis rank sum test (non-normal distribution). Results: In terms of clinical manifestations, the patients with critical COVID-19 were more common in elderly men, with a median age of 65 years. Fever was the first symptom in 49 (84%) of 58 common patients, and also the first symptom in both severe and critical COVID-19 patients. The incidence of coughing in severe (25/36, 69%) and critical (6/9, 67%) COVID-19 patients was higher than that in common patients (20/58, 34%). All critical patients had dyspnea. CT showed the common COVID-19 was located in bilateral lung (40/58, 71%)with multiple (40/58, 69%), ground glass (31/58, 52%) or mixed (25/58, 43%)opacities (56/58, 97%), while all the severe and critical COVID-19 were located in bilateral lung(100%) with multiple (34/36, 96%), patchy (33 /36, 92%), or mixed opacities (26/36, 72%) in severe patients, and with mixed opacities more than 3 cm in critical patients. As for the percentage of pneumonia focus in the whole lung volume, the common type (12.5%±6.1%) was significantly lower than the severe type (25.9%± 10.7%) and the critical type (47.2%±19.2%), with statistically significant differences(P< 0.001 and 0.002 respectively), and the severe type COVID-19 was also significantly lower than the critical type (P= 0.032). Conclusions: CT and clinical features of different clinical types of COVID-19 pneumonia are different. Chest CT findings are characteristic, which can not only help the early diagnosis but also evaluate the clinical course and severity.