Eighty-five patients with confirmed COVID-19 infection were included in this study. The clinical characteristics and laboratory results of these 85 patients are shown in Table 1. Of the 85 patients, 34 were women (40%) and 51 were boys or men (60%). The mean age was 45.35 ± 16.91 years.
Twenty-six patients had traveled to or resided in Wuhan and surrounding areas within 14 days before onset. Twenty-four patients had been in contact with patients who had confirmed COVID-19 infection within 14 days before onset. Nineteen patients had been exposed to patients with confirmed COVID-19 infection from Wuhan and surrounding areas, or to patients from other areas with confirmed infection who exhibited fever or respiratory symptoms. Sixteen patients had no clear epidemiological history.
The main clinical symptoms were fever in 76 patients, asthenia in 25 patients, and diarrhea in three patients. All patients had different respiratory symptoms: cough, sputum, and/or chest tightness. Laboratory examinations revealed that, in most patients, leukocyte count was normal (66/85, 78%) and neutrophil count was normal (81/85, 95%); however, lymphocyte count was low (42/85, 49%). C-reactive protein levels were elevated in 64/85 patients (75%). Moreover, 37 patients (44%) had low CD4+ cell count, ranging from 98–302 cells/µL.
In accordance with guidelines for the diagnosis and treatment of patients with COVID-19 infected pneumonia (trial sixth edition)5, clinical classifications were mild, moderate, severe, and critical. In our study, the respiratory tract samples of 85 patients were positive for 2019-nCoV nucleic acid. The clinical classifications were as follows: five patients (6%), including two women, had no obvious abnormality in the initial or follow-up lung CT (i.e., mild disease); they were 4–34 years of age at disease onset (mean age, 20.4 ± 11.17 years). Sixty patients (71%), including 29 women, exhibited moderate disease; they were 21–63 years of age at disease onset (mean age, 43.90 ± 13.69 years). Twenty patients (23%), including three women, exhibited severe disease; they were 21–91 years of age at disease onset (mean age, 56.00 ± 19.27 years). Most of the patients had underlying diseases: two had mitral stenosis, two had cerebral infarction, three had diabetes, and five had hypertension. There were no patients with critical disease in this study; all patients recovered and were discharged.
Five patients had no obvious abnormality in the initial or follow-up lung CT. The distribution and morphology of pulmonary lesions in other 80 patients, as determined by CT, are shown in Tables 2 and 3. In the initial CT images, there were 715 segments involving 80 patients. Eleven patients had fewer than five segments involved; 39 patients had 5–10 segments involved; 30 patients had more than 10 segments involved; and four patients had all segments of both lungs involved. In 73 of 80 (91%) patients, 421 of 715 (59%) lesions were distributed in the lower lobes of both lungs; in 77 of 80 (96%) patients, the lesions were distributed around the lung. The morphologies and densities of the lesions are depicted in Figures 1 and 2. GGO (nodular, patchy, and lamellar GGO) was observed in 67 of 80 (84%) patients; GGO with interlobular septal thickening was observed in 62 of 80 (78%) patients; GGO with consolidation was observed in 20 of 80 (25%) patients; air bronchogram was observed in 14 of 80 (18%) patients; and pleural effusion was observed in four of 80 patients.
In the short-term follow-up CT images, there were 940 pulmonary segments involving 80 patients. Six patients had fewer than five lung segments involved; 42 patients had 5–10 lung segments involved; 32 patients had more than 10 lung segments involved; and seven patients had all segments of both lungs involved. In 73 of 80 (91%) patients, 569 of 940 (60%) lesions were distributed in the lower lobes of both lungs; in 77 of 80 (96%) patients, the lesions were distributed around the lung. The morphologies and densities of the lesions were as follows: GGO was observed in 26 of 80 (33%) patients; GGO with interlobular septal thickening was observed in 72 of 80 (90%) patients; GGO with consolidation was observed in 47 of 80 (59%) patients; air bronchogram was observed in 31 of 80 (39%) patients; and pleural effusion was observed in three of 80 patients.
Comparison of images between patients with moderate disease and those with severe disease revealed the following findings. First, 238 lung segments (mean, 12 segments/patient) were involved in initial CT examinations of 20 patients with severe disease, while 324 lung segments (mean, 16 segments/patient) were involved in short-term follow-up CT examinations; in contrast, 477 lung segments (mean, eight segments/patient) were involved in initial CT examinations of 60 patients with moderate disease, while 616 lung segments (mean, 10 segments/patient) were involved in short-term follow-up CT examinations. Second, all patients in whom all lung segments of both lungs were involved during the initial and follow-up CT examinations exhibited severe disease. Third, CT images of 20 patients with severe disease revealed that the scope of lesions was significantly enlarged and multiple consolidations were present (Figure 3).
Crosstabulation in SPSS 20.0 was used to analyze pathological changes in the initial and follow-up CT images. We found that the proportion of images with pathological changes was significantly different between CT images taken before and after diagnosis (Pearson χ2 = 95.623, P < 0.001). Moreover, the proportion of images with pure GGO decreased on follow-up CT images, whereas there were increased proportions of images with internal grid opacity and solid area (Table 1).