Demographic and clinical characteristics
The demographic and clinical characteristics of patients are listed in Table 1. There were 34 cases of the moderate group (mean age, 44±12 years; age range, 21-69 years) and 16 cases of the severe and critical group (mean age, 50±14 years; age range, 33-74 years). There was no significant difference in age, gender, and symptoms with fever and cough between the severe and critical group and the moderate group (all p >0.05). There was a significant difference in exposure history between the severe and critical group and the moderate group (16/34 vs. 16/16, p <0.001). The hospitalized period and numbers of scan in the severe and critical group were higher than that in the moderate group (28±7 vs. 20±8, p=0.002; 6±1 vs. 4±1, p <0.001, respectively). There was no significant difference in the consistency of PCR and CT results at the initial presentation between the two groups.
Table 1. Demographic and clinical characteristics
|
All patients (n=50)
|
Moderate type (n=34)
|
Severe and critical type (n=16)
|
t or c2 P-value
|
Age (years)
|
46±13 (21-74)
|
44±12 (21-69)
|
50±14 (33-74)
|
0.080
|
Gender
|
|
|
|
0.952
|
Man
|
29
|
20
|
9
|
|
Woman
|
22
|
15
|
7
|
|
Exposure history
|
|
|
|
<0.001***
|
Recent travel to Wuhan
|
32 (64%)
|
16 (47%)
|
16 (100%)
|
|
Exposure to infected patient
|
18 (36%)
|
18 (53%)
|
0 (0%)
|
|
Symptoms
|
|
|
|
|
Fever
|
31 (62%)
|
20 (61%)
|
11 (69%)
|
0.500
|
Cough
|
29 (58%)
|
17 (50%)
|
12 (75%)
|
0.095
|
Initial RT-PCR test and CT
|
|
|
|
1.000
|
Both RT-PCR and CT positive
|
46 (92%)
|
31 (91%)
|
15 (94%)
|
|
RT-PCR negative and CT positive
|
4 (8%)
|
3 (9%)
|
1 (6%)
|
|
The hospitalized period (d)
|
23±8 (10-43)
|
20±8 (10-40)
|
28±7 (19-43)
|
0.002**
|
Mean number of scans
|
4±2 (2-8)
|
3±1 (2-5)
|
6±1 (3-8)
|
<0.001***
|
The interval between the adjacent scans (d)
|
5±3 (2-10)
|
5±2 (2-13)
|
5±2 (1-10)
|
NA
|
Note: Quantitative data were presented as mean ± standard deviation (minimum-maximum), while the counting data were presented as count (percentage of the total).
NA, not applicable; ** p<0.01; *** p<0.001.
The findings of CT severity scores with CT follow-up time in the two groups
In the initial CT, the CT severity scores of right upper, middle and lower lobe in the severe and critical group was higher than that in the moderate group (1.7±1.4 vs. 0.7±0.5, 1.3±1.3 vs. 0.4±0.5, 1.9±1.2 vs. 1.2±0.7; all p <0.05, Table 2). There were no significant differences in the CT scores of left upper and lower lobe between the two groups (all p >0.05, Table 2). There were no significant differences in the number of involved lobes between the two groups (all p >0.05). The total CT severity score of the severe and critical group in the initial CT and follow-up CT was significantly higher than that of the moderate group (all p<0.05, Table 3). There were no significant differences in the interval time of Interval-1, Interval-2, Interval-3, and Interval-4 between the two groups (all p >0.05, Table 3).
Table 2. Different findings of initial CT images between two clinical groups
|
All patients (n=50 )
|
Moderate type (n=34)
|
Severe and critical type (n= 16)
|
Mann-Whitney U or c2 P-value
|
CT characteristics
|
|
|
|
|
ground glass opacity
|
44 (88%)
|
32 (94%)
|
12 (75%)
|
0.074
|
consolidation
|
24 (48%)
|
14 (41%)
|
10 (63%)
|
0.227
|
crazy-paving pattern
|
25 (50%)
|
17 (50%)
|
8 (50%)
|
1.000
|
pleural thickening or adhesion
|
26 (52%)
|
17 (50%)
|
9 (56%)
|
0.767
|
fibrosis
|
16 (32%)
|
10 (29%)
|
6 (38%)
|
0.746
|
discrete nodules
|
4 (8%)
|
3 (9%)
|
1 (6%)
|
1.000
|
bronchiectasis
|
3 (6%)
|
2 (6%)
|
1 (6%)
|
1.000
|
thoracic lymphadenopathy
|
2 (4%)
|
1 (3%)
|
1 (6%)
|
0.542
|
pleural effusion
|
2 (4%)
|
0 (0%)
|
2 (13%)
|
0.098
|
cavitation
|
1 (2%)
|
1 (3%)
|
0 (0%)
|
1.000
|
Number of involved lobes
|
|
|
|
|
Right upper lobe
|
34 (68%)
|
21 (62%)
|
13 (81%)
|
0.208
|
Right middle lobe
|
24 (48%)
|
13 (38%)
|
11 (69%)
|
0.069
|
Right lower lobe
|
46 (92%)
|
31 (91%)
|
15 (94%)
|
1.000
|
Left upper lobe
|
34 (68%)
|
22 (74%)
|
12 (75%)
|
0.533
|
Left lower lobe
|
39 (78%)
|
24 (71%)
|
15 (94%)
|
0.080
|
CT score in each lobe
|
|
|
|
|
Right upper lobe
|
1.0±1.0 (0-4)
|
0.7±0.5 (0-1)
|
1.7±1.4 (0-4)
|
0.017*
|
Right middle lobe
|
0.7±1.0 (0-4)
|
0.4±0.5 (0-1)
|
1.3±1.3 (0-4)
|
0.007**
|
Right lower lobe
|
1.5±1.0 (0-4)
|
1.2±0.7 (0-4)
|
1.9±1.2 (0-4)
|
0.047*
|
Left upper lobe
|
1.0±1.1 (0-4)
|
0.7±0.6 (0-2)
|
1.6±1.5 (0-4)
|
0.057
|
Left lower lobe
|
1.3±1.1 (0-4)
|
1.1±0.8 (0-3)
|
1.8±1.4 (0-4)
|
0.123
|
The total CT severity scores
|
5.6±4.4 (0-20)
|
4.1±2.3(0-11)
|
8.7±5.8 (1-20)
|
0.008**
|
Note: Quantitative data were presented as mean ± standard deviation (minimum-maximum), while the counting data were presented as count (percentage of the total). * p<0.05; ** p<0.01.
Table 3. The difference of CT severity scores and CT follow-up time between two groups
|
Moderate type (number of patients)
|
Severe and critical type (number of patients)
|
P-value by Mann-Whitney U test
|
Initial CT
|
4.1±2.3 (0-11) (n=34)
|
8.7±5.8 (1-20) (n=16)
|
0.008**
|
First follow-up CT
|
4.8±2.4 (1-10) (n=34)
|
11.3±5.5 (5-19) (n=16)
|
<0.001***
|
Second follow-up CT
|
5.0±2.7 (1-10) (n=28)
|
12.1±5.5 (7-20) (n=16)
|
<0.001***
|
Third follow-up CT
|
4.9±2.5 (0-9) (n=15)
|
11.7±5.4 (6-20) (n=15)
|
0.001**
|
Fourth follow-up CT
|
4.0±1.6 (0-8) (n=8)
|
10.6±5.4 (4-20) (n=14)
|
0.002**
|
Fifth follow-up CT
|
NA
|
8.7±5.5 (4-20) (n=8)
|
NA
|
Sixth follow-up CT
|
NA
|
4.7±0.6 (4-5) (n=4)
|
NA
|
Seventh follow-up CT
|
NA
|
4.0±0.0 (3-4) (n=2)
|
NA
|
Interval-1 (d)
|
4±2 (2-10)
|
4±2 (1-8)
|
0.518
|
Interval-2 (d)
|
9±3 (5-13)
|
8±3 (4-13)
|
0.102
|
Interval-3 (d)
|
14±4 (9-23)
|
12±3 (8-18)
|
0.251
|
Interval-4 (d)
|
17±2 (14-19)
|
17±4 (12-26)
|
0.743
|
Interval-5 (d)
|
NA
|
21±3 (19-26)
|
NA
|
Interval-6 (d)
|
NA
|
25±7 (18-36)
|
NA
|
Interval-7 (d)
|
NA
|
29±4 (24-32)
|
NA
|
Note: Quantitative data were presented as mean ± standard deviation (minimum-maximum), Interval-1, the interval between initial CT and first follow-up CT; Interval-2, the interval between initial CT and second follow-up CT, and so on. NA, not applicable; d, day.
** p<0.01; *** p<0.001.
There was a quadratic curve between the total CT severity score and CT follow-up times in the severe and critical group by the SPSS curve estimation module (r2=0.137, p=0.008, figure 1). The total CT severity score in the severe and critical group peaked at the second follow-up CT (12.1±5.5, range 7 to 20) with a mean interval of 8±3 days after the initial CT scan, and then gradually decreased. In the moderate group, there was no correlation between the total CT severity score and CT follow-up times by the SPSS curve estimation module (p >0.05, figure 1).
The findings of CT characteristics in the two groups
Among 50 patients, the occurrence rate of CT characteristics were GGO (88%), pleural thickening or adhesion (52%), crazy-paving pattern (50%), consolidation (48%), fibrosis (32%), discrete nodules (8%), bronchiectasis (6%), thoracic lymphadenopathy (4%), pleural effusion (4%), and cavitation (2%) (Table 2). There was no significant difference in the occurrence rate of all ten CT characteristics in the initial CT between the two groups (all p >0.05). However, there were differences in the occurrence rate of ground-glass opacity (50% vs. 82%, p=0.040) and crazy-paving pattern (75% vs. 39%, p=0.031) in the second follow-up CT, and pleural thickening or adhesion (100% vs. 65%, p=0.019) in the third follow-up CT between the severe and critical group and the moderate group (Table 4). There were no differences in the occurrence rate of consolidation and fibrosis in every follow-up CT between the two groups (all p >0.05, Table 4).
Table 4. The findings of top five CT characteristics in the CT follow-up between two groups
CT follow-up
|
ground glass opacity
|
consolidation
|
crazy-paving pattern
|
pleural thickening or adhesion
|
fibrosis
|
First follow-up CT
|
|
|
|
|
|
Moderate type (n=34)
|
31 (91%)
|
20 (59%)
|
15 (44%)
|
22 (65%)
|
17 (50%)
|
Severe and critical type (n=16)
|
13 (81%)
|
11 (69%)
|
11 (69%)
|
12 (75%)
|
7 (44%)
|
p value
|
0.370
|
0.549
|
0.135
|
0.533
|
0.767
|
Second follow-up CT
|
|
|
|
|
|
Moderate type (n=28)
|
23 (82%)
|
22 (79%)
|
11 (39%)
|
22 (79%)
|
15 (54%)
|
Severe and critical type (n=16)
|
8 (50%)
|
13 (81%)
|
12 (75%)
|
16 (100%)
|
8 (50%)
|
p value
|
0.040*
|
1.000
|
0.031*
|
0.072
|
1.000
|
Third follow-up CT
|
|
|
|
|
|
Moderate type (n=17)
|
12 (71%)
|
8 (47%)
|
6 (35%)
|
11 (65%)
|
9 (53%)
|
Severe and critical type (n=15)
|
10 (67%)
|
11 (73%)
|
10 (67%)
|
15 (100%)
|
10 (67%)
|
p value
|
1.000
|
0.166
|
0.156
|
0.019*
|
0.491
|
Fourth follow-up CT
|
|
|
|
|
|
Moderate type (n=8)
|
7 (88%)
|
1 (13%)
|
2 (25%)
|
6 (75%)
|
4 (50%)
|
Severe and critical type (n=15)
|
10 (67%)
|
7 (47%)
|
7 (47%)
|
14 (93%)
|
11 (73%)
|
p value
|
0.369
|
0.176
|
0.400
|
0.269
|
0.371
|
Fifth follow-up CT
|
|
|
|
|
|
Severe and critical type (n=8)
|
3 (38%)
|
4 (50%)
|
4 (50%)
|
7 (88%)
|
5 (63%)
|
Sixth follow-up CT
|
|
|
|
|
|
Severe and critical type (n=5)
|
5 (100%)
|
0 (0%)
|
0 (0%)
|
3 (60%)
|
3 (60%)
|
Seventh follow-up CT
|
|
|
|
|
|
Severe and critical type (n=3)
|
3 (100%)
|
0 (0%)
|
0 (0%)
|
3 (100%)
|
1 (33%)
|
* p<0.05
In the severe and critical group, the GGO, fibrosis, and pleural thickening or adhesion could be found in every follow-up CT and were the main signs in the last two CT follow-up (figure 2). The proportions of patients with the crazy-paving pattern (75%) and consolidation (81%) reached a peak with the decrease in the proportion of GGO (50%) at the second follow-up CT. The occurrence rate of pleural thickening or adhesion (100% and 100%) peaked at the second and the third follow-up CT.
In the moderate group, the proportions of patients with GGO and the crazy-paving pattern gradually decreased from the initial CT. The proportions of patients with the consolidation (79%) and pleural thickening or adhesion (79%) reached the peak with the decrease in the proportion of crazy-paving pattern (39%) at the second follow-up CT. Both in the third and fourth follow-up CT, the GGO and pleural thickening or adhesion the main demonstration with the obvious absorption of consolidation and crazy-paving pattern, and fibrosis was still present.