LitCovid-sentences  

PMC:7095437 / 1955-29129 JSONTXT 15 Projects

Annnotations TAB TSV DIC JSON TextAE

Id Subject Object Predicate Lexical cue
T21 0-12 Sentence denotes Introduction
T22 13-272 Sentence denotes Since December 2019, an increasing number of pneumonia cases caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, Hubei, China, and subsequently, an outbreak of coronavirus disease 2019 (COVID-19) swept the globe [1–4].
T23 273-437 Sentence denotes As of February 3, 2020, more than 23,214 suspected cases and 20,438 confirmed cases have been identified, and there has been over 425 deaths related to the illness.
T24 438-497 Sentence denotes Moreover, the virus is still spreading at an alarming rate.
T25 498-615 Sentence denotes In this sudden epidemic, reverse transcription polymerase chain reaction (RT-PCR) revealed the cause of the outbreak.
T26 616-711 Sentence denotes The SARS-CoV-2 can be specifically detected in respiratory secretions or plasma samples RT-PCR.
T27 712-940 Sentence denotes However, some patients with likely COVID-19 may have negative initial RT-PCR results for COVID-19, which may be due to insufficient cellular material for detection or improper extraction of nucleic acids from clinical materials.
T28 941-1239 Sentence denotes Thus, imaging examination, which can effectively and conveniently observe the pulmonary parenchymal abnormalities, can solve some challenges associated with clinical diagnosis in suspected patients with a false-negative result, especially symptomatic patients with dyspnea and respiratory distress.
T29 1240-1363 Sentence denotes Because this infection is caused by the unprecedented SARS-CoV-2, few related imaging studies have been currently reported.
T30 1364-1510 Sentence denotes Among the studies that have been conducted, multifocal consolidation or ground-glass opacity (GGO) was observed on chest radiographs and CT [5–7].
T31 1511-1890 Sentence denotes However, the sensitivity of chest radiographs for pneumonia are relatively low, and it is difficult to use chest radiographs to distinguish COVID-19 from common pneumonia during the cold season and pneumonia caused by other coronaviruses, such as severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) infections [8].
T32 1891-1976 Sentence denotes In addition, the disease is developing rapidly and the symptoms of this disease vary.
T33 1977-2244 Sentence denotes Hence, it is very necessary to systematically analyze the chest CT findings associated with this disease systematically, for the timely isolation, COVID-19 RT-PCR and respiratory care of patients, and early implementation of infection prevention and control measures.
T34 2245-2518 Sentence denotes To fully understand and early discriminate the CT features of this disease in its early stages, we collected initial chest CT data from confirmed COVID-19 patients who did not receive any antiviral treatment mainly from Chongqing Three Gorges Central Hospital for analysis.
T35 2519-2802 Sentence denotes The Chongqing Three Gorges Central Hospital, located in the northeast of Chongqing and connected to Hubei Province, is one of the designated hospitals for the centralized treatment of pneumonia patients infected by the SARS-CoV-2 and has received a large number of COVID-19 patients.
T36 2803-3037 Sentence denotes Therefore, our aim was to systematically analyze the CT features of the early and progressive stages of the natural course of COVID-19 and explore the possible pathological changes in the lung during different periods of this disease.
T37 3039-3060 Sentence denotes Materials and methods
T38 3062-3080 Sentence denotes Study participants
T39 3081-3320 Sentence denotes This retrospective study was approved by the Institutional Ethics Committee of Chongqing Three Gorges Central Hospital and the Second Affiliated Hospital of Chongqing Medical University, and the requirement for informed consent was waived.
T40 3321-3565 Sentence denotes Between January 21 and February 4, 2020, totally 72 patients of confirmed COVID-19 were enrolled, i.e., 66 patients from Chongqing Three Gorges Central Hospital and 6 patients from the Second Affiliated Hospital of Chongqing Medical University.
T41 3566-3787 Sentence denotes All patients with COVID-19 were diagnosed according to the World Health Organization (WHO) interim guidance [9] and were eventually confirmed by a positive result for RT-PCR analysis of the respiratory secretions samples.
T42 3788-3958 Sentence denotes Confirmed patients were eligible if they experienced symptoms within 7 days, underwent an initial chest CT examination, and they had not received any antiviral treatment.
T43 3959-4208 Sentence denotes The exclusion criteria were as follows: (1) patients who recently experienced clinically defined pulmonary infection attributable to other pathogens, (2) patients with severe artifacts on CT images, and (3) patients whose age was less than 18 years.
T44 4209-4378 Sentence denotes According to the exclusion criteria, 7 patients who had pulmonary infections caused by other pathogens and 3 patients whose CT images had severe artifacts were excluded.
T45 4379-4536 Sentence denotes Finally, 62 confirmed COVID-19 patients (34 men, 28 women; age range 20–91 years old) who had not received antiviral treatment were retrospectively reviewed.
T46 4537-4600 Sentence denotes The workflow of COVID-19 patients selection is shown in Fig. 1.
T47 4601-4725 Sentence denotes Most cases had a history of SARS-CoV-2 exposure, in the absence of medical staff or family clusters of SARS-CoV-2 infection.
T48 4726-4861 Sentence denotes The main symptom of patients was fever, and secondary symptoms included cough, expectoration, dizziness, nasal congestion, and myalgia.
T49 4862-5200 Sentence denotes According to the changes in this disease over time [10, 11], in our study, we defined patients with an onset of symptoms within 4 days as the early-stage group (18 men, 16 women; age range 20–72 years old) and patients with an onset of symptoms within 5–7 days as the progressive-stage group (16 men, 12 women; age range 22–91 years old).
T50 5201-5422 Sentence denotes All patients underwent CT scans and laboratory examinations for C-reactive protein (CRP), white blood cell count, neutrophil count, lymphocyte count, platelet count, hemoglobin level, and procalcitonin level on admission.
T51 5423-5480 Sentence denotes Fig. 1 The workflow of coronavirus disease 2019 selection
T52 5482-5501 Sentence denotes CT data acquisition
T53 5502-5699 Sentence denotes Designated independent operating rooms were used to perform the CT examinations of all confirmed patients and after each examination; the operating room was sterilized with air disinfection method.
T54 5700-6040 Sentence denotes The initial chest CT data of 56 patients from Chongqing Three Gorges Central Hospital were obtained by using a 16-slice spiral CT scanner (Emotion 16 VC20B, Siemens Healthcare GmbH) with the following scanning protocol: a tube voltage of 120 kV, smart mA tube current modulation, a slice thickness of 1.5 mm, and a detector width of 1.5 mm.
T55 6041-6429 Sentence denotes The initial chest CT data of the other 6 patients from the Second Affiliated Hospital of Chongqing Medical University were obtained by using a 128-slice spiral CT scanner (Ingenuity CT, Philips Healthcare) with a similar scanning protocol: a tube voltage of 120 kV, smart mA tube current modulation, a matrix size of 512 × 512, a slice thickness of 1 mm, and a detector width of 0.625 mm.
T56 6430-6589 Sentence denotes All patients were scanned in the supine position and at the suspended end-inspiratory volume, and the entire lung was scanned from the apex to the bottom [12].
T57 6590-6762 Sentence denotes To reduce discrepancies in the image acquisition parameters attributable to the different CT scanners, we resampled all voxels at 1.0 × 1.0 × 1.0 mm3 before image analysis.
T58 6763-6894 Sentence denotes The multiplanar reconstruction (MPR) technique was performed to better observe images at the postprocessing station when necessary.
T59 6896-6912 Sentence denotes CT data analysis
T60 6913-7468 Sentence denotes All CT findings were described according to the Fleischner Society recommendations and defined as follows: GGO (appears as hazy increased opacity in the lung, with the preservation of bronchial and vascular margins), consolidation (appears as a homogeneous increase in pulmonary parenchymal attenuation that obscures the margins of vessels and airway walls), a crazy-paving pattern (appears as thickened interlobular septa and intralobular lines superimposed on a background of GGO), and a halo sign (appears as GGO surrounding a nodule or mass) [13, 14].
T61 7469-7849 Sentence denotes Attention was paid to CT images with GGO, consolidation, GGO with consolidation, a reticular pattern, nodules, rounded opacities, cavitation, a crazy-paving pattern, an air bronchogram, a halo sign, bronchial wall thickening, a subpleural curvilinear line, and pulmonary fibrosis, and the presence, distribution, and size of these CT characteristics were assessed in all subjects.
T62 7850-8038 Sentence denotes In addition, the presence of thoracic lymphadenopathy (lymph node size of greater than or equal to 10 mm in the short-axis dimension) and pleural effusion or thickening were also recorded.
T63 8039-8276 Sentence denotes The distribution of each finding was classified as follows: central (predominantly in the inner two-thirds of the lung), peripheral (predominantly in the outer third of the lung), and diffuse (indications in multiple lung segments) [15].
T64 8277-8430 Sentence denotes Calculation of the CT score, a semiquantitative evaluation method, was applied to quantify the extent of COVID-19 according to previous studies [15, 16].
T65 8431-8712 Sentence denotes First, the scope of the lesions in each lobe was estimated and a score of 0 (none), 1 (affecting less than 5% of the lobe), 2 (affecting 5–25% of the lobe), 3 (affecting 26–49% of the lobe), 4 (affecting 50–75% of the lobe), or 5 (affecting more than 75% of the lobe) was assigned.
T66 8713-8789 Sentence denotes Second, the CT score was obtained by adding up the scores of the five lobes.
T67 8790-8849 Sentence denotes For each patient, the CT score was in the range of 0 to 25.
T68 8850-9016 Sentence denotes All CT scans were independently reviewed and assessed by two chest radiologists (Z.F. and L.L.C., who had 18 years of experience in thoracic radiology, respectively).
T69 9017-9092 Sentence denotes Disagreements in reader interpretation were settled by consensus agreement.
T70 9094-9114 Sentence denotes Statistical analysis
T71 9115-9229 Sentence denotes All of the data were analyzed with statistical software (SPSS statistical package, version 19.0; IBM Corporation).
T72 9230-9402 Sentence denotes Continuous variables were expressed as means ± standard deviations or median (interquartile range (IQR)), and categorical variables were presented as numbers (percentages).
T73 9403-9477 Sentence denotes Kolmogorov-Smirnov tests were applied to check the normality of variables.
T74 9478-9543 Sentence denotes Mann-Whitney U tests were used for non-normally distributed data.
T75 9544-9603 Sentence denotes Two-sample t tests were used for normally distributed data.
T76 9604-9691 Sentence denotes Chi-square tests or Fisher’s exact tests were applied to compare categorical variables.
T77 9692-9984 Sentence denotes Spearman’s correlation was performed to analyze the relationship between clinical variables (age, fever, CRP, white blood cell count, neutrophil count, lymphocyte count, platelet count, hemoglobin level, and procalcitonin level) and CT variables (maximum diameter of the lesion and CT score).
T78 9985-10076 Sentence denotes For all test results, a p value of less than 0.05 was considered statistically significant.
T79 10078-10085 Sentence denotes Results
T80 10087-10153 Sentence denotes Demographic and clinical characteristics of patients with COVID-19
T81 10154-10255 Sentence denotes The demographic and clinical characteristics of all patients with COVID-19 are summarized in Table 1.
T82 10256-10413 Sentence denotes Among all 62 patients, 51 (82.3%) patients had a confirmed history of SARS-CoV-2 exposure, 43 (69.4%) patients had fever, and mainly low-grade fever (46.8%).
T83 10414-10696 Sentence denotes There were no significant differences in terms of age, sex, and laboratory test results (CRP, white blood cell count, neutrophil count, lymphocyte count, platelet count, hemoglobin level, procalcitonin level) between the early-stage group and progressive-stage group (all p > 0.05).
T84 10697-10790 Sentence denotes Table 1 Demographic and clinical characteristics between two groups in patients with COVID-19
T85 10791-10868 Sentence denotes Variables Early-stage group (n = 34) Progressive-stage group (n = 28) p value
T86 10869-10880 Sentence denotes Demographic
T87 10881-10929 Sentence denotes   Age, (years) 44.32 ± 13.53 50.82 ± 13.23 0.062
T88 10930-10968 Sentence denotes   Male 18 (52.9%) 16 (57.1%) 0.741 (χ)
T89 10969-10995 Sentence denotes Exposure history 0.494 (χ)
T90 10996-11028 Sentence denotes   Positive 27 (79.4%) 24 (85.7%)
T91 11029-11058 Sentence denotes   Negative 4 (11.8%) 1 (3.6%)
T92 11059-11087 Sentence denotes   Unknown 3 (8.8%) 3 (10.7%)
T93 11088-11096 Sentence denotes Symptoms
T94 11097-11141 Sentence denotes   Fever (°C) 37.70 ± 0.73 37.66 ± 0.94 0.854
T95 11142-11184 Sentence denotes   < 37.4 °C 8 (23.5%) 11 (39.3%) 0.064 (χ)
T96 11185-11218 Sentence denotes   37.4–38 °C 20 (58.8%) 9 (32.1%)
T97 11219-11251 Sentence denotes   38.1–39 °C 4 (11.8%) 6 (21.4%)
T98 11252-11282 Sentence denotes   39.1–41 °C 2 (5.9%) 2 (7.1%)
T99 11283-11299 Sentence denotes Laboratory tests
T100 11300-11356 Sentence denotes   CRP (mg/L) 15.98 (1.78–55.98) 35.62 (5.63–63.04) 0.329
T101 11357-11421 Sentence denotes   White blood cell count (× 109/L) 5.78 ± 1.93 6.24 ± 3.55 0.518
T102 11422-11480 Sentence denotes   Neutrophil count (× 109/L) 0.71 ± 0.13 0.74 ± 0.11 0.343
T103 11481-11539 Sentence denotes   Lymphocyte count (× 109/L) 1.04 ± 0.49 0.97 ± 0.46 0.541
T104 11540-11602 Sentence denotes   Platelet count (× 109/L) 180.79 ± 66.83 190.18 ± 73.91 0.602
T105 11603-11654 Sentence denotes   Hemoglobin (g/dL) 13.72 ± 1.79 13.69 ± 1.80 0.956
T106 11655-11718 Sentence denotes   Procalcitonin (ng/mL) 0.05 (0.04–0.07) 0.07 (0.04–0.11) 0.234
T107 11719-11778 Sentence denotes COVID-19, coronavirus disease 2019; CRP, C-reactive protein
T108 11780-11817 Sentence denotes CT findings in patients with COVID-19
T109 11818-11948 Sentence denotes The CT findings of patients with COVID-19 in early and progressive stages are listed in Table 2 and shown in Figs. 2, 3, 4, and 5.
T110 11949-12044 Sentence denotes In terms of CT characteristics, the major finding was the GGO in 38 (61.3%) of the 62 patients.
T111 12045-12571 Sentence denotes In addition, GGO with consolidation was observed in 22 (35.5%) patients; rounded opacities were observed in 16 (25.8%) patients; a crazy-paving pattern was observed in 16 (25.8%) patients; an air bronchogram was observed in 14 (22.6%) patients; a halo sign was observed in 7 (11.3%) patients; a subpleural curvilinear line was observed in 6 (9.7%) patients; pleural effusion was observed in 2 (3.2%) patients; and consolidation, nodules, thoracic lymphadenopathy, and pulmonary fibrosis were observed in 1 (1.6%) patient each.
T112 12572-12655 Sentence denotes No patient presented cavitation, a reticular pattern, or bronchial wall thickening.
T113 12656-12807 Sentence denotes Between the early-stage group and progress-stage group, there were no significant differences in the CT findings, except for the halo sign (p = 0.013).
T114 12808-12901 Sentence denotes Specifically, the halo sign was found in only the early-stage group in 20.6% of the patients.
T115 12902-12991 Sentence denotes Table 2 Comparison of CT findings and scores between two groups in patients with COVID-19
T116 12992-13069 Sentence denotes Variables Early-stage group (n = 34) Progressive-stage group (n = 28) p value
T117 13070-13081 Sentence denotes CT findings
T118 13082-13136 Sentence denotes   Ground-glass opacity 22 (64.7%) 16 (57.1%) 0.543 (χ)
T119 13137-13178 Sentence denotes   Consolidation 1 (2.9%) 0 (0%) 1.000 (χ)
T120 13179-13252 Sentence denotes   Ground-glass opacity with consolidation 11 (32.4%) 11 (39.3%) 0.570 (χ)
T121 13253-13278 Sentence denotes   Reticular pattern 0 0 –
T122 13279-13308 Sentence denotes   Nodule 1 (2.9%) 0 1.000 (χ)
T123 13309-13359 Sentence denotes   Rounded opacities 10 (29.4%) 6 (21.4%) 0.475 (χ)
T124 13360-13378 Sentence denotes   Cavitation 0 0 –
T125 13379-13431 Sentence denotes   Crazy-paving pattern 8 (23.5%) 8 (28.6%) 0.652 (χ)
T126 13432-13479 Sentence denotes   Air bronchogram 8 (23.5%) 6 (21.4%) 0.844 (χ)
T127 13480-13513 Sentence denotes   Halo sign 7 (20.6%) 0 0.013 (χ)
T128 13514-13547 Sentence denotes   Bronchial wall thickening 0 0 –
T129 13548-13606 Sentence denotes   Subpleural curvilinear line 4 (11.8%) 2 (7.1%) 0.681 (χ)
T130 13607-13654 Sentence denotes   Thoracic lymphadenopathy 0 1 (3.6%) 0.452 (χ)
T131 13655-13715 Sentence denotes   Pleural effusion or thickening 1 (2.9%) 1 (3.6%) 1.000 (χ)
T132 13716-13757 Sentence denotes   Pulmonary fibrosis 0 1 (3.6%) 0.452 (χ)
T133 13758-13817 Sentence denotes   Max diameter of lesion (cm) 4.27 ± 2.66 5.83 ± 3.76 0.059
T134 13818-13848 Sentence denotes     < 1 cm 0 1 (3.6) 0.201 (χ)
T135 13849-13882 Sentence denotes     1–2.9 cm 13 (38.2%) 5 (17.9%)
T136 13883-13917 Sentence denotes     3–4.9 cm 12 (35.3%) 10 (35.7%)
T137 13918-13949 Sentence denotes     > 5 cm 9 (26.5%) 12 (42.9%)
T138 13950-13962 Sentence denotes Distribution
T139 13963-14000 Sentence denotes   Central 1 (2.9%) 1 (3.6%) 0.961 (χ)
T140 14001-14034 Sentence denotes   Peripheral 12 (35.3%) 9 (32.1%)
T141 14035-14086 Sentence denotes   Both central and peripheral 21 (61.8%) 18 (64.3%)
T142 14087-14125 Sentence denotes CT score 4.79 ± 2.76 7.79 ± 4.62 0.004
T143 14126-14163 Sentence denotes   0–5 27 (79.4%) 10 (35.7%) 0.004 (χ)
T144 14164-14191 Sentence denotes   6–10 6 (17.6%) 12 (42.9%)
T145 14192-14211 Sentence denotes   11–15 0 3 (10.7%)
T146 14212-14237 Sentence denotes   > 15 1 (2.9%) 3 (10.7%)
T147 14238-14272 Sentence denotes COVID-19, coronavirus disease 2019
T148 14273-14569 Sentence denotes Fig. 2 A 56-year-old male with coronavirus disease 2019 in the early-stage group. a Axial non-contrast CT shows ground-glass opacities in the anterior segments of bilateral upper lobes. b Ground-glass opacity is also shown in the peripheral region of the lateral basal segment of left lower lobe.
T149 14570-14649 Sentence denotes CT score = 1 (right upper lobe) + 1 (left upper lobe) + 1 (left lower lobe) = 3
T150 14650-15070 Sentence denotes Fig. 3 A 34-year-old female with coronavirus disease 2019 in the early-stage group. a Axial non-contrast CT shows halo sign in the dorsal segment of left lower lobe and multiple ground-glass opacities in the right upper lobe and the dorsal segment of the right lower lobe. b Sagittal non-contrast CT demonstrates multiple ground-glass opacities with consolidations in the right lung, mainly distributed in the periphery.
T151 15071-15151 Sentence denotes CT score = 2 (right upper lobe) + 2 (right lower lobe) + 1 (left lower lobe) = 5
T152 15152-15516 Sentence denotes Fig. 4 A 40-year-old female with coronavirus disease 2019 in the progressive-stage group. a Axial non-contrast CT shows crazy-paving pattern in the anterior segment and consolidation in the posterior segment of right upper lobe. b Consolidations are noted in the bilateral lower lobes mainly in the peripheral regions, accompanied with subpleural curvilinear line.
T153 15517-15644 Sentence denotes CT score = 3 (right upper lobe) + 1 (right middle lobe) + 3 (right lower lobe) + 1 (left upper lobe) + 3 (left lower lobe) = 11
T154 15645-15973 Sentence denotes Fig. 5 A 60-year-old male with coronavirus disease 2019 in the progressive-stage group. a Axial non-contrast CT in pulmonary window shows diffuse ground-glass opacities with consolidations in bilateral lungs. b Axial non-contrast CT in mediastinal window shows consolidations in bilateral lungs, with bilateral pleural effusion.
T155 15974-16101 Sentence denotes CT score = 5 (right upper lobe) + 4 (right middle lobe) + 4 (right lower lobe) + 3 (left upper lobe) + 2 (left lower lobe) = 18
T156 16102-16458 Sentence denotes In terms of lesion size, lesions with a maximum diameter greater than 5 cm were found in 21 (33.9%) of 62 patients; lesions with a maximum diameter of 3–4.9 cm were found in 22 (35.5%) patients; lesions with a maximum diameter of 1–2.9 cm were found in 18 (29.0%) patients; and lesions with a maximum diameter less than 1 cm were found in 1 (1.6%) patient.
T157 16459-16585 Sentence denotes There was no statistically significant difference in lesion size between the two groups of patients with COVID-19 (p = 0.059).
T158 16586-16917 Sentence denotes Regarding the distribution of pulmonary parenchymal abnormalities, lesions that were mainly distributed in both the central and peripheral lung regions accounted for 62.9%; lesions distributed in the peripheral lung were present in 21 (33.9%) patients; and lesions distributed in the central lung were present in 2 (3.2%) patients.
T159 16918-17088 Sentence denotes There was no statistically significant difference in the distribution of pulmonary parenchymal abnormalities between the two groups of patients with COVID-19 (p = 0.961).
T160 17090-17124 Sentence denotes CT score of patients with COVID-19
T161 17125-17259 Sentence denotes The CT scores of all patients with COVID-19 are shown in Table 2 and the CT scores of each lobe in the two groups are shown in Fig. 6.
T162 17260-17380 Sentence denotes The CT scores of the progressive-stage group were significantly greater than those of the early-stage group (p = 0.004).
T163 17381-17552 Sentence denotes In the early-stage group, 27 (79.4%) patients had CT scores in the range of 0–5, 6 (17.6%) patients had CT scores of 6–10, and only 1 patient had a CT score of 11 or more.
T164 17553-17777 Sentence denotes In the progressive-stage group, 10 (35.7%) patients had CT scores in the range of 0–5, 12 (42.9%) patients had CT scores of 6–10, 3 (10.7%) patients had CT scores of 11–15, and 3 (10.7%) patients had CT scores of 15 or more.
T165 17778-17863 Sentence denotes Fig. 6 The CT score of each lobe in the early-stage group and progressive-stage group
T166 17864-18185 Sentence denotes Among all 62 COVID-19 patients, the CT scores of pulmonary parenchymal abnormalities were significantly positively correlated with maximum diameter of the lesions (r = 0.531, p < 0.001), and the CT scores were also significantly positively correlated with the age of the patients (r = 0.255, p = 0.045), shown in Table 3.
T167 18186-18267 Sentence denotes Table 3 Correlation of clinical variables with CT score in patients with COVID-19
T168 18268-18286 Sentence denotes Variables CT score
T169 18287-18298 Sentence denotes Age (years)
T170 18299-18314 Sentence denotes   p value 0.045
T171 18315-18330 Sentence denotes   r value 0.255
T172 18331-18358 Sentence denotes Max diameter of lesion (cm)
T173 18359-18376 Sentence denotes   p value < 0.001
T174 18377-18392 Sentence denotes   r value 0.531
T175 18393-18427 Sentence denotes COVID-19, coronavirus disease 2019
T176 18429-18439 Sentence denotes Discussion
T177 18440-18558 Sentence denotes As reported, patients with COVID-19 usually develop clinical symptoms after an incubation period of 4.1–7.0 days [11].
T178 18559-18624 Sentence denotes After admission, chest imaging examination was performed on them.
T179 18625-18993 Sentence denotes According to the results of changes in this disease in recent studies [10, 11], the patient’s condition progressively worsens on the 3–5 days after symptom onset, and the guidelines for an imaging diagnosis of COVID-19 recommend that reviewing CT or plain radiograph is needed for suspected cases 3–5 days after diagnosis to observe changes in the disease status [12].
T180 18994-19154 Sentence denotes Thus, we assigned patients to two groups according to the time of onset of symptoms to analyze the CT findings in early-stage and progressive-stage of COVID-19.
T181 19155-19312 Sentence denotes In this study, 62 confirmed patients with COVID-19 underwent chest CT scans, and positive rate of detecting the pulmonary parenchymal abnormalities was 100%.
T182 19313-19697 Sentence denotes In addition, the CT data in our study were obtained from the initial chest CT examination of patients who had not received any antiviral therapy; these results may better reflect the degree of viral infection and the immune system status before clinical intervention and provide an important basis for clinical classification, treatment strategy development, and prognosis prediction.
T183 19698-19898 Sentence denotes In our study, the major characteristic of COVID-19 was GGO (61.3%), followed by GGO with consolidation (35.5%), rounded opacity (25.8%), a crazy-paving pattern (25.8%), and an air bronchogram (22.6%).
T184 19899-19996 Sentence denotes In contrast, pulmonary fibrosis (1.6%) and pleural effusions (3.2%) were rare on chest CT images.
T185 19997-20117 Sentence denotes These various CT findings are likely related to the complex pathological changes in the lungs of patients with COVID-19.
T186 20118-20479 Sentence denotes Although pathological changes in the lung tissue of COVID-19 patients have not yet been studied, recent studies have reported that SARS-CoV-2 is closely related (with 88% identity) to two bat-derived severe acute respiratory syndrome (SARS)–like coronaviruses, with approximately 79% homology with SARS-CoV and approximately 50% homology with MERS-CoV [17, 18].
T187 20480-20709 Sentence denotes Because the pathogenesis of viral infections in the same family may be similar, previous studies on coronaviruses may be helpful in understanding the various CT findings in COVID-19 patients based on similar pathological changes.
T188 20710-20998 Sentence denotes In SARS patients, pathological changes include injury to pulmonary epithelial cells, hyaline membrane formation on in the inner wall of the alveoli, and a large number of tissue cells and mass thrombi formed by proliferative fibrous tissue that block the small airway and air cavity [19].
T189 20999-21100 Sentence denotes These pathological changes may be the main pathological basis of the CT findings, especially the GGO.
T190 21101-21308 Sentence denotes Among all the CT findings, GGO was the most common one in both the early and progressive stages of COVID-19 and was characterized by multiple sized lesions, mainly distributed in the peripheral lung (96.8%).
T191 21309-21619 Sentence denotes An analysis of thin-section CT images of SARS patients showed that multiple GGOs were the main imaging finding (68.4%) and were distributed in the periphery of the lung (71.8%), with interlobular septal thickening (24.2%) and intralobular interstitial hyperplasia (32.2%), also called the crazy-paving pattern.
T192 21620-21694 Sentence denotes These findings are very similar to the CT manifestations of COVID-19 [20].
T193 21695-21850 Sentence denotes For pneumonia caused by MERS-CoV, GGO was also found on the chest CT images and was mainly distributed in the subpleural and basilar lung regions [21, 22].
T194 21851-22010 Sentence denotes Interestingly, pleural effusion was rare and no tree-in-bud pattern or cavitation was found in pneumonia patients infected by the three kinds of coronaviruses.
T195 22011-22110 Sentence denotes In addition, we found that only one case of COVID-19 (1.6%) presented as consolidation without GGO.
T196 22111-22289 Sentence denotes Compared with the large amount of consolidation that appears in the early stage of SARS, we speculate that the pathogenicity of SARS-CoV-2 may be less than that of SARS-CoV [23].
T197 22290-22529 Sentence denotes Thus, it is necessary to fully understand and discriminate the CT features of COVID-19 at an early stage, which is helpful for the timely isolation and respiratory care of patients and early implementation of infection prevention measures.
T198 22530-22726 Sentence denotes In addition to GGO, another important CT characteristic of COVID-19 was multiple GGOs with consolidations, accompanied by interlobular septal thickening, mainly in the peripheral part of the lung.
T199 22727-22939 Sentence denotes These basic CT features were similar to the findings reported by Huang et al, whose study showed that multiple GGOs with partial consolidation appeared bilaterally on the chest CT images of COVID-19 patients [7].
T200 22940-23113 Sentence denotes Similarly, in another chest CT study of a 33-year-old patient diagnosed with COVID-19 in Wuhan, China, multiple GGOs distributed in both the peripheral lungs were found [5].
T201 23114-23302 Sentence denotes Therefore, we suggest that multiple GGOs with consolidations mainly in the periphery of the lung are a basic CT feature of COVID-19, which is helpful for the initial screening of COVID-19.
T202 23303-23450 Sentence denotes Unexpectedly, the halo sign (20.6%) was the only significantly different CT manifestation in the early stage of COVID-19 among all the CT findings.
T203 23451-23524 Sentence denotes In our study, the halo sign appeared in only the early stage of COVID-19.
T204 23525-23696 Sentence denotes We hypothesized that the halo sign rapidly changed into GGO within 1 week due to the aggravation of COVID-19, and no other new halo sign had been formed in the short term.
T205 23697-23823 Sentence denotes In addition, there were no significant differences in the other CT findings or distribution of lesions between the two stages.
T206 23824-24159 Sentence denotes For these findings, we speculated that the speed of GGO formation was due to the damage to the alveolar epithelium caused by the virus and may be similar to that of consolidation caused by an inflammatory reaction of the lung tissue, resulting in a change in different types of lesions during the synchronous increase in opacification.
T207 24160-24394 Sentence denotes In pneumonia caused by SARS-CoV, Ooi et al found that GGO and consolidation formed in the first week of SARS-CoV infection increased in the second week, and only residual strips and reticular shadows were seen in the fourth week [15].
T208 24395-24526 Sentence denotes Therefore, the CT manifestations of COVID-19 are different at different stages, which helps the differential diagnosis of COVID-19.
T209 24527-24672 Sentence denotes Furthermore, our results showed that the CT scores in the progressive-stage group were significantly greater than those in the early-stage group.
T210 24673-24953 Sentence denotes Further analysis showed that the CT scores were positively correlated with the maximum diameters of the lesions (r = 0.531), indicating that the range of lesions in the progressive stage was larger than and the degree of inflammation was more serious than that in the early stage.
T211 24954-25117 Sentence denotes These results also showed that without any antiviral treatment, COVID-19 continued to progress 5–7 days after the onset of symptoms, without any improvement trend.
T212 25118-25260 Sentence denotes Therefore, necessary clinical measures, including antiviral and supportive therapies, should be administered to prevent disease deterioration.
T213 25261-25416 Sentence denotes Because of the lack of additional data, the correlation between the CT score and clinical classification and the prognosis of COVID-19 needs further study.
T214 25417-25520 Sentence denotes Moreover, CT scores showed a significant positive correlation with ages in all 62 patients (r = 0.255).
T215 25521-25658 Sentence denotes In a previous study on SARS, Grinblat et al considered that age was a risk factor for severe lung injury and poor prognosis of SARS [24].
T216 25659-25754 Sentence denotes Therefore, elderly patients need to be treated earlier and more actively than younger patients.
T217 25755-25789 Sentence denotes Our study had several limitations.
T218 25790-25948 Sentence denotes First, because COVID-19 is a novel disease and lacks a series and long-term CT data, we can analyze only the existing information in a retrospective analysis.
T219 25949-26133 Sentence denotes Moreover, the time of chest CT examination after symptom onset was inconsistent, so it was difficult to summarize the CT appearances that could reflect the whole course of the disease.
T220 26134-26268 Sentence denotes Second, the sample size in our study was relatively small, and there may be deviation in the comparison of the results of CT findings.
T221 26269-26344 Sentence denotes Third, most of our cases were imported cases and some were secondary cases.
T222 26345-26514 Sentence denotes Further research is needed to observe whether virus variation exists in the process of infection and whether virus variation will produce different in CT manifestations.
T223 26515-26587 Sentence denotes Finally, there was no histopathological evidence from deceased patients.
T224 26588-26748 Sentence denotes In conclusion, our study showed that chest CT examination was very effective in detecting pulmonary parenchymal abnormalities in the natural course of COVID-19.
T225 26749-26852 Sentence denotes Multiple GGOs with consolidations in the peripheral lung was the primary CT characteristic of COVID-19.
T226 26853-27034 Sentence denotes The halo sign may be a special CT feature in the early stage of COVID-19, while a significantly increased CT score may indicate the aggravation of COVID-19 in the progressive stage.
T227 27035-27174 Sentence denotes In patients with dyspnea and respiratory distress, CT examination is very effective in the preclinical screening of patients with COVID-19.