Predictive value of biphasic CT air trapping sign and semi-quantitative score in predicting abnormal blood gas index and progression to severe disease in COVID-19 patients
10.3760/cma.j.cn112149-20210226-00159
- VernacularTitle:双相CT空气潴留征与半定量评分预测新型冠状病毒肺炎患者血气指标异常及进展为重症的价值
- Author:
Lijuan ZHOU
1
;
Xiaoming LIN
;
Haixia MAO
;
Yaxing BAO
;
Shiliang ZHANG
;
Hongwei CHEN
;
Quansheng GAO
;
Lan GU
;
Xiangming FANG
Author Information
1. 南京医科大学附属无锡人民医院影像科，无锡 214023
- Keywords:
Tomography,X-ray computed;
COVID-19;
Air trapping sign;
Semi-quantitative
- From:
Chinese Journal of Radiology
2022;56(3):241-247
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To explore the predictive value of low-dose biphasic (inspiratory and expiratory) CT air trapping sign and semi-quantitative score in predicting abnormal blood gas parameters and progression to severe disease in COVID-19 patients.Methods:Patients with non-severe COVID-19 who were diagnosed by nucleic acid testing and hospitalized in designated hospitals in Wuxi City from January 23 to February 29, 2020 were prospectively and consecutively recruited. All patients received low-dose biphasic CT examination on admission and repeated CT examination at regular intervals during the course. On the inspiratory phase admission of the bipolar CT, the scope of the lesion was evaluated by semi-quantitative score, and the air trapping sign on bipolar CT was assessed. The differences of semi-quantitative score, the presence of the air trapping sign and other clinical factors were compared between the patients with abnormal and the normal blood gas index, as well as between the cases progressed to severe disease and cases without disease progression using the independent sample t-test or χ 2 test. The area under the curve (AUC) of receiver operating characteristic (ROC) and the comprehensive discriminant improvement index (IDI) were used to evaluate the predictive effectiveness of the semi-quantitative scores, air trapping sign, and combination of two factors in differentiating cases with abnormal and normal blood gas indexes, as well as in differentiating cases with and without disease progression to severe COVID-19 cases. Results:In total 51 non-severe COVID-19 cases were included, with 16 cases showed air trapping sign during the first biphasic CT examination on admission. During the course of the disease, there were 13 patients with abnormal blood gas index, and 9 cases displaying air trapping sign (9/13). All 7 cases with progression to severe cases showed air trapping sign (7/7). Patients with advanced age, air trapping sign and higher semi-quantitative score were found more likely to have abnormal blood gas index ( t=3.10, χ 2=9.38, t=3.34, P<0.05); patients with advanced age, underlying diseases, air trapping sign and higher semi-quantitative score were more likely to develop into severe disease ( t=2.68, χ 2=6.65, χ 2=4.25, t=4.33, P<0.05). The AUC of semi-quantitative score, air trapping sign and combination of two factors in distinguishing abnormal blood gas index from normal blood gas index was 0.803, 0.754 and 0.794 respectively. The AUC of semi-quantitative score, air trapping sign and combination of two factors in distinguishing cases with progression to severe cases from non-progression was 0.881, 0.898 and 0.932, respectively. Air trapping sign combined with semi-quantitative score significantly improved the prediction effectiveness of disease progression, compared with semi-quantitative score or air trapping sign (IDI=0.271, 0.117). Conclusion:Air trapping sign and semi-quantitative score might be used as effective indicators to predict the progression of COVID-19 cases, and the combination of these two factors might be more helpful to predict the disease progression.
