Abstract:

Objective To retrospectively analyze CT manifestations and clinical features of 23 COVID⁃19patients with re⁃positive nucleic acid. Methods A retrospective analysis was conducted on chest CT manifesta⁃tions and clinical characteristics of 23 COVID⁃19 patients with re⁃positive nucleic acid in Guangzhou No.8 People′sHospital from January 24 to March 15，2020，including 12 males and 11 females，aged 19~79，with an averageage of 46.61 ± 17.86. Results Twenty⁃three cases were all normal COVID⁃19 patients，3 of which had gastricanorexia but without other symptoms. Anal swab of 15 cases was positive（65.2%）；throat swab was positive in 7cases（30.4%）and nasal swab in 1 case（4.4%）. The time nucleic acid converting from negative to re⁃positive inanal swab and throat swab was 6.87 ± 3.31 and 7.14 ± 4.06 days respectively and the time nucleic acid convertingfrom re⁃ositive to negative 6.53 ± 4.93 and 2.71 ± 1.50 days respectively. Chest CT showed that lesions involvedwith bilateral lung lobes in 16 cases and unilateral lobe in 7 cases. Lesions were distributed in the upper and middlelobe in 3 cases；in the lower lobe and under the pleura in 14 cases，and in the lung in 7 cases. There were 20 casesof small patchy or nodular ground glass density changes in the lung，14 cases with increased cord density，4 caseswith thickening of adjacent pleura，1 case of thickening of interstitial septum，and 11 cases of thickening andthickening of bronchovascular bundles in both lungs. The bronchioles were stretched and dilated in 2 cases andpleural effusion in 1 case. Compared with CT images before re⁃positive nucleic acid found，1 case of inflammationwas more severe；5 cases had no significant change and 16 cases of inflammation were improved. Conclusion Inthis paper，data of 23 normal COVID⁃19 patients in Guangzhou are analyzed. After the nucleic acid turned out to bepositive again，there are only 3 cases with gastric anorexia but no sign of pain and no other clinical manifestationsare observed. Re⁃positive nucleic acid is tested out within 14 days after the discharge when patients are still isolated in the designated places then nucleic acid turned out to be negative again within 14 days and no recurrence is foundin the follow⁃up. CT images of patients with re⁃positive nucleic acid showed no severe symptoms than before. Themain manifestations are multiple small ground⁃glass shadows ，increased density of cord⁃like densities ，moreinvolvement of both lungs，more common in the lower lobe of the lung and the subpleural，and more pulmonarybronchial vascular bundles increase and thickening，but few pleural effusions

Key words: COVID?19, re?positive nucleic acid, CT, ground glass opacity