CT features of COVID-19 patients with two consecutive negative RT-PCR tests after treatment

Abstract Purpose: The objective of this study is to expound the CT features of COVID-19 patients whose nucleic acid tests converted to negative after treatment.Materials and Methods: We retrospectively reviewed 46 COVID-19 patients with two consecutive negative RT-PCR tests after treatment. The cases were divided into moderate group and severe/critical group according to disease severity. Clinical and CT scanning data were collected. CT signs of pulmonary lesions and the score of long involvement were expounded.Results: 39 moderate cases and 7 severe/critical cases were included. All moderate patients showed peripheral lesions while severe/critical cases exhibited both central and peripheral lesions with all lobes involvement. Ground glass opacity (GGO) and mixed GGO were observed. Aberrant pulmonary interstitium manifested as reticular and thin linear pattern. Thickened blood vessels and pleural thickening were found. Pulmonary fibrosis, annular thickening of the bronchial wall, bronchiectasis, air bronchogram and small amount of bilateral pleural effusion were observed in severe/critical patients. The severe/critical group showed higher CT score of involvement.Conclusions: Pulmonary lesions persisted even after twice consecutive nucleic acid tests converted to negative. We strongly recommended regular follow-up of CT scans after nucleic acid tests conversion. Evaluation of complete remission should base on chest CT.