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

Abstract

The objective of this study is to expound the CT features of COVID-19 patients whose throat swab samples were negative for two consecutive nucleic acid tests after treatment. 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 lung involvement were expounded. Thirty-nine moderate cases and seven severe/critical cases were included. Residual pulmonary lesions were visible in CT images. Moderate patients showed peripheral lesions while severe/critical cases exhibited both central and peripheral lesions with all lobes involvement. Mixed ground glass opacity (GGO) and pulmonary consolidation were noted. A larger proportion of severe patients showed reticular pulmonary interstitium thickening. Air bronchogram, pleural effusion, vascular enlargement, bronchial wall thickening, bronchiectasis, pleural thickening and pleural adhesion were more frequently observed in severe/critical group. The severe/critical group showed higher CT score. Pulmonary lesions persisted even after twice consecutive negative nucleic acid tests. We strongly recommended regular follow-up of CT scans after nucleic acid tests conversion. Evaluation of complete remission should base on chest CT. Coronavirus Disease-2019 (COVID-19) is an acute infectious disease mainly involving the respiratory system 1. The highly contagious disease is caused by a novel coronavirus currently termed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 1. So far to April 9, 2020, 1,479,748 cases of COVID-19 patients and 87,444 deaths are reported. It is a huge strike to human health and draws much attention from countries all over the world. At present, etiological examinations, including reverse transcription-polymerase chain reaction (RT-PCR) and gene sequencing of sputum, throat swab and lower respiratory tract secretion, are the gold standard for diagnosis of COVID-19 2. Nucleic acid tests are widely recognized as the primary criteria of discharge after treatment. However, it remains unclear whether damage to the lung have been completely restored when the nucleic acid tests are negative after treatment. Explanation of this issue is essential for determining the timing of treatment termination and isolation release. Chest computed tomography (CT) provides us a powerful noninvasive mean for the diagnosis and monitoring for COVID-19. Ground glass opacity (GGO) and consolidative opacity involving bilateral and peripheral lung were CT hallmarks of COVID-19 pneumonia 3-8. It has been reported that CT manifestations vary with the course of disease 8. However, post-treatment patterns of CT images after nucleic acid tests conversion have not yet been described, which are paramount for not only understanding the pathophysiology but also developing management strategies. In the present study, we assessed chest CT images...

The incidence of pleural effusion in COVID-19 pneumonia: State-of-the-art review

“…According to eight observational studies, the location of reported pleural effusions was unilateral in 66.8% (443/663) of cases, with the remainder bilateral in 33.2% (220/663) of patients. 13 , 14 , 15 , 16 , 17 , 18 , 19 In the two largest observational studies included in our review by Majidi et al and Feng et al, the incidence of pleural effusions were 7.6% and 5.7% among 552 and 442 COVID-19 patients, respectively. 20 , 21 A high incidence of pleural effusions ranging from 13.3% to 62.5% was reported in 14 observational studies reviewed ( Table 1 ).…”

“…Pleural retraction was only noted in three observational studies with a reported incidence of 41.7% (75/180). 14 , 32 , 46 Although pleural thickening was commonly observed in elderly COVID-19 patients who were age 60 years and older (71.4% versus 40.9%; p = 0.011), which might indicate higher disease severity such as ARDS with greater radiologic lung involvement, the incidence of pleural traction and effusion remained similar, regardless of age group. 47 In SARS patients, chest imaging during the late-stage of ARDS (two weeks and more) consisting of lung fibrosis and pleural thickening/retraction are similar to those seen in late-stage ARDS from alternative etiologies.…”

“… 32 Similar findings were noted collectively in several observational studies where critically ill COVID-19 patients had a greater likelihood of around 3.2-fold of developing pleural effusions at 33-43% versus 3-13% (p < 0.05) than non-critically ill COVID-19 patients. 14 , 19 , 29 , 32 , 75 Moreover, studies by Li et al and Liu et al described that pleural effusions were solely seen on chest CT in critically ill COVID-19 patients. 76 , 77 Although the inflammatory stress response in pregnant women towards viral pneumonia increased significantly during the middle and late stages of pregnancy, resulting in a rapid progression of the disease and severity of illness that may cause maternal-fetal death, the relationship between COVID-19-related pleural effusions and mortality in pregnancy were not assessed in observational studies and case series included in our review likely due to the small sample size.…”

“…Fourth, in all observational studies, we observed pleural effusions to be a bystander (minor secondary outcome) result or identified incidentally during subgroup analysis while assessing the many characteristics, risk factors, and outcomes of hospitalized COVID-19 patients. 7 , 14 , 20 , 75 , 77 Fifth, most diagnoses of COVID-19-related pleural effusions were made with the utilization of CT chest in observational studies included in our review, rendering the possible underdiagnosis of pleural effusions during this current pandemic. The use of routine chest imaging, including chest radiograph and CT, is understandably limited to reduce provider and radiology technician exposure to COVID-19 patients, unless a high clinical suspicion exists resulting from routine chest imaging may alter the overall decision-making and prognosis.…”

A Pictorial Review of the Role of Imaging in the Detection, Management, Histopathological Correlations, and Complications of COVID-19 Pneumonia

“…CT is also used during short-term follow-up of COVID-19 for clinical decision making to monitor the course of pneumonia in hospitalized patients, and it can also be used in symptomatic patients for long-term follow-up, as it can reveal late lung alterations [ 29 , 108 , 113 , 114 , 115 , 116 ]. Fu et al [ 117 ] suggested that CT was better than nucleic acid conversion in assessing final treatment outcomes. The diagnostic value of CT decreases in cases of low prevalence of COVID-19 disease [ 101 ].…”