Imaging

Thoracic imaging is an important cornerstone in the diagnosis, monitoring and follow-up of admitted patients with pneumonia associated with COVID-19 caused by SARS-CoV-2. The most commonly used forms of thoracic imaging, encompassing lung ultrasound, chest radiography and CT, all possess acceptable sensitivities for the detection of COVID-19 with lung involvement but are flawed, with the typical findings being unspecific. As such, imaging results should always be critically appraised and correlated into the given clinical context. None of the thoracic imaging modalities is optimal for any given clinical scenario or setting, as what is practically feasible in one context may not be feasible in another. Local logistical factors, available healthcare resources, limitation of disease spread and safety of healthcare staff also need to be considered when determining the optimal choice of thoracic imaging. Hence, additional studies are warranted, especially assessing the optimal use of thoracic imaging for monitoring patients with COVID-19 during admission, but also for assessment of possible pulmonary COVID-19 sequelae.Copyright © ERS 2021.

Bronchoalveolar lavage fluid characteristics in patients with persistent symptoms following COVID-19 infection

A significant number of patients suffer from persistent symptoms following COVID-19 infection. However, data regarding the immunopathological mechanisms and potential biomarkers are limited. We investigated the differential cell count in the bronchoalveolar lavage fluid (BALF) in a post-COVID cohort. Patients presenting at the Vienna General Hospital within six months of a COVID-19 infection were enrolled. All patients underwent pulmonary function tests (PFT) and low-dose HRCT at baseline and at 6 and 12 months after a COVID-19 infection. Patients with pathological findings on HRCT or impairment in PFT were offered a bronchoscopy with BALF differential cell count via FACS analysis. Out of the 305 patients enrolled, 29 underwent bronchoscopy with bronchoalveolar lavage. After a median of 84 days following initial diagnosis of COVID-19, 25 showed persistent symptoms including dyspnoea (62.1%), fatigue (10.3%) and chest pain (10.3%). 24 patients showed pathological findings on HRCT consistent with COVID-19. While 11 patients developed a restrictive lung disease defined as TLC < LLN, 18 patients showed a reduced diffusion capacity defined as DLCO < 80%. Differential cell counts revealed that some patients showed lymphocytosis (7/29), increased eosinophil counts (5/29) and elevated neutrophils counts (2/29) in the BALF. Our preliminary data show that 34.5% of patients with persistent changes on HRCT have an elevated immune cell count with lymphocytosis being the predominant pattern. The degree of alveolar lymphocytosis might correlate with the severity of restrictive lung disease and might facilitate treatment decisions in patients with persistent symptoms following COVID-19.

COVID-19 pneumonia imaging follow-up: when and how? A proposition from ESTI and ESR.

This document from the European Society of Thoracic Imaging (ESTI) and the European Society of Radiology (ESR) discusses the role of imaging in the long-term follow-up of COVID-19 patients, to define which patients may benefit from imaging, and what imaging modalities and protocols should be used. Insights into imaging features encountered on computed tomography (CT) scans and potential pitfalls are discussed and possible areas for future review and research are also included. KEY POINTS: • Post-COVID-19 pneumonia changes are mainly consistent with prior organizing pneumonia and are likely to disappear within 12 months of recovery from the acute infection in the majority of patients. • At present, with the longest series of follow-up examinations reported not exceeding 12 months, the development of persistent or progressive fibrosis in at least some individuals cannot yet be excluded. • Residual ground glass opacification may be associated with persisting bronchial dilatation and distortion, and might be termed "fibrotic-like changes" probably consistent with prior organizing pneumonia.

Cardiopulmonary recovery after COVID-19: an observational prospective multicentre trial

BACKGROUND: After the 2002/2003 severe acute respiratory syndrome outbreak, 30% of survivors exhibited persisting structural pulmonary abnormalities. The long-term pulmonary sequelae of coronavirus disease 2019 (COVID-19) are yet unknown, and comprehensive clinical follow-up data are lacking. METHODS: In this prospective, multicentre, observational study, we systematically evaluated the cardiopulmonary damage in subjects recovering from COVID-19 at 60 and 100 days after confirmed diagnosis. We conducted a detailed questionnaire, clinical examination, laboratory testing, lung function analysis, echocardiography and thoracic low-dose computed tomography (CT). RESULTS: Data from 145 COVID-19 patients were evaluated, and 41% of all subjects exhibited persistent symptoms 100 days after COVID-19 onset, with dyspnoea being most frequent (36%). Accordingly, patients still displayed an impaired lung function, with a reduced diffusing capacity in 21% of the cohort being the most prominent finding. Cardiac impairment, including a reduced left ventricular function or signs of pulmonary hypertension, was only present in a minority of subjects. CT scans unveiled persisting lung pathologies in 63% of patients, mainly consisting of bilateral ground-glass opacities and/or reticulation in the lower lung lobes, without radiological signs of pulmonary fibrosis. Sequential follow-up evaluations at 60 and 100 days after COVID-19 onset demonstrated a vast improvement of symptoms and CT abnormalities over time. CONCLUSION: A relevant percentage of post-COVID-19 patients presented with persisting symptoms and lung function impairment along with radiological pulmonary abnormalities >100 days after the diagnosis of COVID-19. However, our results indicate a significant improvement in symptoms and cardiopulmonary status over time.