Radio-Histological Correlation of Lung Features in Severe COVID-19 Through CT-Scan and Lung Ultrasound Evaluation

Abstract

BackgroundPatients with coronavirus disease 2019 (COVID-19) can develop severe bilateral pneumonia leading to respiratory failure. Lung histological samples were scarce due to the high risk of contamination during autopsies. We aimed to correlate histological COVID-19 features with radiological findings through lung ultrasound (LU)-guided postmortem core needle biopsies (CNBs) and computerized tomography (CT) scans.MethodologyWe performed an observational prospective study, including 30 consecutive patients with severe COVID-19. The thorax was divided into 12 explorations regions to correlate LU and CT-scan features. Histological findings were also related to radiological features through CNBs.ResultsMean age was 62.56 ± 13.27 years old, with 96.7% male patients. Postmortem LU-guided CNBs were performed in 13 patients. Thirty patients were evaluated with both thoracic LU and chest CT scan, representing a total of 279 thoracic regions explored. The most frequent LU finding was B2-lines (49.1%). The most CT-scan finding was ground-glass opacity (GGO, 29%). Pathological CT-scan findings were commonly observed when B2-lines or C-lines were identified through LU (positive predictive value, PPV, 87.1%). Twenty-five postmortem echo-guided histological samples were obtained from 12 patients. Histological samples showed diffuse alveolar damage (DAD) (75%) and chronic interstitial inflammation (25%). The observed DAD was heterogeneous, showing multiple evolving patterns of damage, including exudative (33.3%), fibrotic (33.3%), and organizing (8.3%) phases. In those patients with acute or exudative pattern, two lesions were distinguished: classic hyaline membrane; fibrin “plug” in alveolar space (acute fibrinous organizing pneumonia, AFOP). C-profile was described in 33.3% and presented histological signs of DAD and lung fibrosis. The predominant findings were collagen deposition (50%) and AFOP (50%). B2-lines were identified in 66.7%; the presence of hyaline membrane was the predominant finding (37.5%), then organizing pneumonia (12.5%) and fibrosis (37.5%). No A-lines or B1-lines were observed in these patients.ConclusionLU B2-lines and C-profile are predominantly identified in patients with severe COVID-19 with respiratory worsening, which correspond to different CT patterns and histological findings of DAD and lung fibrosis.

Identification of Histopathological Biomarkers in Fatal Cases of Coronavirus Disease: A Study on Lung Tissue

“…Pulmonary interstitial fibrosis (PIF) is a condition characterized by the scarring of the lung tissue, which can impair lung function; the extent of interstitial fibrosis in COVID-19 patients is still poorly understood and remains an active area of research. Several studies have reported the development of PIF in patients with COVID-19, especially those with severe disease or who require mechanical ventilation [ 41 , 42 ]. In a cohort of 174 COVID-19 patients who underwent chest computed tomography (CT) scans, 25% had evidence of interstitial lung changes, including ground-glass opacities, consolidation, and reticulation, characteristic of PIF [ 43 ].…”

The Role of POCUS to Face COVID-19: A Narrative Review

“…This revealed the presence of diffused alveolar damage and lung fibrosis, which correlated with the C pattern, while jaline membranes, organized pneumonia, and fibrosis correlated with pattern B2. This kind of histological damage did not show a correlation to patterns A (A lines or isolated B lines) or B1 (multiple well-defined B-lines) [24].…”

Assessment of pulmonary fibrosis severity at autopsy in patients after COVID-19: comparison with quantitative CT scan data in the acute phase of the disease

“…The comparison of histological findings with CT imaging is of particular interest to study the pathogenesis of the disease. According to CT data, interstitial collagen deposition accompanied by type II pneumocyte hyperplasia is morphologically detected in the areas of lung damage [44]. The CT pattern of consolidation and ground-glass opacities (GGO) correlates with numerous pathologic processes, in particular with diffuse alveolar damage, capillary dilation and occlusion, and microthrombosis [45].…”