Characterization of COVID-19-Related Lung Involvement in Patients Undergoing Magnetic Resonance T1 and T2 Mapping Imaging: A Pilot Study.

Tissue characterization by mapping techniques is a recent magnetic resonance imaging (MRI) tool that could aid the tissue characterization of lung parenchyma in coronavirus disease-2019 (COVID-19). The aim of the present study was to compare lung MRI findings, including T1 and T2 mapping, in a group of n = 11 patients with COVID-19 pneumonia who underwent a scheduled cardiac MRI, and a cohort of healthy controls. MRI scout images were used to identify affected and remote lung regions within the patients' cohort and appropriate regions of interest (ROIs) were drawn accordingly. Both lung native T1 and T2 values were significantly higher in the affected areas of patients with COVID-19 as compared to the controls (1375 ms vs. 1201 ms, p = 0.016 and 70 ms vs. 30 ms, p < 0.001, respectively), whereas no significant differences were detected between the remote lung parenchyma of the COVID-19 patients and the controls (both p > 0.05). When a larger ROI was identified, comprising the whole lung parenchyma within the image irrespective of the affected and remote areas, the COVID-19 patients still retained higher native T1 (1278 ms vs. 1149 ms, p = 0.003) and T2 values (38 ms vs. 34 ms, p = 0.04). According to the receiver operator characteristics curves, the T2 value of the affected region retained the higher accuracy for the differentiation of the COVID-19 patients against the controls (area under the curve 0.934, 95% confidence interval 0.826−0.999). These findings, possibly driven by the ability of MRI tissue mapping to detect ongoing inflammation in the lungs of patients with COVID-19, suggest that T1 and T2 mapping of the lung is a feasible approach in this clinical scenario.

Semiquantitative Chest CT Severity Score Predicts Failure of Noninvasive Positive-Pressure Ventilation in Patients Hospitalized for COVID-19 Pneumonia.

OBJECTIVE: Noninvasive positive-pressure ventilation (NPPV) emerged as an efficient tool for treatment of COVID-19 pneumonia. The factors influencing NPPV failure still are elusive. The aim of the study was to investigate the relationships between semiquantitative chest computed tomography (CT) scoring and NPPV failure and mortality in patients with COVID-19. DESIGN: Observational study. SETTING: Nonintensive care setting. PARTICIPANTS: A total of 112 patients consecutively admitted for COVID-19 pneumonia. INTERVENTIONS: Usual care including various degrees of respiratory support. MEASUREMENTS AND MAIN RESULTS: The semiquantitative CT score was calculated at hospital admission. Subgroups were identified according to the ventilation strategy used (oxygen delivered by Venturi mask n = 53; NPPV-responder n = 38; NPPV-failure n = 21). The study's primary endpoint was the use of NPPV. The secondary endpoints were NPPV failure and in-hospital death, respectively. CT score progressively increased among groups (six v nine v 14, p < 0.05 among all). CT score was an independent predictor of all study endpoints (primary endpoint: 1.25 [95% confidence interval {CI} 1.1-1.4], p = 0.001; NPPV failure: 1.41 [95% CI 1.18-1.69], p < 0.001; in-hospital mortality: 1.21 [95% CI 1.07-1.38], p = 0.003). According to receiver operator characteristics curve analysis, CT score was the most accurate variable for prediction of NPPV failure (area under the curve 0.862 with p < 0.001; p < 0.05 v other variables). CONCLUSIONS: The authors reported the common and effective use of NPPV in patients with COVID-19 pneumonia. In the authors' population, a semiquantitative chest CT analysis at hospital admission accurately identified those patients responding poorly to NPPV.

Heart and lung tissue characterization of COVID-19 pneumonia by T1 and T2 mapping magnetic resonance imaging

Aims Coronavirus disease 2019 (COVID-19) is a respiratory tract infection which can lead to systemic involvement including myocardial injury, severe respiratory failure and death. Magnetic resonance imaging (MRI) could potentially offer advantages in providing tissue characterization of lung parenchyma and heart muscle in COVID-19. The aim of the present study was to describe data on heart and lung MRI in a cohort of patients hospitalized due to COVID-19 pneumonia. Methods and results n = 11 patients hospitalized with COVID-19 pneumonia underwent a comprehensive MRI examinations including lung and heart tissue mapping, findings were compared to those of an age- and sex-matched cohort of n = 11 individuals. Lung native T1 and T2 mapping assessments were performed by drawing a circular region of interest (ROI) with diameter of 2 cm in the parenchyma visualized from the cardiac four chamber long axis-oriented slice;vessels and areas of pleural effusion were carefully excluded. Myocardial native T1 and T2 mapping were assessed by drawing a ROI within the midventricular left ventricular (LV) septum. No patients had previous history of cardiovascular disease (including known coronary artery disease, heart failure, cardiomyopathy, atrial fibrillation). As compared to controls, patients with COVID-19 had similar cardiac function, higher mid-septum myocardial native T1 (1028 ms vs. 985, P = 0.05) and significantly higher lung native T1 and T2 within affected areas (1375 ms vs. 1201 ms, P = 0.016 and 70 ms vs. 30 ms, P < 0.001 respectively), whereas non-significant differences were observed between remote lung areas of patients and controls (1238 ms vs. 1152 ms, P = 0.088 and 29 ms vs. 33 ms, P = 0.797 respectively). No significant associations were observed between cardiac and lung mapping findings. Conclusions In our cohort of patients with COVID-19, T1 and T2 mapping lung MRI identified pneumonia related abnormalities as compared to healthy controls, likely representing oedema and ongoing inflammation at the lung site. Myocardial native T1 was elevated suggesting the presence of cardiac involvement. A comprehensive MRI examination can be potentially used to assess multiorgan involvement in COVID-19.

Lung Ultrasound in COVID-19: Clinical Correlates and Comparison with Chest Computed Tomography.

Lung ultrasound (LUS) and chest computed tomography (chest CT) are largely employed to evaluate coronavirus disease 2019 (COVID-19) pneumonia. We investigated semi-quantitative LUS and CT scoring in hospitalized COVID-19 patients. LUS and chest CT were performed within 24 h upon admission. Both were analyzed according to semi-quantitative scoring systems. Subgroups were identified according to median LUS score. Patients within higher LUS score group were older (79 vs 60 years, p<0.001), had higher C-reactive protein (CRP) (7.2 mg/dl vs 1.3 mg/dl, p<0.001) and chest CT score (10 vs 4, p=0.027) as well as lower PaO2/FiO2 (286 vs 356, p=0.029) as compared to patients within lower scores. We found a significant correlation between scores (r=0.390, p=0.023). Both LUS and CT scores correlated directly with patients age (r=0.586, p<0.001 and r=0.399, p=0.021 respectively) and CRP (r=0.472, p=0.002 and r=0.518, p=0.002 respectively), inversely with PaO2/FiO2 (r=-0.485, p=0.003 and r=-0.440, p=0.017 respectively). LUS score only showed significant correlation with hs-troponin T, NT-pro-BNP, and creatinine (r=0.433, p=0.019; r=0.411, p=0.027, and r=0.497, p=0.001, respectively). Semi-quantitative bedside LUS is related to the severity of COVID-19 pneumonia similarly to chest CT. Correlation of LUS score with markers of cardiac and renal injury suggests that LUS might contribute to a more comprehensive evaluation of this heterogeneous population.