Background: Coronavirus disease 2019 (COVID-19) induces myocardial injury, either direct myocarditis or indirect injury due to systemic in ammatory response. Myocardial involvement has been proved to be one of the primary manifestations of COVID-19 infection, according to laboratory test, autopsy, and cardiac magnetic resonance imaging (CMRI). However, the middle-term outcome of cardiac involvement after the patients were discharged from the hospital is yet unknown. The present study aimed to evaluate mid-term cardiac sequelae in recovered COVID-19 patients by CMRI Methods: A total of 47 recovered COVID-19 patients were prospectively recruited and underwent CMRI examination in this study. The CMRI protocol consisted of black blood fat-suppressed T2 weighted imaging (BB-T2WI), T2 star mapping, left ventricle cine imaging, pre-and post-contrast T1 mapping, and late gadolinium enhancement (LGE). Myocardium edema and LGE were assessed in recovered COVID-19 patients. The left ventricle (LV) and right ventricle (RV) function and LV mass were assessed and compared with normal controls. Results: Finally, 44 recovered COVID-19 patients and 31 normal controls were included in this study. No edema was observed in any patient. LGE was found in 13 patients. All LGE lesions were located in the middle myocardium and/or sub-epicardium with a scattered distribution. Further analysis showed that LGE-positive patients had signi cantly decreased left ventricle peak global circumferential strain (LVpGCS), right ventricle peak global circumferential strain (RVpGCS), right ventricle peak global longitudinal strain (RVpGLS) as compared to non-LGE patients (p 0.05), while no difference was detected between the non-LGE patients and normal controls. Conclusion: Myocardium injury existed in about 30% of COVID-19 patients. These patients had peak right ventricle strain that decreased at the 3-month follow-up. Cardiac MRI can monitor the COVID-19-induced myocarditis progression, and CMR strain analysis is a sensitive tool to evaluate the recovery of left ventricle circumferential contraction dysfunction and right ventricular dysfunction.

The recovery process of COVID-19 patients is unclear. Some recovered patients complain of continued shortness of breath. Vasculopathy has been reported in COVID-19, stressing the importance of probing microstructure and function of lungs at the alveolar-capillary interface. While CT detects structural abnormalities, little is known about the impact of disease on lung function. 129Xe MRI is a technique uniquely capable of assessing ventilation, microstructure and gas exchange. Using 129Xe MRI, we found COVID-19 patients have higher ventilation defects percentage (5.9% vs 3.7%), unchanged microstructure, longer gas-blood exchange time (43.5 ms vs 32.5 ms), and reduced RBC/TP (0.279 vs 0.330) compared with healthy subjects. These findings suggest regional ventilation and alveolar airspace dimensions are relatively normal around the time of discharge, while gas-blood exchange function is diminished. This study establishes the feasibility of localized lung function measurement in COVID-19 patients. Such readouts could be useful as a supplement to structural imaging.

BackgroundThe clinical value of novel mapping techniques and strain measures to assess myocardial inflammation in fulminant myocarditis (FM) has not been fully explored.PurposeTo evaluate the ability of mapping and strain cardiac MRI to assess myocardial inflammation in patients with FM, and to which degree the strain metrics correlate with myocardial edema.Study TypeProspective.PopulationTwenty‐nine patients (37 ± 16 years, 48% male) with FM and 29 patients with nonfulminant acute myocarditis (NFAM) (29 ± 14 years, 69% male).Field Strength/Sequence3.0T; Cine imaging, black blood T2‐weighted imaging, T1mapping, T2 mapping, and late gadolinium enhancement.AssessmentNative T1, extracellular volume (ECV), and T2 were measured. Myocardial strain was evaluated by feature tracking.Statistical TestsStudent's t‐ or Mann–Whitney U‐test. Spearman correlation analysis.ResultsThe myocardial edema rate (2.6 ± 0.7 vs. 1.6 ± 0.2, P < 0.001) and late gadolinium enhancement (LGE) mass (16.5 [11.7, 41.7] vs. 6.9 [2.2, 15.8] g, P < 0.001) were significantly increased in FM patients when compared to the NFAM group. LGE in the FM group was predominantly located in the septal wall, and 38% of the patients showed a diffuse LGE pattern. Native T1, ECV, and T2 values in the FM group were significantly more elevated than those with NFAM, while global peak radial, circumferential, and longitudinal strain values were significantly reduced (all P < 0.001). Circumferential strain showed the strongest correlations with ECV (r = 0.72, P < 0.001).Data ConclusionPatients with FM showed significant differences in LGE patterns, increased edema, and decreased strain measurements compared to those with NFAM. Circumferential strain showed significant associations with quantitative cardiac MRI parameters of myocardial inflammation.Level of Evidence2Technical Efficacy Stage2 J. Magn. Reson. Imaging 2020;52:930–938.