Longitudinal functional lung imaging in children with Post-COVID-19 syndrome

BACKGROUND: Respiratory distress and COVID-19-related symptoms persist as Post-COVID-19 syndrome (PCS) in a proportion of children and adolescents. We aimed to determine whether ventilation or perfusion defects constitute a possible cause for PCS. RESULTS: Mean ventilation was lower at baseline in vaccinated than in PCS (p=0.04) and V/Qmatchnon-defected increased from baseline to follow-up in vaccinated (p=0.03). In post-hoc comparison with historic data, V/Qmatchnon-defected improved in recovered (historic: 63.5±18.7%; baseline: 88.8±9.0%, p<0.0001; follow-up: 88.1±10.6%; p=0.0002) and PCS (historic: 57.3±19.5%; baseline: 86.1±7.6%, p<0.0001; follow-up: 86.6±7.7%, p=0.0110). Symptom load in PCS decreased from infection and baseline time points to 6-month follow-up. Laboratory assessments showed no differences. CONCLUSION: Despite persisting clinical symptoms, PREFUL MRI demonstrates no significant difference between cohorts, not supporting the hypothesis of persisting defects of the lung as causative.