SARS-CoV-2 (Severe acute respiratory syndrome coronavirus type 2) is a new coronavirus and identified causative agent of COVID-19 disease. They predominantly cause mild colds but can sometimes cause severe pneumonia. The long-term consequences are still largely unexplained and misunderstood, especially in children and adolescents. The aim of this study is to assess the frequency of pulmonary skeletal changes in pediatric and adolescent patients using low-field magnetic resonance imaging (LF-MRI) in the setting of proven past SARS-CoV-2 infection.

SARS-CoV-2 (Severe acute respiratory syndrome coronavirus type 2) is a new coronavirus and identified causative agent of COVID-19 disease. They predominantly cause mild colds, but can sometimes cause severe pneumonia. While the molecular basis for the changes in lung tissue or multi-organ involvement has been described, the age-specific long-term consequences, especially in children and adolescents, are still largely unexplained and not understood. Early publications from the primarily affected Chinese provinces described rather mild, partly asymptomatic courses in children. This is consistent with the observation that the risk of severe COVID-19 disease increases steeply from the age of 70 years, and is also determined by the severity of obesity and other risk factors. Developmental expression of tissue factors may be one reason for the relative protection of younger patients from severe courses of the disease.

However, it is now becoming increasingly clear that some individuals with milder initial symptoms of COVID-19 may suffer from variable and persistent symptoms for many months after initial infection - this includes children. A modern low-field MRI is located in Erlangen, Germany. This technique has already been used to demonstrate persistent damage to lung tissue in adult patients after COVID-19. The device with a field strength of 0.55 Tesla (T) currently has the world's largest bore (and is thus particularly suitable for patients with claustrophobia, among other things), a very quiet operating noise, and lower energy absorption in the tissue due to the weaker magnetic field than MRI scanners with 1.5T or 3T. This allows MRI imaging in a very wide pediatric population without the need for sedation.

The purpose of this study is to assess the frequency of lung parenchymal changes using low-field magnetic resonance imaging (LF-MRI) in pediatric and adolescent patients with past SARS-CoV-2 infection detected by PCR.

Covid-19 group

Inclusion Criteria:

• (Past) Positive SARS-CoV-2 Infection (PCR proven)
• Age 5 to <18 years

Exclusion Criteria:

• Acute SARS-CoV-2 Infection and Isolation
• Quarantine
• Pregnancy
• Critical Illness
• No consent to LF_MRI
• General contraindications for LF-MRI, such as electrical implants, pace makers, perfusion pumps)

Healthy controls

Inclusion Criteria:

- Age 5 to <18 years

Exclusion Criteria:

• (Past) Positive SARS-CoV-2 Infection (PCR or antigen test proven)
• Suspect for lung disease
• Acute respiratory infection/symptomatic
• Acute SARS-CoV-2 Infection and Isolation
• Quarantine
• Pregnancy
• Critical Illness
• No consent to LF_MRI
• General contraindications for LF-MRI, such as electrical implants, pace makers, perfusion pumps)

Individual participant data that underlie the results reported in the primary publication, after deidentification (text, tables, figures, and appendices)

Beginning 9 months and ending 36 months following article publication.

The data sets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request as follows:

Individual participant data will not be available Study Protocol and Statistical Analysis Plan will be available The data will be available beginning 9 months and ending 36 months following article publication.

The data will be available to researchers who provide a methodologically sound proposal.

The data will be available for individual participant data meta-analysis, only. Proposals may be submitted up to 36 months following article publication. After 36 months the data will be available in our University's data warehouse but without investigator support other than deposited metadata. Information regarding submitting proposals and accessing data may be found at https://www.uk-erlangen.de.

Restrictions may apply due to patient privacy and the General Data Protection Regulation.