By Stephen Beech

Worrying lung abnormalities have been detected in youngsters with long COVID.

An advanced type of MRI scan uncovered “significant” problems – including reduced blood flow – in the lungs of children and teenagers suffering from the long-term effects of the COVID-19 virus.

Doctors say long COVID-19 can affect people of all ages and is diagnosed when symptoms persist for more than 12 weeks after an initial COVID-19 infection.

Children and adolescents usually experience a milder form of the condition, but common symptoms – such as chronic fatigue, headaches and poor concentration – can have a negative impact on academic performance and social activities.

While CT scans are often used to diagnose and monitor lung function of adults with long COVID, scientists say it is not usually recommended in children because it exposes the patient to ionizing radiation and may require the injection of a contrast agent.

Young patients with suspected long COVID are typically evaluated using pulmonary function tests, echocardiography and reviews of medical history.

However, conventional pulmonary tests often show normal lung and cardiac function, even in symptomatic patients.

Study lead author Doctor Gesa Pöhler, of Hannover Medical School in Germany, said: “Parents should understand that their children’s persistent symptoms after COVID-19 may have a measurable physiological basis, even when standard medical tests appear normal.”

The researchers employed phase-resolved functional lung (PREFUL) MRI, an advanced MRI technology that can analyze lung ventilation – air movement in and out of the lungs – and perfusion, blood flow through the lungs.

The team explained that PREFUL MRI doesn’t require the use of radiation or intravenous contrast agents and can be done while the patient breathes freely, making it a suitable procedure for children.

Dr. Pöhler said: “Our research provides the first comprehensive evidence of measurable regional lung perfusion abnormalities in pediatric post-COVID-19 conditions using radiation-free, contrast-free lung imaging.”

A total of 54 patients, aged 11 to 17, were enrolled for the study, conducted between April 2022 and 2023.

Half of the patients were diagnosed with long COVID, and the other half were healthy controls.

A self-reported assessment – called the “bell score” – was used to assess symptom severity in the long COVID patients.

The findings, published in the journal Radiology, showed that children and teenagers with long COVID had “significantly” reduced blood flow in the lungs, compared to the healthy controls.

A reduction in blood flow patterns in organs or other areas of the body can result in a lack of sufficient oxygen and nutrients.

The most prevalent symptom of fatigue affected all but one patient with long COVID.

Dr. Pöhler said: “Importantly, the severity of fatigue symptoms correlated with these blood flow changes, suggesting a possible biological basis for the patient’s ongoing symptoms.”

As well as poor blood flow, a subgroup of long COVID patients with cardiopulmonary symptoms – such as shortness of breath – also showed a reduction of air movement and reach in the lungs.

The researchers suggest that continuous monitoring of lung abnormalities in children with long COVID at various stages of the condition could help guide treatments.

Dr. Pöhler added: “Quantitative lung MRI establishes a potential imaging biomarker profiling and helps to enable disease severity follow-up for this complex condition in the future.”