When a person's COVID symptoms persist for 12 weeks or more after an initial diagnosis, they are diagnosed with long COVID. A little over 6.5 percent of adults infected with the coronavirus end up with long COVID, according to CDC estimates.
Like COVID, long COVID symptoms tend to involve the lungs. Chest CT scans are often used to monitor lung function in adults with long COVID. The scans are not usually recommended for use in children, however, because they expose them to ionizing radiation and may require injection of a contrast agent.
Instead, the cardiopulmonary function of young patients suspected of having long COVID is usually evaluated with pulmonary tests, echocardiography and a review of the patient's medical history.Chronic fatigue, headaches and poor concentration are the most common symptoms of long COVID in children and teens. These symptoms can interfere with their school and social activities.
German researchers recently used a new type of MRI scan, a PREFUL (Phase-REsolved FUnctional Lung) MRI to address this issue. It allows them to track lung function without the need for breath-holding or contrast agents. They used the technology to analyze the movement of air in and out of the lungs and blood flow through the lungs in a group of children and teens between 11 and 17 years old. The method is good for kids because it does not require the use of radiation or the injection of a contrast agent.
“[PREFUL] MRI establishes an imaging biomarker profile and allows continuous follow up for this complex condition,” the lead author on the study, Gesa Pöhler, said in a statement. Children with long COVID should be monitored regularly for lung abnormalities to help parents and doctors make decisions about treatment.
Half of the 54 participants had long COVID and the other half did not — they served as controls. Almost all of those in the control group (96 percent) previously had COVID-19. Eighty-four percent of those in the long COVID group were vaccinated against SARS-CoV-2, the virus that causes COVID-19, and 89 percent of controls were vaccinated.
Children in the study who had long COVID had significantly reduced ventilation or breathing ability compared to the controls. Blood flow, or perfusion, through the lungs was significantly reduced in the long COVID group. Poor blood flow can mean that inadequate levels of oxygen and nutrients are circulating in the lungs.
Participants with long COVID in the current study filled out a questionnaire so researchers could determine the severity of their symptoms. Fatigue was the most common symptom in this group and was directly associated with the reduction of blood flow.
“The severity of fatigue was correlated with these changes in blood flow, suggesting a biological basis for patients' ongoing symptoms,” said Pöhler, a senior physician at Hannover Medical School in Germany.Children with long COVID should be monitored regularly for lung abnormalities to help parents and doctors make decisions about treatment.
A subgroup of 21 participants with long COVID had cardiopulmonary symptoms such as severe difficulty breathing, or dyspnea, and shortness of breath. They also had reduced ventilation and perfusion in the lungs compared to the control group. Going forward, longitudinal studies with larger study populations are needed to validate these findings.
