The University of Oxford in the UK studied 10 patients using a scanning technique to detect changes left hidden during standard health scans.
The new method involves MRI scans that use xenon gas to generate a clear picture of lung damage.
Lung experts said the new testing technique, if it was successful in detecting lung damage, “would make a huge difference for patients with COVID-19.”
The xenon method involves patients inhaling the gas during an MRI scan. Professor Fergus Gleeson, who is leading the study, used the new method on 10 patients aged 19 to 69.
The results showed that eight patients suffered from shortness of breath and fatigue three months after infection with COVID-19, although none of them received intensive care or ventilation, and conventional health examinations did not detect no lung damage.
But the new scans found signs of lung damage in eight patients by exposing areas where air did not flow easily through the blood.
Gleeson is now looking to expand the study by testing up to 100 people who have not been admitted to hospital and have not suffered severe symptoms. The aim is to find out if lung damage occurs and, if so, its extent and duration.
“I expected some form of lung injury, but not the degree that we saw,” Gleeson said.
If the trial finds lung damage to occur across a broad age group and in people with minor symptoms, “that would shift the targets,” he added.
The lung damage revealed by the new scans could be a factor behind the “long COVID,” where people get sick for months after infection, he said.
The xenon scanning technique was developed by researchers at the University of Sheffield in the UK, led by Professor James Wild.
“In other fibrous lung disease, we have shown that the methods are very sensitive to this deficiency and we hope the work can help understand COVID-19 lung disease,” Wild said.
Dr Shelley Hayles, who worked on the study, said: “Up to 10 percent of those who have had COVID-19 could have some form of lung injury that results in prolonged symptoms.
“When the medical staff tell patients that they don’t know what’s wrong with them and that they don’t know how to deal with the symptoms, it is very stressful. With most patients, even if the news is not good, they want the diagnosis. ”