This damage was not detected by routine CT scans and clinical tests, and the patients would consequently normally be told their lungs are normal.
Further early research by the team has shown that patients who have not been hospitalised with COVID-19 but who are experiencing long-term breathlessness may have similar damage in their lungs, and a larger study is needed to confirm this.
In a paper published in Radiology, the world’s leading radiology journal, the researchers from Oxford and Sheffield said that hyperpolarised xenon MRI (XeMRI) scans had found abnormalities in the lungs of some COVID-19 patients more than three months – and in some cases, nine months - after leaving hospital, when other clinical measurements were normal.
The study’s Principal Investigator Professor Fergus Gleeson, Professor of Radiology in the Department of Oncology, (University of Oxford) and Consultant Radiologist at Oxford University Hospitals (OUH) NHS Foundation Trust, said: “Many COVID-19 patients are still experiencing breathlessness several months after being discharged from hospital, despite their CT scans indicating that their lungs are functioning normally.
“Our follow-up scans using hyperpolarised xenon MRI have found that abnormalities not normally visible on regular scans are indeed present, and these abnormalities are preventing oxygen getting into the bloodstream as it should in all parts of the lungs.”