A recent study at the University of Sheffield in the UK has detected previously unseen lung damage in long-term Covid-19 patients using a new scanning technique.
The technique, which involves hyperpolarised xenon gas and MRI scanning to allow imaging of oxygen uptake in the lungs, has identified weakened lung function in Covid-19 patients not visible on a standard MRI or CT scan.
Researchers are working with 40 patients in Sheffield and Oxford over the next six months. So far, the hyperpolarised xenon MRI technique has identified weakened lung function in all 7 of the patients who have taken part in the study so far.
The detected reduction in lung function may explain why some patients experience persistent Long COVID symptoms despite seemingly ‘normal’ results from standard GP and hospital tests, said one of the researchers.
How many people have Long COVID is not clear. A Swiss study found a third of mild cases had symptoms after 2 months. One published in the UK in mid November found 70% of a sample of young low-risk patients had some sort of organ damage after 4 months. Another study in the UK suggests around 1 in 20 people contracting the disease will suffer from Long COVID – symptoms lasting over 8 weeks. The samples in these studies are different and it isn’t clear how long Long COVID lasts so it is difficult to form any conclusions. However, over the medium term at least, the number of Long COVID sufferers is likely to be significantly higher than those requiring hospitalisation with the disease.
Professor Fergus Gleeson, the University of Oxford’s Head of Academic Radiology involved in the new lung scanning study, said that “We may be getting an insight into why some patients have symptoms long after they have left hospital, and when other tests are normal. This may help us identify patients that may potentially benefit from treatment even after discharge, for example with steroids or other therapies.”
University of Sheffield article (in English)