A new type of imaging technology has detected lung damage in patients suffering from the long-term effects of COVID-19. The weakened lung function was not visible on standard MRI or CT scans and its detection will help clinicians understand the persistent breathing impairments seen in patients with long COVID.
The phenomenon of long COVID is still a bit of a mystery, with researchers only just beginning to grasp the long-term implications of infection with this novel coronavirus. Fatigue and breathlessness are two of the most commonly reported lingering symptoms in COVID-19 patients following discharge from hospital. Yet standard MRI and CT scans often deliver normal results leaving many clinicians unable to empirically explain these patient symptoms.
An ongoing study in the UK, called PHOSP-COVID, is tracking a large number of patients closely for many months following hospitalization, and a small arm of that study is investigating long-term lung problems in this cohort.
The research is using a new kind of imaging technology called hyperpolarized xenon MRI (129Xe MRI). The technology offers incredibly detailed insights into lung function and gas transfer into the bloodstream.
“The 129Xe MRI is pinpointing the parts of the lung where the physiology of oxygen uptake is impaired due to long standing effects of COVID-19 on the lungs, even though they often look normal on CT scans,” says Jim Wild, head of imaging at the University of Sheffield.
The study is small, involving scans from nine long COVID patients, averaging around six months post-hospitalization. All nine subjects reported persistent breathlessness and all nine subjects returned normal CT lung scans.
“Our follow-up scans using hyperpolarized 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,” says Fergus Gleeson, a radiologist working on the new study.
The revolutionary imaging technique is offering some of the first empirical signs of lung damage in long COVID patients, affirming this is not merely a hypochondriacal condition. The findings also offer researchers a useful way to monitor lung damage, with future studies now able to track how long the damage may last for, and whether any particular interventions can help.
“We have some way to go before fully comprehending the nature of the lung impairment that follows a COVID-19 infection,” adds Gleeson. “But these findings, which are the product of a clinical-academic collaboration between Oxford and Sheffield, are an important step on the path to understanding the biological basis of long COVID and that in turn will help us to develop more effective therapies.”
The new study was published in the journal Radiology.
Source: University of Sheffield