What the researchers measured
Oxford's January 31, 2022 account of the EXPLAIN research described hyperpolarized xenon MRI scans in a small group of people with persistent breathlessness after COVID-19 who had not been hospitalized. The method tracked movement of inhaled xenon from the lungs into the bloodstream, revealing abnormalities not apparent on their routine CT scans.
A scan measuring gas transfer asks a different question from an image primarily showing lung structure. Different tests can therefore reveal different aspects of physiology without one result automatically invalidating another.
Source [1]The limits are part of the finding
Oxford explicitly described the results as initial and said a larger study was underway. The early group cannot establish how common the finding is across everyone with long COVID, how long every abnormality persists or which treatment will help a particular patient.
The useful conclusion is narrower: a specialized research method identified a possible physiological explanation worth investigating in some patients with breathlessness. It does not justify diagnosing yourself from a headline, assuming irreversible damage or dismissing symptoms because a standard scan was normal. The linked Health section separates current reporting from this dated study account.
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