New X-ray technology can identify the long-term damage that severe Covid-19 can inflict on the lungs, including the ‘microclots’ often associated with long Covid.
The breakthrough has come, however, as research has also concluded the UK now has the highest rate for pneumonia deaths in Europe.
The high-energy X-ray technique, called ‘Hierarchical Phase-Contrast Tomography’ (HiP-CT), has been developed by scientists from UCL and the European Synchrotron Research Facility (ESRF).
It enables whole organs to be scanned down to cellular level, so allowing clinicians to view blood vessels about a tenth of the diameter of a human hair.
The technology can be used to reveal microscopic lung clots and changes in blood vessels that have only been found in pulmonary fibrosis associated with Covid-19, further improving our understanding of the long-term effects of serious Covid-19 infection, or long Covid. It can also be used to distinguish between Covid-related lung scarring and non-Covid-related pulmonary fibrosis, which also causes severe scarring of lung tissue.
Around 20% of patients who survive severe Covid-19 (requiring hospitalisation) go on to develop pulmonary fibrosis. Typical life expectancy for the disease is around three to five years after diagnosis.
In a paper published in the journal eBioMedicine, clinicians used HiP-CT to examine the intact lungs of patients who had passed away after contracting Covid-19.
The team, from RWTH Aachen University Hospital, Hannover Medical School, HELIOS University Hospital in Wuppertal and the University Medical Centre Mainz, all in Germany, together with UCL and the ESRF, discovered a distinctive mosaic-like pattern of damage in the lungs that hasn’t been seen before.
The experts also compared blood samples from Covid-19 patients with those from some common and serious lung diseases, including pulmonary fibrosis unrelated to Covid-19.
The team concluded that the microscopic clots, seen within tiny blood vessels, cause the distinctive pattern and drive inflammation in the lungs that can lead to long Covid symptoms, such as shortness of breath and disease such as pulmonary fibrosis.
The team say they hope that identifying the tiny clots found in damaged lung tissue and the changes in microscopic blood vessels can serve as an early indicator of Covid-induced pulmonary fibrosis, for which there is no cure. They also hope this will allow clinicians time to administer treatment to potentially lessen the impact and improve patients’ quality of life.
Co-author Dr Claire Walsh, from UCL’s Mechanical Engineering Department, who co-developed HiP-CT with ESRF, said: “A technique like HiP-CT is a real game-changer for unveiling not only the really fine detail of the tissue damage, but also how it is distributed across a whole organ and relating that back to what is seen in clinic.
“This technology allows us to understand more about the impact that severe Covid-19 can have on the lungs and will help us when diagnosing and treating pulmonary fibrosis resulting from the virus.”
UK worst in Europe for pneumonia deaths
Separately, analysis by the lung charity Asthma + Lung UK has concluded that more people die from pneumonia in the UK than anywhere else in Europe.
The charity has launched a campaign to raise awareness of the signs and symptoms of pneumonia and is urging people who are eligible, such as those with severe asthma, pulmonary fibrosis and chronic obstructive pulmonary disease (COPD), to get their one-off pneumonia vaccine. Adults at an occupational risk, such as metal workers and welders, are also eligible for the vaccine.
The charity’s analysis has revealed that each year more than 25,000 people die from pneumonia in the UK. The UK also has the third highest death rate from pneumonia in Europe.
Sarah Woolnough, chief executive at Asthma + Lung UK, said: “It’s shocking the UK has the most deaths from pneumonia in Europe. The state of lung health in the UK isn’t good enough and we must do better to protect people from life-threatening chest infections, such as pneumonia.”