Scientists from UCL and the European Synchrotron Research Facility (ESRF) used a new revolutionary imaging technology called Hierarchical Phase-Contrast Tomography (HiP-CT), to scan donated human organs, including lungs from a Covid-19 donor.

HiP-CT enables 3D mapping across a range of scales, allowing clinicians to view the whole organ as never before by imaging it as a whole and then zooming down to cellular level.

The technique uses X-rays supplied by the European Synchrotron (a particle accelerator) in Grenoble, France, which following its recent Extremely Brilliant Source upgrade (ESRF-EBS), now provides the brightest source of X-rays in the world at 100 billion times brighter than a hospital X-ray.
Due to this intense brilliance, researchers can view blood vessels five microns in diameter (a tenth of the diameter of a hair) in an intact human lung. A clinical CT scan only resolves blood vessels that are about 100 times larger, around 1mm in diameter.

Dr Claire Walsh (UCL Mechanical Engineering) said: “The ability to see organs across scales like this will really be revolutionary for medical imaging. As we start to link our HiP-CT images to clinical images through AI techniques, we will - for the first time - be able to highly accurately validate ambiguous findings in clinical images. For understanding human anatomy this is also a very exciting technique, being able to see tiny organ structures in 3D in their correct spatial context is key to understanding how our bodies are structured and how they therefore function.”

Using HiP-CT, the research team, which includes clinicians in Germany and France, have seen how severe Covid-19 infection ‘shunts’ blood between the two separate systems – the capillaries which oxygenate the blood and those which feed the lung tissue itself. Such cross-linking stops the patient’s blood from being properly oxygenated, which was previously hypothesised but not proven.

Maximilian Ackermann MD (University Medical Center Mainz), clinical user of the technique, said: “Shortly after the beginning of the global pandemic we demonstrated that Covid-19 is a systemic vascular disease using histopathological (optical imaging of tissue) and molecular methods. However, these techniques did not adequately address the extent of the changes and clotting in fine blood vessels of whole lungs.”

Danny Jonigk, Professor of Thoracic Pathology, (Hannover Medical School, Germany) said “By combining our molecular methods with the HiP-CT multiscale imaging in lungs affected by COVID-19 pneumonia, we gained a new understanding how shunting between blood vessels in a lung’s two vascular systems occurs in Covid-19 injured lungs, and the impact it has on oxygen levels in our circulatory system."

X-Ray Homepage