Researchers at the Technical University in Garching (TUM) have developed a novel X-ray method for lung diagnostics, which they now want to test in one of the first applications for the diagnosis of the lung disease Covid-19 caused by the coronavirus.
Garching - According to the press release, the procedure could make the changes in the lungs typical of the disease clearly visible and would be associated with a considerably lower radiation dose than the computed tomography (CT) currently used. The Federal Office for Radiation Protection has given the necessary approval for the tests.
Cooperation with Klinikum rechts der Isar
With the help of the new procedure, many patients could be examined in a short time and the results would be available immediately after the examination. In collaboration with the University Hospital right of the Isar, Franz Pfeiffer, professor of biomedical physics and director of the Munich School of BioEngineering at TUM, wants to test the new X-ray method of so-called dark field imaging for the diagnosis of Covid-19.
Dark field image makes damaged alveoli visible
The new method uses the physical phenomenon of scattering in a similar way to the well-known dark field microscopy with visible light. This makes it possible to clearly depict largely transparent objects that appear in the microscope as bright structures against a dark background. “The scatter is particularly strong at the interfaces between air and tissue, for example,” explains Pfeiffer. This made it possible to clearly distinguish areas with intact, i.e. air-filled, alveoli in a dark field image of the lungs from regions in which the alveoli have collapsed or are filled with fluid. In pneumonia, such as that caused by Covid-19, structures form in the lungs that initially resemble cotton or cobwebs in shape and increasingly spread in the lungs and fill with fluid. In conjunction with other typical symptoms, they are considered a clear sign of Covid 19 disease. The changes in the lungs are accompanied by damage to the alveoli, which could be clearly seen in the dark field images.
Fundamentally new investigation method
Dark field imaging with X-rays is a completely new examination method for medicine, which Franz Pfeiffer and his team have developed in over ten years. In 2008, he introduced the basic approach that makes it possible to use conventional X-ray tubes, such as those used in medical practices. Until then, the process could only be used with high-quality X-ray light, which is only available in complex large-scale research facilities. Since the first laboratory tests, he has developed the method together with employees and in close cooperation with doctors so that a device suitable for patient examinations is now available.
Significantly lower radiation dose
An investigation using the dark field technique would involve a significantly lower radiation dose than the computed tomography used today. This is because it only requires one single exposure per patient, while numerous individual images from different directions have to be created for computer tomography.
With the approval of the Federal Office for Radiation Protection now available, the tests started this week. To this end, the researchers want to offer patients who are being examined at the Klinikum rechts der Isar with computed tomography on Covid-19 to be examined using the dark field method. They want to confirm that the disease can actually be diagnosed reliably in this way.
Marketable devices available at the earliest in one year
Franz Pfeiffer hopes that these tests will accelerate the conduct of clinical studies and the development of marketable devices that use the dark field method. “It would surely take over a year for such devices to be available. However, we can assume that the need for cost-effective, reliable and gentle Covid-19 diagnostics will remain for a long time, ”emphasizes Pfeiffer.
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