Until recently, the use of dark-field X-rays had been studied in small animals and cadavers, but never humans. That is until researchers at the Technical University of Munich (TUM) put the technology to the test with patients. They discovered that dark-field imaging can be a valuable and cost-effective tool in the early diagnosis of respiratory diseases.
For the study, researchers at TUM designed and constructed a novel dark-field chest X-ray system capable of producing typical thorax radiographs, focusing on the early detection of emphysema in patients with COPD. A total of 77 patients who had undergone medically indicated chest CTs were recruited. Those with conditions other than COPD that might influence lung parenchyma were excluded. Five separate readers obtained and reviewed chest CTs and dark-field X-rays for all patients.
Compared to the CT scans, the dark-field signal yielded a stronger correlation with lung diffusion capacity. In addition, the dark-field emphysema assessment was consistent with the results of the CT scans, but without the increased radiation dose CT imaging requires. In fact, the radiation dose of dark-field imaging could be reduced by a factor of fifty, according to the study.
"The X-ray dark-field signal is particularly strong for interfaces between air and tissue. This makes it possible for a dark-field X-ray image of the lung to clearly distinguish between intact alveoli, i.e. those filled with air, and regions in which less intact alveoli exist," explained Franz Pfeiffer, professor of Biomedical Physics and director of the Munich Institute of Biomedical Engineering at TUM, who lead the team of researchers.
Since conventional chest X-rays might not be sensitive enough to detect early pulmonary changes and CT scans come at a much higher financial cost and with significant increases in exposure to radiation, dark-field imaging might help to bridge the gap and benefit both patients and providers, experts imply.
You can read the detailed study in the November issue of The Lancet Digital Health.
In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She joined Innovate Healthcare in 2021 and has since put her unique expertise to use in her editorial role with Health Imaging.