Spectroscopic X-ray imaging now certified for medical use


CERN workshops on medical applications of spectroscopic X-ray detectors have helped advance spectroscopic X-ray imaging and bring it from the laboratory to the clinic

The sixth workshop on medical applications of spectroscopic X-ray detectors is currently taking place at CERN. Launched in 2011 and held every two years, this workshop brings together specialists from different fields to focus on how best to advance the efforts and understanding of this new imaging technique (also called “photon counting imaging”). , a technology that makes Color computed tomography possible). This year, more than 100 participants – clinicians, radiologists, medical physicists, biologists, tracer developers, imaging systems specialists and detector and ASIC developers – are taking part in the workshop. Their affiliations range from large medical equipment suppliers to start-ups and world-renowned research hospitals to small but active university groups.

“Eleven years ago there was great skepticism about the technical feasibility and clinical benefits of spectroscopic X-ray imaging,” says Michael Campbell, spokesperson for the Medipix collaborations at CERN. “CERN is the largest physics laboratory in the world, with state-of-the-art capabilities in microelectronics and particle detectors and a long history of global scientific collaboration, making it the ideal location for such a workshop. CERN workshops have helped to crystallize ideas and form a dynamic community of specialists convinced of the potential of technology.

And here they are today, celebrating a major milestone for the technology: the U.S. Food and Drug Administration (FDA) approval in 2021 of “the first major new technology enhancement for near-death CT imaging.” ‘a decade’ in the form of a photon counter scanner from Siemens. It is the first scanner using spectroscopic X-ray imaging officially approved for regular medical use in the world. “The CERN workshops have helped advance this technology and bring it from the lab to the clinic,” says keynote speaker Dushyant Sahani MD, professor and chair of the Department of Radiology at the University of Washington. “Spectroscopic X-ray imaging is poised to revolutionize diagnostic medical imaging by providing better images with lower patient dose, enabling new workflows that optimize valuable hospital resources.”

Even closer to CERN, MARS Bioimaging’s 3D color X-ray wrist scanner is awaiting approval to start clinical trials at the Lausanne University Hospital (CHUV, Switzerland) and is undergoing ongoing clinical trials at within the Pacific Radiology Group, New Zealand’s largest provider of radiology services. . CERN and the New Zealand company MARS Bioimaging joined forces in 2008 to develop this 3D color X-ray scanner based on Medipix3 technology.

“Much of the technology that makes spectroscopic X-ray imaging possible comes from fundamental research and, in particular, from R&D on detectors for high-energy physics experiments,” explains Giovanni Anelli, head of the CERN Knowledge Transfer group. “CERN has a proactive knowledge transfer policy and I am proud of the role that Medipix project participants and our commercial partners have played in high resolution spectroscopic X-ray imaging.”

Why are spectroscopic X-ray detectors such a revolutionary technology?

X-ray beams used in medical equipment contain a wide spectrum of X-ray energies, which can be thought of as different colors of X-rays. In conventional detectors, the image taken is based on the total energy of the X-rays X absorbed by each pixel, forming a kind of black and white image. When spectroscopic detectors are used, the images also contain the “colors” of incoming X-rays, providing better and clearer images at optimized doses with significant benefits when diagnosing disease. Under certain circumstances, MRI (magnetic resonance imaging) may even become superfluous. In other cases, where metal contrast agents attached to biomarkers are injected into the body, costly PET-CT (positron emission tomography – computed tomography) scans can be avoided.

The concept of utilizing X-ray energy information was first applied in so-called dual-energy computed tomography (DECT) systems. In these systems, two images are taken one after the other at different x-ray tube voltages (kVp). As each image has a different average X-ray energy, these could be combined to produce clearer images compared to single images. However, the decision to use DECT imaging must be made before the patient is scanned, and DECT is only used when necessary, as the patient normally receives a higher dose of radiation.

Spectroscopic detectors, on the other hand, provide much more information than DECT systems. Only one image is taken. No prior decision is necessary and no additional dose is used: the energy information is always available.

If you are interested in a summary of the 2022 workshop, tune in to the webcast of the presentation by Anthony Butler (MARS Bioimaging) on ​​Friday 2September at 11:00 a.m. CET. Recording will be available later.


For more information on the workshop or Medipix collaborations, contact Michael Campbell at [email protected]


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