Researchers at the University of Wisconsin-Madison will begin scanning humans with GE Healthcare’s photon counting CT technology with deep silicon detectors in December 2022, making it the first U.S. clinical evaluation site for the scanner.

Photon-counting CT decreases pixel size and improves spatial resolution in images by converting individual X-ray photons into an electrical signal. It also has higher dose efficiency, allowing for ultrahigh-resolution images of large areas of the body to be captured. It offers the potential to visualize minute details in organ structures, improve tissue characterization, and provide more accurate material density measurements or quantification.

The solution’s silicon detectors are designed to enhance spatial and spectral resolution at the same time to improve imaging for oncology, cardiology, neurology, and other clinical CT applications.
Among the capabilities the researchers will examine are the scanner’s reconstruction methods, image presentation workflows, and clinical benefits for specific pathologies and disease types. They will use these insights to optimize photon counting CT with Deep Silicon detectors for better visualization and utilization.

UW-Madison’s research will provide GE with a better understanding of the potential and limits of these unique capabilities, said Dr. Meghan Lubner, professor of radiology at the UW School of Medicine and Public Health, in a statement.

“We are working with GE Healthcare by testing their novel photon counting solutions in human subjects to assess issues ranging from improving commonly encountered CT image quality limitations to evaluating whether previously out of reach clinical questions can now feasibly be answered,” she said in a statement.

Karolinska Institutet and MedTechLabs in Sweden performed the first clinical evaluation with the scanner in November 2021.

The new prototype at UW-Madison includes a larger detector that can possibly speed up scanning time and expand coverage; ECG-gated cardiac scan capabilities for coronary artery imaging; and faster acquisition speed for reducing the chance of blurred images due to motion.

In 2020, GE Healthcare acquired Prismatic Sensors AB, a Swedish startup specializing in silicon detectors for photon-counting CT. While silicon offers purity, abundance and broad manufacturing infrastructure to support photon counting CT detectors, it has historically been too thin to collect a sufficient number of X-ray photons.

GE Healthcare’s detectors are made of pure silicon and are placed “edge on” to manage the very high photon flux (quantity of information) from the CT’s X-ray tubes. They can absorb very high energy photons fast enough to count hundreds of millions of CT photons per second, creating crisper images.

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