Marking the first clearance in nearly a decade for any significant advancement in CT, the FDA has given the nod to Siemens' photon-counting scanner NAEOTOM Alpha.

Unlike conventional CT scanners, which uses detectors to measure total energy contained in many X-rays at one time, photon-counting detectors measure each individual X-ray that passes through a patient’s body. By "counting" each individual X-ray photon, the scanner can collect more detailed information about the patient. It can then form images that reflect the most useful information to help clinicians make better decisions around diagnosis and treatment, and personalize care.

NAEOTOM Alpha is designed to use photon-counting to produce detailed 3D images. The images can be used to train physicians in diagnosing patients and by staff to make diagnoses, prepare treatment, and in radiation therapy planning.
“Today’s action represents the first major new technology for computed tomography imaging in nearly a decade and underscores the FDA’s efforts to encourage innovation in areas of scientific and diagnostic progress,” Laurel Burk, assistant director of the diagnostic X-ray systems team in the FDA’s Center for Devices and Radiological Health, said in a statement.

In addition to collecting more information on patients, photon-counting’s higher contrast-to-noise ratio enhances image resolution and quality, while reducing dose exposure, and corrects artifacts. It also creates access to quantitative imaging capabilities, which provides more numerical data on tumors and signs of cancer for more personalized care.

That’s why Canon recently teamed up with the National Cancer Center Japan and EAST Hospital in Kashiwa to research the use of photon-counting CT. Together, they will use the its quantitative capabilities to assess treatment effects from chemotherapeutic agents on malignant tumors and analyze different tissue characteristics for clinical insights in a wide range of medical fields.

Mayo Clinic in Rochester, Minnesota also recently used it for the first time in cardiac scanning as part of a collaboration with Siemens Healthineers. The technology is fast enough to provide clear images of the heart and blood vessels and can capture a small fraction of one heartbeat by "freezing" the motion.

For Mayo, this was a third-generation research system incorporating the technology. The first photon-counting detector CT system there and in the world was installed in 2014, with the first research studies in humans beginning in August 2015. A second-generation prototype was installed in 2020 and addressed many of the design limitations of the first, including a 20% reduction in slice thickness, a greater field of view, better data handling speeds and the ability to perform image reconstruction online. The third now offers cardiac gating capabilities.

Massachusetts General Hospital also just incorporated photon-counting in a new research pilot program in NeuroLogica’s OmniTom Elite CT with Photon Counting Detector technology. The technology will be used in ICU settings to help diagnose patients at the point-of-care, while limiting the need for extra transport.

Siemens NAEOTOM Alpha was evaluated on the 510(k) premarket clearance pathway.

CT Homepage