The U.S. FDA has cleared Siemens Healthineers’ Naeotom Alpha, the world’s first photon-counting CT. This is the first major technological innovation for CT in more than 10 years, that has been approved by the FDA. With a novel system concept and pioneering new detector technology, it ushers in a new era in computed tomography.

The centrepiece of this innovation is the new photon-counting detector whose active detection layer consists of a cadmium telluride one crystal (CdTe) and offers clear advantages over conventional CT detectors. Standard CT detectors convert the X-rays in a two-step process first into visible light that is subsequently detected by a light sensor, ultimately producing the final image. Due to this intermediate step, important information about the energy of the X-rays is lost and no longer available to aid in diagnosis; contrast is reduced, and images lack clarity. The photon-counting CT detector no longer converts the X-rays into visible light. The X-ray photons are converted directly into digital signals and then counted without information loss. This adds a wealth of completely new clinically relevant information and improves image sharpness and contrast.

Laurel Burk, Ph.D., assistant director of the Diagnostic X-ray Systems Team in the FDA’s Center for Devices and Radiological Health, said: “[The FDA approval] represents the first major new technology for computed tomography imaging in nearly a decade.” Siemens says they will release more information about Naeotom Alpha at their Shape 22 event in November.