Key Visual Siemens Healthineers Quantum Technology showirng the face of a middle-aged women, next to the abstract visualization of a photon-counting detector with its precise pulses

Photon-counting CT

A quantum leap in computed tomography

Quantum Technology® is transforming CT by introducing photon-counting technology into clinical routine. At its core is the QuantaMax® detector, which is equipped with a crystal semiconductor that is substantially different from a standard scintillation detector. QuantaMax detectors create CT images at high spatial resolution, without electronic noise, and with an improved contrast‐to‐noise ratio, intrinsic spectral information, and at a lower radiation dose.

The purest cadmium telluride crystal is the starting point for a quantum leap in computed tomography technology. Years of research, development, and production have led to the generation of pure crystals with electrical properties that have revolutionized CT detector technology. Take a sneak peek into our crystal-growing lab, where the combination of innovation and craftsmanship is worth every effort.

Improved detector efficiency with direct signal conversion

The crystal semi-conductor in the QuantaMax detector enables direct signal conversion by generating an electrical charge instead of light. Each of the tens of thousands of X-ray photons is individually measured in a single projection. The absorbed X‐rays create electron‐hole pairs in the semiconductor. The charges are separated in a strong electric field between the cathode on top of, and the pixelated anode electrodes at the bottom of the detector. This improves detector efficiency without a dose penalty as it does not require septa dividing the detector into pixels.

  • Smaller detector pixels
  • Elimination of noise
  • Intrinsic spectral sensitivity
  • Equal contribution of lower energy quanta

Designed with the smallest pixels ever used in a whole-body CT, Quantum Technology can deliver ultra-high-resolution images at full dose efficiency.

As photon-counting detectors directly convert X-rays into electric charges which are not subject to decay and afterglow, this technology allows a clear distinction between signal and electronic noise – allowing the elimination of the latter.

Measuring discrete photon energy levels in up to four energy bins means that the spectral information is captured for every exam.

There is no down-weighting of low-energy photons in photon-counting detectors because each X-ray’s energy is measured, resulting in optimum image contrast and an increased iodine contrast-to-noise ratio.

Discover the full potential of NAEOTOM Alpha photon-counting CT.