2025, Vol. 8, Issue 4, Part A

Photon-counting CT is an emerging technology with the potential to change clinical CT.Conventional detectors measure X-rays by converting them into visible light and then collecting the emitted visible light per pixel with aphotodiode. Dose usage limitations constrain high-resolution imaging with scintillator-based detectors. In low-dose applications, classical electronic noise becomes a significant issue. Additionally, true material separation within the scanned object can only be achieved if dual-energy protocols are selected before the scan. Photon counting detectors constructed from semiconductor crystals enable the individual detection of incoming photons through a direct conversion process this technique results in higher contrast-to-noise ratio, improved spatial resolution, and optimized spectral imaging.

This review will evaluate the principle of photon-counting CT, its potential, and the variety of clinical applications of photon-counting detector technology along with its limitations.