A new technology called photon-counting CT has the potential to significantly alter clinical CT. The novel energy-resolving x-ray detectors used in photon-counting CT have mechanisms very different from traditional energy-integrating detectors. CT detectors that count incoming photons and quantify photon energy are known as photon-counting detectors. Increased contrast-to-noise ratio, enhanced spatial resolution, and optimal spectrum imaging are the outcomes of this approach. Compared to existing CT technology, photon-counting CT can minimize radiation exposure, improve the reconstruction of images at a higher resolution, eliminate beam-hardening artifacts, maximize the use of contrast agents, and open new possibilities for quantitative imaging. After providing an outline of the state of photon-counting CT as of right now, they will describe.