The objective of this chapter is to provide information about the advantages of direct conversion detectors (referred here as photon-counting detectors) for computed tomography (PCCTs) technology over traditional energy-integrated detectors (EIDs). We will discuss the clinical benefits of photon-counting detectors and their impact on preclinical and clinical practice. Given the unique capability of counting individual photons and discriminating its energy, photon-counting detectors offer unique benefits over conventional energy-integrating detectors. These include reduced electronic noise and radiation dose, increased contrast and contrast-to-noise ratio, reduced beam-hardening and metal artifacts, and simultaneous high-resolution and multi-energy imaging. These benefits have a broad impact on clinical CT exams in terms of image quality and radiation dose. The impact of PCCT technology on clinical CT exams is significant, providing improved image quality and reduced radiation dose. Certain benefits, such as the high resolution, will benefit specific exams and clinical areas more than the others. In addition to the improvement to the current clinical practice, there are also substantial opportunities for PCCT to enable new clinical applications, such as nanoparticles and multi-contrast imaging, that we will discuss at the end of this chapter.