A review of applications of photon-counting computed tomography in head and neck imaging

Photon-counting CT (PCCT), approved for clinical practice for over 2 years now, both improves on features of conventional energy-integrating detector (EID)-CT and introduces new capabilities such as multienergy acquisition. PCCT is already transforming all domains of radiology, including head and neck imaging, and will become increasingly utilized in the approaching years. In this review, we first concisely explain the key physical principles distinguishing PCCT from EID-CT. We then discuss how the underlying physics leads to the novel features associated with PCCT, focusing on improved artefact reduction, spatial resolution, contrast-to-noise ratio, as well as multienergy acquisition and reduced contrast and radiation doses. Next, we review head and neck PCCT applications and comparison to EID-CT in dental imaging, sinus imaging, temporal bone, tumour imaging, and vascular imaging. Within the temporal bone applications, we explore normal anatomy, pathologic anatomy, and the appearance of prostheses and implants. Representative imaging is provided to highlight differences between PCCT and EID-CT. Finally, we highlight areas of ongoing research in PCCT.