Ultra-high-resolution CT of the temporal bone: Technical aspects, current applications and future directions
Fatma Boubaker, Michaël Eliezer, Guillaume Poillon, Helene Wurtz, Ulysse Puel, Alain Blum, Pierre Gillet, Pedro Augusto Gondim Teixeira, Cécile Parietti‐Winkler, Romain Gillet
Abstract
• Normal temporal bone anatomy is much better appreciated with ultra-high resolution CT techniques due to the 0.12-mm spatial resolution. • Ultra-high resolution CT with deep learning reconstruction is a promising technique for temporal bone imaging that outperforms conventional CT with at least 50 % dose reduction. • Pre- and postoperative imaging of otosclerosis has been improved owing to the use of ultra-high-resolution CT techniques. • Although conventional CT overestimates superior semicircular canal dehiscence, photon-counting detector CT allows more accurate measurement of bony dehiscence, which should benefit all types of third-window syndromes. Temporal bone imaging has historically suffered from spatial resolution issues because the spatial resolution of conventional high-resolution computed tomography (CT) is 0.5 mm, while the smallest structure of the middle ear, the stapes, has very thin components, as thin as 0.19 mm, and small structures, such as small channels containing nerves and arteries, have historically been beyond its spatial resolution. Photon-counting and ultra-high resolution CT allow for improved spatial resolution and reduced radiation dose compared to conventional high-resolution CT. This article provides a technical approach to understanding the technical aspects of these new techniques and an updated description of the middle and inner ear, as well as a practical approach to understanding the normal and pathologic anatomy of the temporal bone in the light of ultra-high resolution imaging techniques.