Ultra-high resolution photon-counting CT with tin prefiltration for bone-metal interface visualization

Photon-Counting Computed Tomography: Experience in Musculoskeletal Imaging

“…Despite not being optimized for photon-counting data, iterative MAR has shown promise in PCCT for various types of implants, irrespective of the selected acquisition protocol [ 65 66 ]. However, with the current software, MAR postprocessing cannot be combined with a spatial frequency higher than 7.3 line pairs per centimeter at 50% of the modulation transfer function (Br56 kernel; Siemens Healthineers) [ 14 ], which is far from the image sharpness expected from UHR imaging.…”

“…As previously shown for a multitude of implants and metallic devices in EID-CT, the use of high-keV levels is especially effective for artifact reduction [ 16 ]. However, similar to iterative MAR, VMI cannot be combined with ultrasharp reconstruction kernels with a spatial frequency above 16.5 line pairs per cm at 50% of the modulation transfer function [ 14 ]. Although both VMI and MAR can be applied to a dataset synergistically, restricted image sharpness limits the number of use cases for this powerful artifact reduction tool ( Fig.…”

“…In musculoskeletal imaging, this development would certainly be welcomed with open arms. Although reconstruction sharpness remains a concern for MAR and VMI, especially in small bone and joint imaging [ 14 66 ], this problem may also be solved with future software updates. Whether PCCT scanners from other vendors will receive clinical approval in the near future remains a subject of speculation.…”

“…Postoperative imaging remains a challenging task for radiologists in every modality owing to characteristic artifacts usually being most pronounced in the area of interest, that is, adjacent to the bone-metal interface [ 14 ]. To diagnose or rule out implant failure, screw dislocation, or periprosthetic fractures, these anatomical areas must be visualized without significant image impairment.…”