Influence of phantom design on evaluation metrics in photon counting spectral head CT: a simulation study

These findings underscore the critical importance of phantom design, especially the inclusion of skull-mimicking materials, in the assessment of quantitative results. Cylindrical phantoms, commonly used for calibration and testing, may overestimate performance in iodine quantification for head CT due to their simplified geometry. We emphasize the need for adopting anatomically realistic phantom designs, such as elliptical phantoms with skull simulants, to enable a more clinically relevant and accurate evaluation of spectral photon-counting head CT systems.