This study assesses the accuracy of medical X-ray computed tomography (CT) for estimating volumetric ice content in permafrost samples. Comparison of 261 cores from northern Canada shows that medical CT systematically underestimates ice in sediment-rich samples and overestimates it in organic-rich ones due to resolution limits and material misclassification. The results highlight medical CT's value for visualizing cryostructures but its limits for quantitative ice estimation.