Photon-counting detector CT delivered perfect sensitivity for colorectal liver metastases in an intra-patient diagnostic comparison, detecting 138 out of 138 reference lesions. The study contrasted photon-counting CT with conventional third-generation dual-source energy-integrating CT in 138 blinded reader evaluations. Across reader assessments, the conventional scanner identified 122 of 138 lesions, with pooled sensitivity falling to 88.4%, while photon-counting CT achieved 100% (95% CI 97.3–100%). Discordant readings favored the photon-counting approach. The practical implication is surgical planning accuracy: precisely characterizing lesion number, size, and segment location informs resection and ablation candidacy. That accuracy can reduce staging uncertainty and potentially improve treatment selection. While the results are compelling, translation to broad clinical adoption will depend on availability, workflow fit, and validation in larger multi-center cohorts.