Photon-counting CT offers the potential to provide new diagnostic information. In this study, we sought to determine the interplay between material identification errors, image quality indicators, and radiation doses using photon-counting spectral CT, and to determine whether this relationship is replicated in spectral CT scans of mice. Custom-built Perspex phantoms were used to measure signal-to-noise ratio (SNR) and spatial resolution, and to measure radiation dose using thermoluminescent dosimeters. A multicontrast calibration phantom containing inserts with different concentrations of gadolinium (1, 2, 4, and 8 mg/mL), hydroxyapatite rods (0, 54.3, 104.3, 211.7, 402.3, and 808.5 mg/mL) along with water and lipid was used to assess material identification errors. Image acquisition was performed using the MARS photon-counting scanner with four energy channels (30-45, 45-60, 60-78, and 78-118 keV) at four different tube currents (24, 34, 44, and 55 µA). As increased tube current showed no significant effect on material characterization,