A detailed analysis of the effects of temperature changes, over time and between array elements, on the generation of circular artifacts in images produced by x-ray computed tomography was reported. We give formulas for calculating--according to the x-ray energy, detector sensitivity, and observed image quality (contrast and spatial resolution)--the maximum offset temperature coefficient and maximum gain temperature coefficient that will allow circular-artifact-free imaging. A temperature-controlled and insulated solid-state x-ray detector array, consisting of Gd2O2S:Pr,Ce,F ceramic scintillators coupled to crystal Si pin-photodiodes and designed to meet the requirements for these coefficients, produced high-resolution artifacts-free CT images of a phantom head.