In this report, we present a new noninvasive 3-dimensional (3D) imaging technology for in vivo monitoring of the skeletal development of mice: flat-panel volumetric Computed Tomography (fpvCT). Long-term investigations of 4 mice are presented, with up to 14 scans of each mouse from postnatal day 0 to 86. Examinations of a newborn and an adult mouse, performed with fpvCT and clinical multislice CT (MSCT), demonstrate the superior image quality of high-resolution fpvCT.