This study aims to develop a spatial model of bone for quantitative assessments of bone mineral density and microarchitecture. A spatially structured network model for bone microarchitecture was systematically investigated. Bone mineral-forming foci were distributed radially according to the cumulative normal distribution, and Voronoi tessellation was used to obtain edges representing bone mineral lattice. Methods to simulate X-ray images were developed. The network model recapitulated key features of real bone and contained spongy interior regions resembling trabecular bone that transitioned seamlessly to densely mineralized, compact cortical bone-like microarchitecture. Model-simulated imaging profiles were similar to patients' X-ray images. The morphometric metrics were concordant with microcomputed tomography results for real bone. Simulations comparing normal and diseased bone of 20-30 to 70-80 year-olds demonstrated the method's effectiveness for modeling osteoporosis. The novel spatial model may be useful for pharmacodynamic simulations of bone drugs and for modeling imaging data in clinical trials.