The high demand for ultralow detection limits of ionizing radiation in aerospace radiographic testing, medical radiography, high-energy physics, and security screening has driven extensive research on X-ray imaging scintillators. While high-performance scintillators in the current X-ray imaging market made of ceramics that require harsh and costly preparation and engineering conditions, perovskites and their related structures, heavy-atom engineered thermally activated delayed fluorescence (TADF) and copper nanoclusters with their unique optical behaviors and high X-ray absorption cross section are now promising competitors if not alternatives. In this talk, I will present the engineering of perovskite nanosheets with excellent scintillation performance due to efficient energy transfer processes between stacked thin and thick nanosheet. Additionally, I will talk about the efficient and ultrafast energy transfer strategies between perovskite nanosheets and TADF that successfully  produced a reabsorption-free organic X-ray imaging scintillator with an ultralow detection limits and outstanding X-ray imaging resolution. Similarly, I will talk about perovskite related Cu and Ag halides as well as Cu-based halide nanostructures that showed outstanding X-ray imaging performance.⁷ Moreover, we will discuss the fabrication of a thick pixelated needle-like array scintillator capable of micrometer resolution via waveguide structure engineering that lead to ultra-high spatial resolutions of 60.8 lp mm^-1, representing a laboratory-scale record for extensively studied metal halide scintillators. The talk also discusses a novel top-filter-bottom sandwich structure scintillator for high-performance dual-energy X-ray imaging within a single exposure. Finally, our innovation  of true-color multi-energy X-ray imaging technology centered around multiple scintillator architecture with a six-layer ∆E-E telescope configuration to achieve powerful material-specific capability, surpassing what is offered by traditional X-ray imaging technologies will also be discussed in this talk. This breakthrough research enables clear resolution of different biological tissues and materials objects based on their corresponding colors and paves the way for the development of new imaging scintillator architectures with potential applications in medical imaging, industrial monitoring and security checks.