This review article by Jianjun Lai, Zhizeng Luo, Liting Chen, and Zhibing Wu provides an overview of the advancements in nanotechnology-based targeted-contrast agents for computed tomography (CT) and magnetic resonance (MR) imaging. The authors highlight the limitations of traditional contrast agents and emphasize the importance of developing targeted nano-contrast agents to improve diagnostic accuracy and early disease detection. The review covers the preparation methods and research advancements in CT nano-contrast agents, MR nano-contrast agents, and multimodal CT/MR nano-contrast agents. Key topics include the physicochemical properties of nanomaterials, such as self-assembly and surface modifiability, which enhance the targeting of lesions and improve image resolution. The article also discusses specific examples of nano-contrast agents, including iodine, gold, and manganese-based agents, and their applications in CT and MRI. Additionally, the authors explore the development of multifunctional nano-contrast agents that can provide simultaneous multimodal imaging, enhancing diagnostic efficiency and reducing patient pain and treatment costs. The review concludes by emphasizing the potential of nano-contrast agents in improving medical imaging and their future research directions, while acknowledging the challenges related to biotoxicity and pharmacokinetic evaluation.This review article by Jianjun Lai, Zhizeng Luo, Liting Chen, and Zhibing Wu provides an overview of the advancements in nanotechnology-based targeted-contrast agents for computed tomography (CT) and magnetic resonance (MR) imaging. The authors highlight the limitations of traditional contrast agents and emphasize the importance of developing targeted nano-contrast agents to improve diagnostic accuracy and early disease detection. The review covers the preparation methods and research advancements in CT nano-contrast agents, MR nano-contrast agents, and multimodal CT/MR nano-contrast agents. Key topics include the physicochemical properties of nanomaterials, such as self-assembly and surface modifiability, which enhance the targeting of lesions and improve image resolution. The article also discusses specific examples of nano-contrast agents, including iodine, gold, and manganese-based agents, and their applications in CT and MRI. Additionally, the authors explore the development of multifunctional nano-contrast agents that can provide simultaneous multimodal imaging, enhancing diagnostic efficiency and reducing patient pain and treatment costs. The review concludes by emphasizing the potential of nano-contrast agents in improving medical imaging and their future research directions, while acknowledging the challenges related to biotoxicity and pharmacokinetic evaluation.