摘要 磁共振成像技术被广泛应用于诊断医学和软组织成像, 而磁共振对比剂有助于提高成像对比度. 报道了两种基 Abstract Magnetic resonance imaging (MRI) is widely used in diagnostic medicine and soft tissue imaging. Contrast agents (CAs) can improve the specificity of MRI enhancement. Herein, the design, synthesis and relaxivity of two novel binuclear nonionic Gd-based DOTA-hydrazide derived MRI contrast agents, (Gd-DOTAH) 2 -DYMB and (Gd-DOTAH) 2 -DYMBP are reported. They have improved longitudinal relaxivity values of 11.4 and 11.7 L•mmol -1 •s -1 per molecule or 5.7 and 5.9 L•mmol -1 •Gd -1 •s -1 at 0.5 T, respectively, which are higher than that of the mononuclear clinical macrocyclic agent Gd-DOTA. And in vitro MRI studies suggest the potential of these two agents as MRI contrast agents in improving the diagnostic sensitivity and accuracy.