上转换发光纳米颗粒是一类遵循反斯托克斯原理的新型发光材料, 具有发光强度高、发光稳定、无组织背景荧光、无光漂白、低毒性以及较好的生物相容性等优点, 其激发光为红外或者近红外光, 活体组织穿透深度高, 在生物医学检测、诊断以及疾病治疗等方面均具有潜在的应用价值。磁共振成像是目前医学临床常用的影像检测手段之一, 具有软组织成像质量高、空间分辨率高、无辐射、无损伤等优点, 在心脑血管、肿瘤等疾病的影像诊断方面具有重要作用。本文将聚焦于近年来稀土上转换发光纳米材料在磁共振影像方面的研究进展, 通过介绍磁共振成像机理、磁共振造影剂的构建、上转换发光纳米材料的设计及在磁共振医学影像、疾病治疗等方面的应用, 并结合我们课题组基于UCNP医学磁共振多模态影像的相关研究进展, 对上转换发光纳米颗粒在磁共振成像方面的应用研究进行探讨和展望。

Upconversion nanoparticle (UCNP) following anti-Stokes principle is a novel type of luminescence materials, which possesses many unique merits such as high luminescence intensity, luminous stability, no background fluorescence, no bleaching, low toxicity and good biocompatibility. The infrared or near infrared excitation light endows UCNP with deep penetration in living tissues for potential applications in biomedical detection, diagnose and treatment. Magnetic resonance imaging (MRI), as one of the commonly used techniques in clinical, has many special advantages like high quality of soft tissue imaging, high spatial resolution, no radiation and no damage, which plays a significant role in diagnosis of cardiovascular and cerebrovascular diseases. In this review, we focus on the recent researches in regard to rare-earth upconversion nanomaterials for MRI diagnosis and application. The mechanism of magnetic resonance imaging, the construction of MRI contrast agents, and the design and synthesis of UCNP-based multi-functional nanomaterials for MRI diagnosis and disease therapy have been introduced in detail, on the other hand, by means of the relevant researches reported by our group, which are based on UCNP for medical MRI and multimodal imaging, the prospects of UCNP in the application of MRI have also been discussed in this review.