Inorganic Nanoparticles for MRI Contrast Agents

Abstract

Various inorganic nanoparticles have been used as magnetic resonance imaging (MRI) contrast agents due to their unique properties, such as large surface area and efficient contrasting effect. Since the first use of superparamagnetic iron oxide (SPIO) as a liver contrast agent, nanoparticulate MRI contrast agents have attracted a lot of attention. Magnetic iron oxide nanoparticles have been extensively used as MRI contrast agents due to their ability to shorten T2* relaxation times in the liver, spleen, and bone marrow. More recently, uniform ferrite nanoparticles with high crystallinity have been successfully employed as new T2 MRI contrast agents with improved relaxation properties. Iron oxide nanoparticles functionalized with targeting agents have been used for targeted imaging via the site‐specific accumulation of nanoparticles at the targets of interest. Recently, extensive research has been conducted to develop nanoparticle‐based T1 contrast agents to overcome the drawbacks of iron oxide nanoparticle‐based negative T2 contrast agents. In this report, we summarize the recent progress in inorganic nanoparticle‐based MRI contrast agents.

Influence of annealing temperature on structural and magnetic properties of MnFe2O4 nanoparticles

“…They have wide applications, ranging from fundamental research to industrial applications. The possible applications of manganese ferrite nanoparticles are in magnetic storage, as precursors for ferrofl uids, contrast-enhancing agents in magnetic resonance imaging (MRI), effi cient catalyst for degradation of dye pollutants and magnetically guided drug-delivery agents [4][5][6].…”

Synthesis of Eu3+-doped Gd2O3 in hollow nanoparticle structures by controlled chemical etching with poly(acrylic acid)

“…However, T 2 contrast agent can cause the confusion in the clinical usage due to the dark signal induced by the negative enhancement of T 2 contrast agent which is similar to other pathogenic conditions. 11 Due to this reason, T 1 agent is more suitable than T 2 agent for the usage as a contrasting agent and several gadolinium complexes have already been widely used. [8][9][10] Optical Characterization.…”

Functionalized nanomaterials: their use as contrast agents in bioimaging: mono- and multimodal approaches

“…The efficiency of iron oxide probes as T 2 CA is sizedependent and increases with higher particle crystallinity [26,79,86,96,97] . However, these NPs, generally synthesized at low temperatures, have poor crystallinity associated with small size and lack of monodispersity, as also found for the other nanomaterials [98] .…”