Evidence that SPIO Chain Formation is Essential for High-Resolution MPI

作者：Caylin Colson, KL Barry Fung, Jacob Bryan, Zhi Wei Tay, Benjamin Fellows, Chinmoy Saayuja, Renesmee Kuo, Prashant Chandrasekharan, Steven Conolly · 发表于：bioRxiv (Cold Spring Harbor Laboratory) · 年份：2022 · DOI：10.1101/2022.11.27.518061 · 被引用次数：5 · 研究领域：Characterization and Applications of Magnetic Nanoparticles、Geomagnetism and Paleomagnetism Studies、Magnetic properties of thin films

Abstract Magnetic Particle Imaging (MPI) is a noninvasive imaging modality that exploits the saturation properties of superparamagnetic iron oxide particles (SPIOs). A major thrust of MPI research aims to sharpen the magnetic resolution of biocompatible SPIOs, which will be crucial for affordable and safe clinical translation. We recently reported on a new class of MPI tracers —called superferromagnetic iron oxide nanoparticles (SFMIOs) — which offer much sharper magnetic saturation curves. SFMIOs experimentally demonstrate 10-fold improvement in both resolution and sensitivity. However, superferromagnetism is a relatively unexplored branch of physics and the nanoscale physics and dynamics of SFMIOs remain a mystery. Here we show experimentally that chaining of SPIOs can explain SFMIO’s boost in SNR and resolution. We show how concentration, viscosity, transmit amplitude, and pre-polarization time can all affect SPIO chain formation and SFMIO behavior. These experiments will inform strategies on SFMIO chemical synthesis as well as SFMIO data acquisition pulse sequences.