The Modeling of Magnetic Detection of Iron Oxide Nanoparticles in the Stream of Patient-Specific Coronary Artery with Stenotic Lesion: the Effects of Vessel Geometry and Particle Concentration

Abstract

Magnetic nanoparticles (MNPs) prepared as a stable colloidal suspension dispersed in water have attracted special interest for different applications in theranostics [1]. MNPs of maghemite obtained by a laser target evaporation (LTE) were shown to be excellent candidates for this purpose [2]. Magnetic suspension flowing through the blood vessel creates magnetic fields which can be detected by giant magnetoimpedance magnetic field sensor (GMI) [3]. In this work, we develop a computer model for calculation of the distribution of blood flow velocity V and magnetic fields H in the area of a blood vessel with stenosis. Finite element model (FEM) is used to analyze the properties of the model system reconstructed from the image obtained during routine examination of a patient using angiography.Figures show selected results of the studies. It was shown that the relative change of the magnetic field strength in the area inside the blood vessel doesn’t depend on the value of the external magnetic field He and the value of additional magnetic field connected to the blood flow is proportional to the concentration of MNPs. To describe the results obtained for a model of a real vessel, a model of a vessel in the form of a cylinder with different radius of curvature and thickness was studied. The results of calculations the flow of MNPs in the vessel showed that at 1.5 wt % of MNPs concentration (c=1.5 wt %) the relative change in the magnetic field in the area of stenosis is 0.43%, and in the area before stenosis is 0.33%. According to experimental data, the observed difference in the distribution of magnetic fields at a concentration of LTE MNPs from 0 to 2% can be measured using a thin-film detector of small magnetic fields GMI.This study was supported by the Ministry of Science and Higher Education of the Russian Federation (project No. FEUZ -2020-0051).  Fig.1. Velocity distribution in a blood vessel with stenosis. The inset shows the value along the cross-section indicated by horizontal red line.  Fig.2. Magnetic field (H) distribution in a blood vessel with stenosis. The inset shows the value along the cross-section indicated by horizontal red line. He = 5 Oe and is directed from left to right, c=1.5 wt %.