Gd-based nanoparticles mediated magnetic field enhancement inside homogenous tissue: Simulation using finite element method

Abstract

Tumor detection in the early stages is of outmost importance in cancer diagnosis and treatment. Magnetic resonance molecular imaging (MRMI) is a considerable medical imaging method to distinguish normal cells from cancerous cells initiating metastasis. Current MRI contrast agents are required to prevent adverse chemical activity in the body. Therefore, in conventional form of Gd-DTPA due to their relatively large size and coverage can be used only in extracellular spaces. Meanwhile, nanoparticles, because of their small size relative to the body cells, are capable of intrusion inside the cells. These materials can be used for molecular imaging; Gd-based paramagnetic nanoparticles are the most widely used agents. In this paper, variation in external magnetic field as a result of using Gd-based nanoparticles in homogenous tissue was investigated with finite element method. To this end, simulations have been carried out in the presence of Gd nanoparticles and without them. This study indicated that magnitude of external magnetic field increases due to the presence of nanoparticles, and we compared the results with Vibrating Sample Magnetometer (VSM) results. In addition, Gd nanoparticles showed sigmoidal (superparamagnetic) behavior in both data set of simulation and VSM, applicable to normal cell uptake and so tumor cell tracking for cancer detection.