Characterization of magnetic nanoparticles as image contrast by ultrasound

• Grant number: 23/05357-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2023
• End date: August 31, 2025
• Field of knowledge: Engineering - Biomedical Engineering - Medical Engineering
• Principal Investigator: Antonio Adilton Oliveira Carneiro
• Grantee: Marina Yuki Azevedo Nakakubo
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 18/16939-8 - Development and implementation of novel acoustic, magnetic and optical techniques for diagnostic and therapeutic applications, AP.TEM

Abstract

The use of magnetic particles as markers in ultrasound images has been proposed as a new opportunity to support clinical diagnosis, with the ability to obtain molecular information. This technique, called magnetoacoustography, consists of mechanically exciting a target or medium marked with magnetic nanoparticles through the application of an alternating magnetic field and measuring the displacement of internal structures through a pulse-echo ultrasound transducer (Bruno 2015; Mehrmohammadi et al., 2011). The amplitude and phase of the displacement of these magnetic nanoparticles are related to the their magnetic properties and the viscoelastic properties of the medium. With the objective of investigating this dependence, a study of the amplitude and phase between the oscillating magnetic field and the displacement promoted by the internal structure of the tissue labeled with nanoparticles is being proposed in this project. This displacement, which is in the order of a micrometer, will be acquired using pulse-echo ultrasound measurement during the application of an oscillating magnetic field. The nanoparticles will be developed and coated with different materials in our own laboratory and also acquired from collaborators. The experimental protocol will consist of the application of an alternating magnetic field, ranging from 10 - 200 HZ, with intensity between 0.3T and 1 T. Using a high sampling rate ultrasound, with a linear matrix transducer, the echo maps will be obtained of the internal structures of the medium marked with the nanoparticles. The displacement map will be obtained using windowed cross-correlation between pairs of consecutive echoes (Neves et al. 2007). This study will consist of the following steps: a) Explore different amplitudes of magnetic fields and excitation frequencies. b) prepare mimicking samples of biological tissues marked with magnetic nanoparticles; c) Explore the contrast of the images generated by the location of these nanoparticles; d) Apply the study to different types of magnetic nanoparticles.