Magneto acoustic tomography with short pulsed magnetic field for in-vivo imaging of magnetic iron oxide nanoparticles

Abstract

<p class="first" id="P1">Nanoparticles are widely used as contrast and therapeutic agents. As such, imaging modalities that can accurately estimate their distribution in-vivo are actively sought. We present here our method Magneto Acoustic Tomography (MAT), which uses magnetomotive force due to a short pulsed magnetic field to induce ultrasound in the magnetic nanoparticle labeled tissue and estimates an image of the distribution of the nanoparticles in-vivo with ultrasound imaging resolution. In this study, we image the distribution of superparamagnetic iron oxide nanoparticles (IONP) using MAT method. In-vivo imaging was performed on live, nude mice with IONP injected into lymph node derived cancer of the prostate tumors induced over the hind limb of the mice. Our experimental results indicate that the MAT method is capable of imaging the distribution of IONPs in-vivo. Therefore, MAT could become an imaging modality for high resolution reconstruction of MNP distribution in the body. </p><p id="P2"> <div class="figure-container so-text-align-c"> <img alt="" class="figure" src="/document_file/04bf949a-f53d-4d50-a7b1-3a1d714f3191/PubMedCentral/image/nihms742589f8.jpg"/> </div> </p><p id="P3">In magneto acoustic tomography a short pulsed magnetic field is applied to induce ultrasound in tissue labeled with magnetic nanoparticle through magneto motive force. Using ultrasound transducers placed around the object this ultrasound wave is measured. The reconstructed image from the ultrasound signal is a representation of the distribution of the magnetic nanoparticles in the tissue. This is shown in the present study with in-vivo experiments to detect and image the distribution of IONPs in live, nude mice with induced lymph node derived cancer of the prostate tumors over the hind limb. </p>