Radiolabeled Iron Oxide Nanomaterials for Multimodal Nuclear Imaging and Positive Contrast Magnetic Resonance Imaging (MRI): A Review

Abstract

Iron oxide nanoparticles (IONP) have been hailed as potential game-changers in biomedical imaging owing to their biocompatibility and size-dependent properties. One area where IONP has shown particular promise is magnetic resonance imaging (MRI), which traditionally uses superparamagnetic nanomaterials to produce negative contrast that darkens the tissues where nanoparticles accumulates. Unfortunately, this hypointense signal is a major drawback for clinical applications because it can make it difficult to identify the accumulated probes. As a result, researchers are exploring alternative options that can incorporate the advantages of IONP while also possessing valuable properties for molecular imaging. To achieve this goal, the most effective method involves not only utilizing positive contrast in MRI applications but also combining IONP with the unparalleled sensitivity of nuclear imaging techniques, for example, using radioisotopes to create PET/(T 1)­MRI multimodal probes. To create such probes, various factors must be considered, including the radiolabeling strategy employed and overall complexity of the final nanoprobe. These nanoradiomaterials offer novel possibilities that span beyond the molecular imaging field, showing potential for the development of radiopharmaceuticals and theranostics.

Enhancing MRI through high loading of superparamagnetic nanogels with high sensitivity to the tumor environment

“…This classication is based on their ability to reduce the signal intensity in T 2 -weighted images, resulting in Paper Nanoscale Advances darker areas or negative contrast. 10,47 Fig. 5B shows the results of signal intensities which were quantitatively analyzed using region of interest (ROI) within the tumor area.…”

Gamma-Camera Direct Imaging of the Plasma and On/Intra Cellular Distribution of the 99mTc-DPD-Fe3O4 Dual-Modality Contrast Agent in Peripheral Human Blood

“…For example, among the advantages of these techniques are the high sensitivity of nuclear imaging, namely SPECT (or PET) and the high spatial resolution of MRI [1][2][3][4]. To this effect, many studies [5][6][7][8][9][10][11] have highlighted the enhanced diagnostic efficacy of SPECT (or PET)/MRI DMCAs compared to conventional contrast agents. In everyday clinical practice, radionuclides are used extensively up to now in the form of radiopharmaceuticals both for diagnostic and for therapeutic purposes.…”