Magnetic resonance imaging (MRI) is one of the most powerful molecular imaging techniques and can noninvasively visualize and quantify biological processes within the living organisms. The introduction of exogenous contrast agents has allowed specific visualization of biological targets as well as enhanced the sensitivity of MRI. Recently, paramagnetic inorganic nanoparticles showing positive T1 contrast effect have been investigated as T1 MRI contrast agents. Since the first trials of spherical nanoparticles of manganese oxide and gadolinium oxide, inorganic nanoparticles of various compositions and shapes have been used for in vivo and in vitro MRI because of their distinct signal enhancement in MR images. However, for clinical applications, important and complex issues such as safety and efficiency should be investigated by active research encompassing multiple disciplines, including chemistry, biology, biomedical engineering, and medicine.
For further resources related to this article, please visit the WIREs website.
Conflict of interest: The authors have declared no conflicts of interest for this article.