Developing magnetorelaxometry imaging for human applications.

Magnetic nanoparticles (MNPs) are a promising tool in biomedical applications such as cancer therapy and diagnosis, where localization and quantification of MNP distributions are often mandatory. This can be obtained by magnetorelaxometry imaging (MRXI).In this work, the capability of MRXI for quantitative imaging of MNP inside larger volumes such as a human head is investigated. We developed a human head phantom simulating a glioblastoma multiforme (GBM) tumor containing MNP for magnetic hyperthermia treatment. The sensitivity of our MRXI setup for detection of MNP concentrations in the range of 3-19 mg cmwas studied.The results show the high capability of MRXI to detect MNPs in a human head sized volume. Superficial sources with a concentration larger than 12 mg cmcould be reconstructed with a resulotion of about 1 cm.The reconstruction of the MNP distribution, mimicking a GBM tumor of 7 cmvolume with clinically relevant iron concentration, demonstrates thefeasibility of MRXI in humans.