Image-guided Diagnosis and Theraoy (IGDT) - Integrating Multimodal Strategies For Clinical Research

Subproject: Multimodal Magnetorelaxometry Imaging of Magnetic Nanoparticles

Duration
2022 – 2026

Principal Investigator (subproject)
Univ.-Prof. Dr.-Ing. Daniel Baumgarten

Collaboration partner
Medical University of Innsbruck

Coordinator
Univ.-Prof. Dr. Elke Gizewski

Funding
FWF doc.funds IGDT – Image-Guided Diagnostics and Therapy (P8500-041-011)

Staff
Mishuk Mitra, MSc.

Motivation and Goal
Magnetic nanoparticles (MNP) are a foremost type of nanomaterial with an elemental magnetic iron oxide core coated with a biocompatable funtionalized shell. The superparamagnetic core enables them to respond to external magnetic fields and can be manipulated (sensing, heating, and moving) inside the body. MNPs generate nonuniform local magnetic field and function as a contrast agent in MR imaging. Secondly, in a nonuniform magnetic field MNPs experience a force and tend to move against the field gradient, and this magnetic mobility of MNPs can be exploited as agents for magnetic drug targeting (controllable carriers of drugs). The third catagory is associated with the capability of MNPs to convert electromagnetic energy into thermal energy employed e.g. to destroy cancer cells, referred to as magnetic hyperthermia. However, hyperthermia demands a high concentration of particles (in the order of several mg/mL volume) to deposit sufficient heat quickly to annihilate tissues while minimizing collateral thermal damage to neighboring healthy tissue. Precise quantitative knowledge of the spatial in vivo distribution and local environment of MNPs within an organism is essential before, during, and after therapy. This understanding is critical for several reasons: the thermal dose is directly proportional to iron concentration, which is vital for effective treatment; it supports therapy planning and supervision for targeted approaches; it facilitates the monitoring and prediction of treatment effects to enhance outcomes; and it helps evaluate efficacy and safety to reduce patient risks. MRI is a clinically established modality and MNPs have been employed as MRI contrast agents for its biocompatibility and magnetic characteristics. MRI provides anatomical information, whereas quantification of such high dose is challenging. On the other hand, Magnetorelaxometry imaging (MRXI) is a sensitive imaging technique that provides both quantitative and qualitative information of MNPs by detecting their magnetic response. But depending on the nature of the forward model, the process of inverse calculation often ill-posed due to the lack of tissue-specific spatial information and data acquisition takes a considerably long time. In these circumstances, we would like to establish a multimodal system combining MR and MRX imaging for the monitoring of hyperthermia treatment in order to facilitate the clinical translation.