Co-electrohydrodynamic Forming of Biomimetic Polymer Materials for Diffusion Magnetic Resonance Imaging

Abstract

Magnetic resonance imaging (MRI) is routinely used as a medical imaging modality in the disease detection, monitoring, and therapy response assessment in neurology and cancer. An attractive feature of MRI is its ability to provide non-invasive quantitative measurements relating to the tissue microenvironment. In MRI, a technique known as diffusion MRI can provide non-invasive quantitative information that is reflective of the microstructure of tissues, ranging from measurements of axonal packing in the brain, through measurements of myocardial fiber orientation in the heart to measurements of tumor cell size. These measurements are powerful, but they are not commonly used clinically, in part due to a lack of validation. Synthetic tissues, with known microstructural properties, provide one approach to providing such validation. This chapter presents how co-electrohydrodynamic (co-EHD) forming of polymer materials can be used to create synthetic tissues (or phantoms) for diffusion MRI by mimicking the cellular structure of tissues in the brain, heart, and tumor. Two types of co-EHD polymeric structures, i.e. hollow microfibres and microspheres, will be discussed with the focus on the shell and core materials and the relevant processes used. Three types of tissue-mimicking phantoms and their performance in pre-clinical or clinical MRI measurements will be highlighted.