Highly Crosslinked pAA-PEGDA Hydrogels for T1 modification in Quantitative, Anthropomorphic Phantoms

Motivation: Phantoms are tremendously useful for advancing quantitative MRI (qMRI). But anthropomorphic phantoms that truly mimic anatomy and the heterogeneity of relaxation parameters in tissue are still out of reach. Goal(s): Our work aims to develop reproducible methods for stable control of T1 modulation in UV curable hydrogels without paramagnetic ions that often diffuse without water-tight boundaries. Approach: We modulate T1 by modifying the polymeric network of our polyacrylamide-polyethylene glycol (pAA-PEGDA) hydrogels,enabling boundaryless T1 contrast between compartments. Results: Our solution is able to bypass issues of dopant diffusion to create stable, precisely bounded regions of hydrogel with distinct T1 values. Impact: A reliable, quantitative method for T1 modification in boundaryless hydrogel systems presents a significant opportunity for development in anthropomorphic phantoms. These phantoms have the potential to accelerate the development of quantitative MRI by making research more standardized, reliable, and accessible.