T1 Estimation for Aqueous Iron Oxide Nanoparticle Suspensions Using a Variable Flip Angle SWIFT Sequence

Luning Wang¹, Curtis Andrew Corum², Djaudat Idiyatullin², Michael Garwood², Qun Zhao¹

Quantitative estimation of T1 is a challenging but important task inherent to many applications involving intrinsic or exogenous contrast agents in magnetic resonance imaging (MRI). Super-paramagnetic iron oxide (SPIO) nanoparticles have been used as T2 or T2* contrast agents, and as such, produce negative (reduced signal) contrast. Alternately, increasing numbers of recent studies have reported ways to generate T1-weighted positive contrast using the SPIO contrast agents. In the present work, the T1 values of water containing SPIO contrast agents were measured by sweep imaging with Fourier transformation (SWIFT) using variable flip angles (VFA-SWIFT).