Evaluating High-Resolution High-b-value OGSE Time-dependent Diffusion in Human Brain at Ultra-high-gradient 3.0T

Oscillating gradient spin echo (OGSE) time-dependent diffusion MRI has been shown to improve assessment of intra-cranial disease progression including glioma and multiple sclerosis. In human brain studies, however, high-resolution and high-b-value OGSE diffusion measurements suffer from low signal-to-noise ratio and Rician noise bias. In our preliminary studies with ultra-high-performance gradient 3.0T system, apparent diffusivity coefficient (ADC) of white matter at OGSE 35 Hz showed lower values when ADC was estimated from high b-values ≥1000 s/mm2 with 1.5-mm isotropic resolution, due to Rician noise bias. The effect of Rician noise bias on OGSE ADC measurement was reduced by using real-valued signals.