The Effects of Cross-Sectional Asymmetry & Anisotropy of the Pore Space on Double-PFG MR Signal

Evren Ozarslan^1,2, Peter Joel Basser¹

Previous theoretical studies performed to relate the pore morphology to the double pulsed field gradient (double-PFG) signal have assumed that the compartments are symmetric about their center of gravity. For example, axons have been envisioned to be cylinders with perfectly circular cross sections. To understand the effects of any asymmetry, we modeled an ensemble of infinitely long tubes with wedge-shaped cross sections. The findings indicate that the signal behavior resembles that for symmetric pore shapes, and for reasonable levels of asymmetry, employing a model with an isotropic cross section would lead to only a slight overestimation of the compartment size.