High-Resolution Quantitative T1-Based Cortical Thickness Estimates at 7 Tesla

Christine Lucas Tardif¹, Pierre-Louis Bazin¹, Andreas Schfer¹, Robert Turner¹

Cortical thickness estimates typically derive from T1-weighted images at 1 mm isotropic resolution acquired at 1.5 or 3 Tesla. A recent study claims that cortical thickness is over-estimated using standard techniques at this spatial resolution, and that using higher resolution T1-weighted images improves measurement accuracy. We developed new tools to extract cortical boundaries and measure cortical thickness from high-resolution quantitative T1 maps. We measured cortical thickness for 12 subjects scanned using the MP2RAGE sequence at 0.9, 0.7 and 0.5 mm isotropic resolution. The results are stable across resolutions, and become more precise at 0.5 mm.