Inversion recovery magnetic resonance elastography (IR-MRE) is a new acquisition technique that performs MRE while selectively nulling the signal generated by one compartment with a specific T1. In phantom and in vivo experiments, free fluid, water or cerebrospinal fluid, was nulled. The shear wave speed (SWS) maps showed no overall change in average values. However, in cortical areas, IR-MRE revealed cortical SWS values 10% higher than in standard MRE, resulting in sharper tissue-CSF interfaces. Besides, ventricles are 39% narrower in IR-MRE than in MRE. In conclusion, IR-MRE allows a more precise quantification of cortical stiffness.