Courtesy of Dr Lucy Hiscox and Prof Neil Roberts, this image shows Magnetic Resonance Elastography (MRE) of the hippocampus, a brain structure within the medial temporal lobe involved in the formation of new memories. MRE is an MRI-based technique sensitive to the mechanical properties of tissue, such as viscoelasticity. In a study of healthy older adults, a significant correlation was found between better recall performance on a verbal memory task and lower relative viscous-to-elastic behavior (i.e. damping ratio, ξ) of the left hippocampus measured with MRE. Higher ξ values indicate a more viscous fluid, while low ξ values indicate a more elastic solid. Example left hippocampus damping ratio images are depicted above for a participant with a high memory recall score (and lower ξ) at left and for a participant with a low memory recall score (higher ξ) at right.
The image is taken from a recent study published in Brain Imaging and Behavior:
Hiscox LV, Johnson CL, McGarry MDJ, Schwarb H, van Beek EJR, Roberts N, Starr JM. Hippocampal viscoelasticity and episodic memory performance in healthy older adults examined with magnetic resonance elastography. Brain Imaging Behav 2018; Epub ahead of print.
More information on the MRE technique can be found accompanying a previous Image of the Month, here.