Dipolar Anistropy Reveals Sub-Structures in Achilles Tendon at 11.7 Tesla

Nikolaus M. Szeverenyi¹, Paul A. DiCamillo¹, Graeme M. Bydder²

Residual dipolar effects influence T2 relaxation times and are responsible for the magic angle effects known in MR imaging. In this study we manipulated the orientation of a human Achilles specimen in an 11.7 T animal system producing high contrast images, which at certain orientations revealed fine sub-structures that could not otherwise be observed. A 17-fold change in signal intensity was obtained for the most fibrous structures. Coefficient of variation images were computed from co-registered datasets (DAFI approach) providing a new tissue parameter and a novel technique for visualizing fiber content.