Magic Sandwich to Stimulated Echo Relative change to identify sign and intensity of dipolar interaction in anisotropic tissue

Among the MR techniques playing on dipolar interaction (Hd), the magic sandwich echo sequence (MSE) is very seldom used in biological application. So far, the magic echo has been compared to the spin echo. However, MSE is closer to a stimulated echo thus a Magic Sandwich to Stimulated echo relative change (MaSteR) is of interest to study. The MaSteR evolution with spin-lock intensity increase was studied for thawed tendon for different orientations within B0 to modulate the dipolar interaction. We show that MaSteR is correlated to dipolar interaction, sample composition and its evolution with orientation is sensitive to Hd sign. Summary (250 characters): A marker of macromolecular dipolar interactions (Hd) is introduced as the Magic Sandwich to Stimulated Echo relative change (MaSteR). Different B1 spin lock intensities are used to modulate Hd. MaSteR is sensitive to Hd sign and fiber orientation.