Henry H. Ong1, Joseph J. Sarver2, Jason E. Hsu2, Louis J. Soslowsky2, Felix W. Wehrli1
1Laboratory for Structural NMR Imaging, Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, PA, United States; 2McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA, United States
Tendons are comprised of parallel collagen fibers that connect muscles to bone. Collagen-associated water has anisotropic rotational motion, which gives rise to residual dipolar splitting in 1H NMR. Double-quantum filtered (DQF) NMR and MRI can be used to observe the splitting and study the biophysical and structural properties of tendon. Here, we modified a DQF 1D spectroscopic imaging sequence to obtain 1H DQF spectra along the axis of the flexor digitorum profundus (FDP) tendons from rat hind limbs and show spectral differences in the region that wraps under the calcaneus, which experiences compressive forces.