Alexander C. Wright1, Steve Pickup2, Debra Horng1, Grace D. O'Connell3, Dawn M. Elliott3
1Laboratory for Structural NMR Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA; 2Small Animal Imaging Facility, Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA; 3McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA, USA
Within the annulus fibrosus (AF) of the intervertebral disc, collagen fibers play an important role in the distribution of mechanical forces. However, details of their three-dimensional structure have been difficult to measure. Using diffusion tensor imaging (DTI) at high isotropic resolution, we here report DTI measurements on a section of human AF tissue at 90-micron isotropic resolution. Resulting orientations of the principle eigenvector of the diffusion tensors show the expected variation in adjacent lamellae of about +/- 60. Furthermore, at this voxel size the collagen fibers are directly visible in the diffusion-weighted images.
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