Traditional clinical imaging has emphasized orthogonal T1- and T2-weighted imaging for morphologic assessment of the discovertebral complex. These sequences also provide an evaluation of the signal intensity changes associated with degenerative disk disease. Fast SE T2-weighted images have replaced conventional T2-weighted images because of their shorter acquisition times, but they provide no increased diagnostic advantage. Short inversion time inversion-recovery or fat-suppressed T2-weighted images have been added by many groups, ours included, because it is believed they are more sensitive to marrow and soft-tissue changes.
While these standard sequences remain the mainstay of diagnostic imaging of the spine, new techniques continue to be evaluated in hopes of providing stronger correlation between imaging findings and patient symptoms. The utility of many of these techniques for the routine evaluation of degenerative disk disease remains unknown, and the number of subjects in which they have been evaluated remains small. Nevertheless, these approaches may be important for redefining the direction of spinal imaging away from strictly anatomic one to one that combines more physiologic and functional information (76). Techniques that have been evaluated to greater or lesser degrees of success include assessment of spinal motion (dynamic imaging, kinetic assessment, or axial loading), diffusion imaging (water or contrast agents), MR neurography, spectroscopy, functional MR of the spinal cord, and ultrashort echo-time imaging. Of the variety of techniques available, only MR neurography and dynamic imaging have expanded beyond the experimental phase and have demonstrated specific clinical utility (albeit in niche or select populations).
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