Quantification of Intervertebral Disc Tears by High-Resolution 3D MRI at 7T

INTRODUCTION The intervertebral disc (IVD) undergoes more extensive structural and compositional changes with age and degeneration than any other musculoskeletal tissue. With age and degeneration, tears appear within discs due to limiting diffusion of nutrients into the disc, alteration of chemical composition, and injuries. Disc tears are associated with low back pain [1,2]. The current clinical understanding of tears is that tears radiating to the outer third of the annulus fibrosis (AF) may cause low back pain [1]. However, detection of tears is difficult and quantification of their characteristics is not possible. Radial tears are often visualized under discography, however their location and orientation is difficult to determine [3]. Additionally, discography is an invasive procedure and involves exposure to radiation. The literature is replete with cadaveric studies using histology or gross sections showing a high incidence of AF tears [4,5]. However, shapes and sizes of tears are intricate, and even multiple histological sections cannot reconstruct the complex 3D tear geometry. As a result, quantitative characteristics of the 3D human AF tear remain largely unknown. The objective of this study is to provide a non-invasive MR technique for 3D visualization, measurement, and the ability to precisely locate disc tear orientation within a disc.