In vivo

In Vivo MRI Quantification of Human Disc Compression and Flexion/Extension

Disc function is mechanical, and measures of disc mechanical function are important to address spine function, degenerative disc disease, and low back pain. In vivo measures of disc mechanical function are needed, however the current standard in disc imaging is to acquire a single static image and classify the disc’s appearance using qualitative integer scales for degree of degeneration. Current grading standards are acknowledged as insufficient to identify symptomatic discs for treatment. In addition, static T2 weighted MRI cannot provide mechanical function information – mechanics must be measured as the change following a load or deformation perturbation. Because the disc experiences significant compression and height loss throughout the day, and because flexion-extension postures are often associated with low back pain, these physiological mechanical perturbations have potential to be used to quantify disc mechanics in vivo. The objective of this study was to use MRI-based methods to quantify in vivo disc function by measuring changes in disc geometry and T2 relaxation time with diurnal changes and with controllable posture. Quantification of in vivo disc mechanics by using diurnal loading or prescribed posture changes has potential to improve our ability to identify, evaluate, and treat degenerative disc disease. Symptomatic discs may have aberrant mechanics; if so, in vivo measurements of mechanical function may, with continued development, facilitate diagnosis of pathological discs.
Listed In: Biomechanical Engineering