Quantitative MRI in early intervertebral disc degeneration: T1rho correlates better than T2 and ADC with biomechanics, histology and matrix content

PLoS One. 2018 Jan 30;13(1):e0191442. doi: 10.1371/journal.pone.0191442. eCollection 2018.

Abstract

Introduction: Low-back pain (LBP) has been correlated to the presence of intervertebral disc (IVD) degeneration on T2-weighted (T2w) MRI. It remains challenging, however, to accurately stage degenerative disc disease (DDD) based on T2w MRI and measurements of IVD height, particularly for early DDD. Several quantitative MRI techniques have been introduced to detect changes in matrix composition signifying early DDD. In this study, we correlated quantitative T2, T1rho and Apparent Diffusion Coefficient (ADC) values to disc mechanical behavior and gold standard early DDD markers in a graded degenerated lumbar IVD caprine model, to assess their potential for early DDD detection.

Methods: Lumbar caprine IVDs were injected with either 0.25 U/ml or 0.5 U/ml Chondroïtinase ABC (Cabc) to trigger early DDD-like degeneration. Injection with phosphate-buffered saline (PBS) served as control. IVDs were cultured in a bioreactor for 20 days under axial physiological loading. High-resolution 9.4 T MR images were obtained prior to intervention and after culture. Quantitative MR results were correlated to recovery behavior, histological degeneration grading, and the content of glycosaminoglycans (GAGs) and water.

Results: Cabc-injected IVDs showed aberrancies in biomechanics and loss of GAGs without changes in water-content. All MR sequences detected changes in matrix composition, with T1rho showing largest changes pre-to-post in the nucleus, and significantly more than T2 and ADC. Histologically, degeneration due to Cabc injection was mild. T1rho nucleus values correlated strongest with altered biomechanics, histological degeneration score, and loss of GAGs.

Conclusions: T2- and T1rho quantitative MR-mapping detected early DDD changes. T1rho nucleus values correlated better than T2 and ADC with biomechanical, histological, and GAG changes. Clinical implementation of quantitative MRI, T1rho particularly, could aid in distinguishing DDD more reliably at an earlier stage in the degenerative process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biomechanical Phenomena
  • Disease Progression
  • Female
  • Glycosaminoglycans / metabolism
  • Goats
  • Intervertebral Disc Degeneration / diagnostic imaging*
  • Intervertebral Disc Degeneration / metabolism
  • Intervertebral Disc Degeneration / pathology*
  • Intervertebral Disc Degeneration / physiopathology
  • Magnetic Resonance Imaging*
  • Mechanical Phenomena*
  • Signal-To-Noise Ratio
  • Time Factors
  • Water / metabolism

Substances

  • Glycosaminoglycans
  • Water

Grant support

This work is supported by the Dutch Government ZonMw Program “Alternatives for life animal testing”: grant number 11400090. The development of the LDCS is co-funded by the Dutch Ministry of Economic Affairs, Agriculture and Innovation led Government research program IDiDAS for the development of BioMedical Materials: BMM project number P2.01.