MRI T2* mapping correlates with biochemistry and histology in intervertebral disc degeneration in a large animal model

作者：Detiger Suzanne E L; Holewijn Roderick M; Hoogendoorn Roel J W; van Royen Barend J; Helder Marco N; Berger Ferco H; Kuijer Joost P A; Smit Theo H^*

来源：European Spine Journal, 2015, 24(9): 1935-1943.

DOI：10.1007/s00586-014-3498-1

• Intervertebral disc degeneration
• Animal model
• Magnetic resonance imaging
• Glycosaminoglycan
• T2*(T2 star) mapping

To evaluate intervertebral disc (IVD) degeneration and treatments, an objective diagnostic tool is needed. Recently, T2* relaxation time mapping was proposed as a technique to assess early IVD degeneration, yet the correlation with biochemical content and histological features has not been investigated previously. Our objective was to validate T2* mapping for disc degeneration by correlating this technique with accepted parameters of IVD degeneration.
Mildly and severely degenerated lumbar discs were obtained from an in vivo large animal study; two healthy goat spines were acquired as control. In total, 48 IVDs were analysed using T2-weighted MRI, T2* relaxation time mapping, biochemical assays, macroscopic and histological scoring. Correlations between variables were expressed with Spearman's rho (rho) coefficients.
A complete range of degenerative grades were obtained (mean histological grade 2.2, range 0-6). A linear positive correlation was observed between T2* relaxation time and glycosaminoglycan content (rho = 0.64, p < 0.001). T2* relaxation time decreased linearly with increasing degeneration as assessed with Pfirrmann scoring system (rho = -0.67, p < 0.001), macroscopic (rho = -0.33, p < 0.05) and histological (rho = -0.45, p < 0.05) grading.
T2* mapping is an MRI technique for IVD evaluation which allows for measurements on a continuous scale thus minimising observer bias compared to grading systems. Although limited by a small sample size, this study showed a relatively good and linear correlation between T2* relaxation time and accepted parameters of disc degeneration. This suggests that T2* mapping is a promising tool to assess disc degeneration in clinical practice.

• 出版日期2015-9