Sodium MRI of the Lumbar Intervertebral Discs of the Human Spine: An Ex Vivo Study

• Published in: Journal of magnetic resonance imaging
• Main Authors: Kamp, Benedikt, Radke, Karl Ludger, Knet, Marek, Strunk, Rosanna, Gallinnis, Patrik J, Nagel, Armin M, Filler, Timm J, Antoch, Gerald, Abrar, Daniel B, Frenken, Miriam, Wittsack, Hans-Jörg, Müller-Lutz, Anja
• Format: Journal Article
• Language: English
• Published: United States 04.07.2024
• Subjects: 23Na MRI; sodium MRI; intervertebral disc; 23Na relaxation times; ex vivo; IVD
• ISSN: 1053-1807; 1522-2586; 1522-2586
• DOI: 10.1002/jmri.29521

Lower back pain affects 75%-85% of people at some point in their lives. The detection of biochemical changes with sodium ( Na) MRI has potential to enable an earlier and more accurate diagnosis. To measure Na relaxation times and apparent tissue sodium concentration (aTSC) in ex-vivo intervertebral discs (IVDs), and to investigate the relationship between aTSC and histological Thompson grade. Ex-vivo. Thirty IVDs from the lumbar spines of 11 human body donors (4 female, 7 male, mean age 86 ± 8 years). 3 T; density-adapted 3D radial sequence (DA-3D-RAD). IVD Na longitudinal (T ), short and long transverse (T * and T *) relaxation times and the proportion of the short transverse relaxation (p ) were calculated for one IVD per spine sample (11 IVDs). Furthermore, aTSCs were calculated for all IVDs. The degradation of the IVDs was assessed via histological Thompson grading. A Kendall Tau correlation (τ) test was performed between the aTSCs and the Thompson grades. The significance level was set to P < 0.05. Mean Na relaxation parameters of a subset of 11 IVDs were T  = 9.8 ± 1.3 msec, T * = 0.7 ± 0.1 msec, T * = 7.3 ± 1.1 msec, and p  = 32.7 ± 4.0%. A total of 30 IVDs were examined, of which 3 had Thompson grade 1, 4 had grade 2, 5 had grade 3, 5 had grade 4, and 13 had grade 5. The aTSC decreased with increasing degradation, being 274.6 ± 18.9 mM for Thompson grade 1 and 190.5 ± 29.5 mM for Thompson grade 5. The correlation between whole IVD aTSC and Thompson grade was significant and strongly negative (τ = -0.56). This study showed a significant correlation between aTSC and degenerative IVD changes. Consequently, aTSC has potential to be useful as an indicator of degenerative spinal changes. 2 TECHNICAL EFFICACY: Stage 1.