Nakahashi Yuta, Saida Tsukasa, Yoshida Miki, Shindo Masashi, Yamada Koji, Ishimori Takao, Terakado Masataka, Amano Taishi, Ishiguro Toshitaka, Kwon Jihun, Nakajima Takahito
Department of Radiology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, Japan.
Department of Diagnostic and Interventional Radiology, University of Tsukuba Hospital, 2-1-1 Amakubo, Tsukuba, Ibaraki, Japan.
Skeletal Radiol. 2025 Jun 16. doi: 10.1007/s00256-025-04968-5.
This study aimed to evaluate the clinical applicability of Na-MRI for the quantitative assessment of lumbar intervertebral disc degeneration (IDD) by comparing Na signal intensities with T2-weighted imaging (T2WI), Pfirrmann classification, and clinical findings.
A phantom experiment using NaCl solutions was conducted to validate the relationship between Na signal intensity and sodium concentration. Lumbar Na-MRI and T2WI were performed on 40 patients. Apparent tissue sodium concentration (aTSC) was calculated using cerebrospinal fluid (CSF) as a reference. Correlations between aTSC and T2 ratio, disc thickness, and Pfirrmann grade were assessed using linear mixed-effects models. Associations between mean aTSC across three discs and age and body mass index (BMI) were evaluated using Pearson's correlation, while differences by self-reported low back pain severity were evaluated using Welch's ANOVA. Differences across Pfirrmann grades were tested using Wald tests with FDR-corrected pairwise models.
The phantom experiment demonstrated a strong linear relationship between sodium concentration and Na signal intensity (R = 0.996). In the clinical study, aTSC was significantly associated with T2 ratio (β = 154.5, P < 0.001) and disc thickness (β = 3.38, P = 0.020), inversely correlated with age (r = -0.630, P < 0.001), and not significantly correlated with BMI. aTSC significantly differed across Pfirrmann grades (P < 0.001). Patients with severe back pain had significantly lower aTSC than those without pain (P = 0.005).
Na-MRI enables quantitative, clinically feasible evaluation of lumbar IDD and may serve as a non-invasive biomarker for disc degeneration severity.
本研究旨在通过比较钠（Na）信号强度与T2加权成像（T2WI）、Pfirrmann分级及临床结果，评估钠磁共振成像（Na-MRI）在定量评估腰椎间盘退变（IDD）方面的临床适用性。
进行了一项使用氯化钠溶液的模型实验，以验证Na信号强度与钠浓度之间的关系。对40例患者进行了腰椎Na-MRI和T2WI检查。以脑脊液（CSF）为参考计算表观组织钠浓度（aTSC）。使用线性混合效应模型评估aTSC与T2比值、椎间盘厚度和Pfirrmann分级之间的相关性。使用Pearson相关性评估三个椎间盘的平均aTSC与年龄和体重指数（BMI）之间的关联，而使用Welch方差分析评估自我报告的腰痛严重程度的差异。使用经FDR校正的成对模型的Wald检验来检验Pfirrmann分级之间的差异。
模型实验表明钠浓度与Na信号强度之间存在强线性关系（R = 0.996）。在临床研究中，aTSC与T2比值（β = 154.5，P < 0.001）和椎间盘厚度（β = 3.38，P = 0.020）显著相关，与年龄呈负相关（r = -0.630，P < 0.001），与BMI无显著相关性。aTSC在Pfirrmann分级之间存在显著差异（P < 0.001）。严重背痛患者的aTSC显著低于无疼痛患者（P = 0.005）。
Na-MRI能够对腰椎IDD进行定量、临床可行的评估，并可作为椎间盘退变严重程度的非侵入性生物标志物。
