Wang Shunmin, Shi Jiangang, Li Tiefeng, Zhang Xiaofeng, Sun Kaiqiang, Chen Yu
Department of Orthopedic Surgery, Spine Center, Changzheng Hospital, Naval Medical Center of PLA, Shanghai, China.
Department of Orthopedics, Naval Medical Center of PLA, 200052, Shanghai, P.R. China.
Neuroradiology. 2025 Sep 25. doi: 10.1007/s00234-025-03762-3.
To quantify region-specific T2 relaxation dynamics in lumbar disc degeneration and evaluate their correlations with Pfirrmann grades and herniation morphology, focusing on early microstructural detection.
This retrospective cohort study analyzed 130 lumbar discs (L1-S1) from 26 patients with single-segment disc herniation using 3.0-T MRI. T2 relaxation mapping was systematically performed with anatomical compartment segmentation defining four regions of interest: anterior annulus fibrosus, nucleus pulposus, posterior annulus fibrosus, and herniated tissue. Standardized circular ROIs (2.5-mm diameter) were applied to non-herniated regions, while herniations underwent area-matched elliptical contouring. Pfirrmann grading (I-V) was independently validated by two board-certified musculoskeletal radiologists. Statistical analyses employed nonparametric Kruskal-Wallis tests for inter-grade T2 comparisons and Spearman's rank correlation (ρ) to quantify degeneration associations.
Statistically significant differences in T2 values were observed across the three anatomical compartments (p<0.05). T2 relaxation times demonstrated an inverse correlation with Pfirrmann degeneration grades, exhibiting the strongest association in the nucleus pulposus (middle compartment; r=-0.542). This correlation intensified with advancing degeneration. Sagittal T2 comparisons revealed significant differences between Pfirrmann grade I/II and IV/V groups in all compartments, while the nucleus pulposus showed significant differences between grades I/II and III. Within identical degeneration grades, nucleus pulposus T2 values exceeded those of the anterior annulus fibrosus. Specifically, in Pfirrmann I/II discs, posterior annulus values surpassed anterior annulus values, whereas in grade IV/V discs, nucleus pulposus values exceeded posterior annulus values, with no significant anterior-posterior difference. Cross-sectionally, the nucleus pulposus exhibited the highest T2 values, while herniated tissue demonstrated the lowest.
Region-specific T2 mapping demonstrates potential for detecting early microstructural degeneration within lumbar intervertebral discs.
量化腰椎间盘退变中特定区域的T2弛豫动力学，并评估其与Pfirrmann分级及突出形态的相关性，重点关注早期微观结构检测。
这项回顾性队列研究使用3.0-T MRI分析了26名单节段椎间盘突出症患者的130个腰椎间盘（L1-S1）。通过解剖腔室分割系统地进行T2弛豫映射，定义四个感兴趣区域：前纤维环、髓核、后纤维环和突出组织。标准化圆形ROI（直径2.5毫米）应用于非突出区域，而突出部分采用面积匹配的椭圆形轮廓。Pfirrmann分级（I-V）由两名经委员会认证的肌肉骨骼放射科医生独立验证。统计分析采用非参数Kruskal-Wallis检验进行分级间T2比较，并采用Spearman等级相关性（ρ）来量化退变关联。
在三个解剖腔室中观察到T2值存在统计学显著差异（p<0.05）。T2弛豫时间与Pfirrmann退变分级呈负相关，在髓核（中间腔室；r=-0.542）中表现出最强的关联。这种相关性随着退变进展而增强。矢状面T2比较显示，Pfirrmann I/II组和IV/V组在所有腔室中均存在显著差异，而髓核在I/II级和III级之间存在显著差异。在相同的退变分级内，髓核T2值超过前纤维环。具体而言，在Pfirrmann I/II椎间盘内，后纤维环值超过前纤维环值，而在IV/V级椎间盘中，髓核值超过后纤维环值，前后无显著差异。横断面来看，髓核T2值最高，而突出组织T2值最低。
特定区域的T2映射显示出检测腰椎间盘早期微观结构退变的潜力。
