Department of Radiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, 200072, Shanghai, China.
Clin Neuroradiol. 2018 Dec;28(4):529-537. doi: 10.1007/s00062-017-0621-9. Epub 2017 Aug 21.
Nerve root compression by lumbar disc herniation (LDH) induces a series of clinical symptoms, seriously affecting the patient's life and work. The purpose of this study is to investigate microstructural changes and fiber bundle abnormalities of the compressed L5 and S1 nerve roots in young patients with unilateral LDH by using diffusion tensor imaging (DTI).
Forty young patients with unilateral LDH and 17 healthy volunteers participated in the study, and 33 patients received follow-up DTI examination after one month of conservative treatment. Fractional anisotropy (FA), apparent diffusion coefficient (ADC) and trace weight (TraceW) values of the L5 and S1 nerve roots were measured on FA maps.
The mean FA, ADC and TraceW values of the affected nerve roots were 0.259 ± 0.047, 1.79 ± 0.252 and 0.076 ± 0.025, respectively. Compared to the contralateral side and volunteers, the affected nerve roots showed a decreased FA (P < 0.01), an increased ADC (P < 0.01) and TraceW (P < 0.05). The compression severity had a moderately negative correlation with FA (r = -0.646, P < 0.01) and positive correlation with ADC (r = 0.408, P < 0.01) but not with TraceW (r = 0.298, P = 0.06). For 33 patients with follow-up study after conservative treatment, FA (0.286 ± 0.06) and ADC (1.630 ± 0.046) in the affected nerve roots showed an increasing and a decreasing trend, respectively. Moreover, FA values (14 cases; 0.246 ± 0.015, P = 0.213) in the severe compression group had no significant changes between initial and follow-up data.
DTI is able to assess microstructural abnormalities of the compressed nerve roots and has potentially practical value for prognostic evaluation after treatment in patients with LDH.
腰椎间盘突出症（LDH）导致神经根受压，引发一系列临床症状，严重影响患者的生活和工作。本研究旨在通过弥散张量成像（DTI）研究青年单侧 LDH 患者受压的 L5 和 S1 神经根的微观结构变化和纤维束异常。
40 例单侧 LDH 青年患者和 17 例健康志愿者参与了研究，其中 33 例患者在接受 1 个月的保守治疗后接受了随访 DTI 检查。在 FA 图上测量 L5 和 S1 神经根的各向异性分数（FA）、表观扩散系数（ADC）和迹线重量（TraceW）值。
患侧神经根的平均 FA、ADC 和 TraceW 值分别为 0.259±0.047、1.79±0.252 和 0.076±0.025。与对侧和志愿者相比，患侧神经根的 FA 值降低（P<0.01），ADC 值升高（P<0.01），TraceW 值升高（P<0.05）。压迫严重程度与 FA 值呈中度负相关（r=-0.646，P<0.01），与 ADC 值呈正相关（r=0.408，P<0.01），与 TraceW 值无相关性（r=0.298，P=0.06）。对于 33 例接受保守治疗后随访的患者，患侧神经根的 FA（0.286±0.06）和 ADC（1.630±0.046）均呈升高和降低趋势。此外，严重压迫组的 FA 值（14 例；0.246±0.015，P=0.213）在初始和随访数据之间无显著变化。
DTI 能够评估受压神经根的微观结构异常，对于 LDH 患者治疗后的预后评估具有潜在的实用价值。
