MR imaging and T2 measurements in peripheral nerve repair with activation of Toll-like receptor 4 of neurotmesis
MR imaging and T2 measurements in peripheral nerve repair with activation of Toll-like receptor 4 of neurotmesis
复制标题
DOI：
10.1007/s00330-014-3134-9
复制
发表时间：
2014-02
影响因子：
5.9
通讯作者：
Xiang Zhang;Fang Zhang;Liejing Lu;Haojiang Li;X. Wen;Jun Shen
中科院分区：
文献类型：
--
作者：
Xiang Zhang;Fang Zhang;Liejing Lu;Haojiang Li;X. Wen;Jun Shen
目的探讨磁共振成像在神经切断联合手术修复和Toll样受体4（TLR4）激活中的作用。方法48只大鼠在坐骨神经横断手术修复后立即经神经束下微量注射TLR4激动剂脂多糖（LPS，n= 24）或磷酸盐缓冲盐水（PBS，n= 24）。在术后 3、7、14 和 21 天获得连续脂肪抑制 T2 加权成像和定量 T2 测量，并定期进行组织学评估。测量并比较远端残端的T2弛豫时间和组织学定量。结果LPS或PBS处理的横断神经远端残端均表现出持续增大和高信号。远端树桩的 T2 值在用 LPS 处理的神经中显示出快速上升到峰值水平，然后快速下降的模式，而在用 PBS 处理的神经中表现出缓慢上升到峰值然后缓慢下降的模式。用LPS处理的神经表现出更显着的巨噬细胞募集、更快的髓鞘碎片清除和更明显的神经再生。结论用TLR4激活处理的神经具有T2值随时间变化的特征模式。纵向 T2 测量可用于检测神经断裂手术修复中与 TLR4 激活相关的增强修复效果。要点• TLR4 激活对神经断裂具有手术修复之外的额外有益效果。• TLR4 激活具有 T2 值的特征时间过程。• T2 测量可帮助检测 TLR4 激活的有益效果。
ObjectiveTo investigate the role of MR imaging in neurotmesis combined with surgical repair and Toll-like receptor 4 (TLR4) activation.MethodsForty-eight rats received subepineurial microinjection of the TLR4 agonist lipopolysaccharide (LPS,n= 24) or phosphate buffered saline (PBS,n= 24) immediately after surgical repair of the transected sciatic nerve. Sequential fat-suppressed T2-weighted imaging and quantitative T2 measurements were obtained at 3, 7, 14 and 21 days after surgery, with histologic assessments performed at regular intervals. T2 relaxation times and histological quantification of the distal stumps were measured and compared.ResultsThe distal stumps of transected nerves treated with LPS or PBS both showed persistent enlargement and hyperintense signal. T2 values of the distal stumps showed a rapid rise to peak level followed by a rapid decline pattern in nerves treated with LPS, while exhibiting a slow rise to peak value followed by a slow decline in nerves treated with PBS. Nerves treated with LPS exhibited more prominent macrophage recruitment, faster myelin debris clearance and more pronounced nerve regeneration.ConclusionNerves treated with TLR4 activation had a characteristic pattern of T2 value change over time. Longitudinal T2 measurements can be used to detect the enhanced repair effect associated with TLR4 activation in the surgical repair of neurotmesis.Key points• TLR4 activation had additional beneficial effects on neurotmesis beyond surgical repair.• TLR4 activation had a characteristic time course of T2 values.• T2 measurements can help detect beneficial effects with TLR4 activation.