Kobayashi S, Uchida K, Takeno K, Baba H, Suzuki Y, Hayakawa K, Yoshizawa H
Department of Orthopaedics and Rehabilitation Medicine, Fukui University School of Medicine, Matsuoka, Fukui, Japan.
AJNR Am J Neuroradiol. 2006 Feb;27(2):346-53.
It has been reported that disturbance of blood flow arising from circumferential compression of the cauda equina by surrounding tissue plays a major role in the appearance of neurogenic intermittent claudication (NIC) associated with lumbar spinal canal stenosis (LSCS). We created a model of LSCS to clarify the mechanism of enhancement within the cauda equina on gadolinium-enhanced MR images from patients with LSCS.
In 20 dogs, a lumbar laminectomy was performed by applying circumferential constriction to the cauda equina by using a silicon tube, to produce 30% stenosis of the circumferential diameter of the dural tube. After 1 and 3 weeks, gadolinium and Evans blue albumin were injected intravenously at the same time. The sections were used to investigate the status of the blood-nerve barrier function under a fluorescence microscope and we compared gadolinium-enhanced MR images with Evans blue albumin distribution in the nerve. The other sections were used for light and transmission electron microscopic study.
In this model, histologic examination showed congestion and dilation in many of the intraradicular veins, as well as inflammatory cell infiltration. The intraradicular edema caused by venous congestion and Wallerian degeneration can also occur at sites that are not subject to mechanical compression. Enhanced MR imaging showed enhancement of the cauda equina at the stenosed region, demonstrating the presence of edema.
Gadolinium-enhanced MR imaging may be a useful tool for the diagnosis of microcirculatory disorders of the cauda equina associated with LSCS.
据报道，马尾神经受周围组织环形压迫导致的血流紊乱在与腰椎管狭窄症（LSCS）相关的神经源性间歇性跛行（NIC）的出现中起主要作用。我们建立了LSCS模型，以阐明LSCS患者钆增强磁共振图像上马尾神经内强化的机制。
对20只犬行腰椎椎板切除术，使用硅胶管对马尾神经进行环形缩窄，使硬脊膜管周径狭窄30%。在1周和3周后，同时静脉注射钆和伊文思蓝白蛋白。切片用于在荧光显微镜下研究血-神经屏障功能状态，并将钆增强磁共振图像与伊文思蓝白蛋白在神经中的分布进行比较。其他切片用于光镜和透射电镜研究。
在该模型中，组织学检查显示许多神经根内静脉充血、扩张，以及炎性细胞浸润。静脉充血和华勒变性引起的神经根内水肿也可发生在未受机械压迫的部位。增强磁共振成像显示狭窄区域的马尾神经强化，表明存在水肿。
钆增强磁共振成像可能是诊断与LSCS相关的马尾神经微循环障碍的有用工具。
