无症状志愿者腰椎间盘磁共振定量测量研究

摘要

Objective To measure T2 relaxation time of the lumbar intervertebral disk in asymptomatic volunteers as a reference for detecting early stage of disk degeneration.Methods 37 asymptomatic volunteers underwent MR imaging with sagittal fast spin echo T2WI and T2 mapping at 1.5 Tesla MRI.185 disks from L1 to S1 were classified based on the Pfirrmann's grading system.The correlations between grades and ages were analyzed by Pearson's correlation test.Moreover, mean T2 relaxation time of all nucleus pulposus（NP） ,anterior and posterior annulus fibrosus （AF） were measured and their variances in different grades were analyzed by one-way ANOVA test.Results In total of 185 disks were measured and showed:① Linear regression analysis between grades and ages revealed significant positive correlation（r= 0.735,P＜0.01）; ②T2 relaxation time of NP was decreased with increase of the lumbar intervertebral disk degeneration（ IVDD） grade.The significant difference about mean T2 relaxation time of NP was found between any of different grades（P＜0.05 ） ;③T2 relaxation time of anterior and posterior AF was no of significant changes with the IVDD grades, and there was not significant difference about mean T2 relaxation time of AF between any of different grades （ P＞0.05）.Conclusion The lumbar intervertebral disks in asymptomatic volunteers exist age-related degeneration.The measurement of T2 relaxation time as the non- invasive and quantitative tool for detecting the age- related IVDD in early stage has a potential for clinical application.%目的 通过测量无症状志愿者的椎间盘MRI横向弛豫时间,为早期判断椎间盘退变提供参考.方法 37名无症状志愿者行腰椎1.5T MRI矢状位T2WI及正中矢状位T2 mapping成像,根据Pfirrmann标准将185个L1～S1椎间盘分级,并测量髓核及纤维环前后缘T2弛豫时间.采用单因素方差分析分别比较各级髓核和纤维环前后缘T2弛豫时间有无显著性差异,并进行年龄与退变分级的Pearson's相关性分析.结果 共计测量185个椎间盘,统计结果示:①无症状志愿者年龄与椎间盘分级呈显著正相关,r＝0.735,P＜0.01;②腰椎间盘各分级髓核平均T2弛豫时间随分级的增高而减小,各分级平均T2弛豫时间统计学均有显著性差异,P值均＜0.05;③腰椎间盘纤维环各分级前后缘平均T2弛豫时间值随分级的增高未见明显变化,各级之间统计学均未见明显显著性差异,P值均＞0.05.结论 无症状志愿者腰椎间盘存在年龄相关性退变,MRI横向弛豫时间测量可以作为一种潜在的无创、早期定量评价年龄与腰椎间盘退变程度的手段.