磁共振成像在腰椎间盘退变定量分析中的应用研究

Study of Application on Quantitative Analysis of Lumbar Intervertebral Disk Degeneration with Magnetic Resonance Imaging

目的探讨腰椎间盘的横向弛豫T2时间与患者年龄、椎间盘退变分级之间的相关性,分析T2横向弛豫时间对腰椎间盘退变的诊断价值。方法对22位患者110个椎间盘进行了矢状位T1加权成像(TIWI)和T2加权成像(T2WI)、轴位加权像(T2WI)及正中矢状位T2 map成像。两位医师对图像进行检测,根据Pfirrmann标准将L1-S1椎问盘分级,测量每个腰椎体髓核及纤维环前后缘平均T2弛豫时间,并对T2弛豫时间进行比较,采用秩和检验和Pearson相关分析对髓核与年龄、退变分级的相关性进行分析。结果对110个腰椎间盘的T2横向弛豫时间进行了计算,48个椎间盘被分类为PfirrmannⅡ级;37例为Ⅲ级;17例为Ⅳ级;8例为Ⅴ级。腰椎间盘髓核T2值随分级增高而降低(P<0.01);纤维环T2值与分级无明显相关性(P>0.05);腰椎间盘髓核T2值与受试者年龄呈显著负相关(P<0.01),纤维环T2值与受试者年龄无明显相关性(P>0.05)。结论腰椎间盘的横向弛豫时间与退变等级和患者年龄有关联性,MRI横向弛豫时间测量可以作为一种无创、早期定量评价年龄与腰椎间盘退变程度的方法。

Objective To correlate T2 relaxation times in lumbar disks with patient age and stage of degeneration, and To evaluate the clinical value of T2 map for detecting of lumbar intervertebral disk degeneration.Methods Sagittal T1-and T2-weighted images and axial images and Sagittal T2 map images were acquired in 22 patients referred for MR imaging for back pain or radiculopathy. Two readers inspected these images and assigned a Pfirrmann grade to each disk participants. Disks from LI to S1 were classified based on the Pfirrmann grading systerm.Mean T2 relaxation time of all nucleus pulposusf（NP）, anterior and posterior annulus fibrosus（AF） were measured and their variances in different grades were analyzed by one-way Kruskal Wallis and person correlation analysis.Results T2 relaxation times were calculated for 110 lumbar disks in 22 patients, 48 disks were classified as Pfirrmann grade II; 37 ones as grade III; 17 ones as grade IV; and 8 ones as grade V. T2 relaxation time of NP was decreased with increase of the lumbar intervertebral disk degeneration grade（P〈0.01）; T2 relaxation time of mean AF was no of significant changes with the lumbar intervertebral disk degeneration grade（P〉0.05）. T2 relaxation time of NP was decreased with increase of the age（P〈0.01）; T2 relaxation time of mean AF was no of significant changes with the age（P〉0.05）. Conclusions T2 relaxation times in lumbar disks correlate with stage of degeneration and patient age.T2 measurement of NP is a non-invasive and quantitative tool for detecting the lumbar intervertebral disk degeneration early stage based on T2 map.