3.0T MR IDEAL和T_(2)mapping成像在腰椎间盘早期退变中的应用

The Application of 3.0T MR IDEAL and T_(2) Mapping Imaging in Early Lumbar Intervertebral Disc Degeneration

目的探讨3.0T磁共振IDEA和T2mapping成像在定量检测腰椎间盘早期退变中的应用价值。方法对35名(男18例,女17例,年龄21~30岁)健康志愿者行常规腰椎MRI及矢状位T2WI IDEAL成像、矢状位T2mapping成像,测量髓核(NP)、前纤维环(AAF)、后纤维环(PAF)的T2值及水信号分数(WSF)。分析腰椎间盘T2值、WSF值与Pfirrmann分级、性别及椎间盘层面的关系。结果AAF、NP、PAF的T2值与Pfirrmann分级间呈弱负相关(r值分别为-0.172、-0.48、-0.209,P均<0.05);WSF与NP、PAF间呈弱负相关(r值分别为-0.182、-0.189,P均<0.05);PfirrmannⅠ~Ⅱ级间PAF的WSF值,AAF及NP的T2值存在明显统计学差异;男性Ⅱ级NP的T2值、Ⅲ级NP的WSF值小于女性且有统计学差异;Ⅰ级PAF的T2值、WSF值随椎间盘层面的降低而减小且差异有统计学意义;Ⅱ级椎间盘AAF、NP的T2值不同椎间盘层面有统计学差异。结论T2值、WSF值与腰椎间盘退变程度有相关性,可量化评估不同性别及椎间盘层面,NP区明显。T2mapping技术联合IDEAL技术可作为评估腰椎间盘早期退变的定量依据。

Objective To evaluate the clinical value in early intervertebral disc degeneration quantified by IDEAL and T2 mapping imaging at 3.0T.Methods A total number of 35 healthy volunteers(18 males,17 females,range 21-30 years)underwent examination using a 3.0T MRI scanner.Both conventional imaging and sagittal T2 IDEAL imaging,sagittal T2 mapping were performed at every examination of the lumbar disc.The original scan data was transferred to AW 4.5 workstation for analyses.The sagittal T2 maps were reformatted for each disk.The mean of T2 and water signal fraction(WSF)values were calculated for anterior annulus fibrosus(AAF),nucleus pulposus(NP)and posterior annulus fibrosus(PAF)by using post-processing software.The degenerative grade of each lumbar disc was assessed from T2-WI images according to Pfirrmann degenerative grade.The correlativity between Pfirrmann grade and T2,as well as WSF values,were analyzed.Bivariate correlation analysis was performed to compare T2 values to the degenerative grade,gender and disc space level.Results T2 values of AAF,NP and PAF were significantly negatively correlated with Pfirrmann grade(r=-0.172,-0.48,-0.209,P<0.05)and WSF values of NP and PAF(r-0.182,-0.189,P<0.05).There was a significant difference in T2 values of AAF and NP,in WSF values of PAF between Pfirrmann gradeⅠ-Ⅱ.The significant diffrernces of T2 value of NP at gradeⅡ,WSF calues of NPat gradeⅢwere found among the gender groups;However,the T2 and WSF values of PAF decreased while the disc space level increased at gradeⅠ.T2 values of AAF and NP at gradeⅡwere statistically different at different intervertebral disc levels.Conclusion T2 and WSF values of Lumbar intervertebral discs demonstrated significant correlations with degenerative grade and related changes with gender and disk space levels,especiallyin NP.The IDEAL and T2 mapping imaging could be combined to be used as a quantitative basis for diagnosing early intervertebral disc degeneration.