运用化学交换饱和转移技术的磁共振成像方法对腰椎间盘早期退行性变的定量评估

目的 探讨黏多糖化学交换饱和转移(glycosaminoglycan chemical exchange saturation transfer,gagCEST)磁共振成像在腰椎间盘退变早期、定量诊断中的价值.方法 纳入2016年5月至2017年5月陆军军医大学第一附属医院37例年龄18 ～ 74岁有或无腰椎间盘退变的受试者,观察其L1/2～L5/S1五个椎间盘,共185个椎间盘.将185个椎间盘的T2WI按Pfirrmann分级标准,半定量地分为5级,检测其髓核与纤维环的T2*与gagCEST两个定量磁共振参数并做统计分析.结果 腰椎间盘髓核与纤维环的T2*与gagCEST在不同退变程度之间均具有一定的组间差异性,尤其是gagCEST在正常组与早期退变组之间差异具有统计学意义(P＜0.05),并且gagCEST与Pfirrmann分级显示出比T2*有更好的等级相关性(髓核:r=-0.951,P＜0.001;纤维环:r=-0.938,P＜0.001).结论 化学交换饱和转移技术的磁共振成像方法可用于对腰椎间盘退变的早期、定量诊断,也可评估椎间盘退变的程度.

Quantificational evaluation for early degeneration of lumbar intervertebral disc by magnetic resonance imaging based on chemical exchange saturation transfer

Objective To investigate the values ot magnetic resonance imaging (MRI) with glycosaminoglycan chemical exchange saturation transfer (gagCEST) for the early diagnosis and quantitative evaluation of lumbar disc degeneration.Methods Thirty-seven subjects (aged from 18 ～ 74 years) with or without lumbar disc degeneration admitted in the First Affiliated Hospital of Army Medical University from May 2016 to May 2017 were enrolled in this study.Their 5 discs (from L1/2 to L5/S1), totally 185 discs were observed by using MRI with gagCEST.According to Pfirrmann classification of lumbar intervertebral disc degeneration, these discs were semi-quantitatively divided into 5 level groups.The T2 * relaxation time and gagCEST value of nucleus pulposus (NP) and annulus fibrosus (AF) in the discs were measured, and then analyzed statistically.Results Certain differences were observed in T2 * relaxation time and gagCEST value of NP and AF among the 5 level groups.There were significant differences in the above values between the normal group and mild degeneration group.In addition, the gagCEST of the discs showed better rank correlation with the degeneration levels than T2 * MRI parameter (NP:r =-0.951, P ＜0.001;AF:r =-0.938, P ＜ 0.001).Conclusion MRI based on gagCEST can be used for early and quantitative diagnosis and severity assessment of lumbar disc degeneration.