3．0T磁共振T1ρ成像技术评估无症状飞行人员早期椎间盘退变的初步研究

Preliminary study of T1ρ imaging technique in assessment of early intervertebral disc degeneration in asymptomatic pilots on 3 .0T magnetic resonance

目的：利用3．0T磁共振T1ρ成像技术评估飞行人员早期椎间盘退变，并与对照组进行比较。方法行腰椎间盘磁共振扫描人员69名，其中飞行人员组：34名无腰痛症状的男性飞行人员；对照组：35名无腰痛症状的志愿者。椎间盘磁共振检查需同时采集常规矢状位T 2加权图像及T1ρ图像，图像数据全部上传至工作站，利用FUNCTOOL软件测定髓核中心 T1ρ值并生成伪彩图。依据常规矢状位T2加权图像对椎间盘进行Pfirrmann分级。分析飞行人员组与对照组的椎间盘髓核T1ρ值与Pfirrmann分级的相关性，比较不同Pfirrmann等级、层面椎间盘及不同年龄人员的 T1ρ值差异。结果飞行人员组T1ρ值较对照组低（t＝3．154， P＜0．01），两组椎间盘髓核 T1ρ值与Pfirrmann等级均呈显著负相关（r＝－0．901、－0．921，P＜0．01）；飞行人员组椎间盘退变等级以Ⅲ、Ⅳ级较多，对照组以Ⅰ、Ⅱ级较多（Z＝4．040， P＜0．01）；飞行人员组与对照组各 Pfirrmann等级 T1ρ值差异无统计学意义。飞行人员组与对照组各层面椎间盘髓核 T1ρ值差异无统计学意义（ P＞0．05）。飞行人员组与对照组椎间盘髓核T 1ρ值在30～39岁及≥40岁年龄段差异有统计学意义（ t＝4．438、4．646， P＜0．01），在＜30岁差异无统计学意义（ P＞0．05）。结论飞行人员椎间盘退变较对照组快，腰椎长期承受高载荷可能是导致椎间盘退变加速的重要因素。 T1ρ成像技术是评估飞行人员早期椎间盘退变的一种有效工具。

Objective To evaluate early intervertebral disc degeneration quantified by T1ρ‐and T2‐weighted magnetic resonance imaging （MRI）at 3 .0T in asymptomatic pilots compared with a health control group . Methods Total 69 volunteers were divided in two groups .Flying personnel group：34 asymptomatic male pilots . Control group：35 asymptomatic volunteers . Both sagittal conventional T2‐ and T1ρ‐weigted images were acquired at every examination of lumbar disc and uploaded to workstation .The sagittal T1ρmaps were reformatted for each of the disks and mean T1ρvalues of the central disk space nucleus pulposus were determined by FUNCTOOL software and generated pseudeo‐color images .The degenerative grade of each lumbar disc was assessed from T2‐weighted images according to Pfirrmann degenerative grade .The correlation between T1ρ value and degenerative grade was analysed . The correlation between T1ρ value and degenerative grade was analysed in flying personnel group and control group .The T1ρvalues were compared upon Pfirrmann degenerative grade ,varied intervertebral disks and age . Results The T1ρ value of the flying personnel group was significantly lower than that of the control group （t= 3 .154 , P〈 0 .01） .T1ρvalues significantly and negatively correlated with Pfirrmann grade in two groups （r= -0 .901 ,-0 .921 , P〈 0 .01） .The degenerative grades of flying personnel group mainly were grade Ⅲ and Ⅳ ,but control group were mainly on grade Ⅰ and Ⅱ（Z=4 .040 ,P〈0 .01） .The T1ρvalues upon Pfirrmann degenerative grade were not statistically significant between flying personnel and control groups .No significant differences were found between the T1ρ values upon intervertebral disks of groups （P〉0 .05） .The T1ρvalue comparisons for 30‐39 yr and ≥40 yr age ranges showed significant differences between flying personnel group and control group （t= 4 .438 ,4 .646 , P〈 0 .01） ,but for 〈 30 yr range （P〉 0 .05） . Conclusions Disc degeneration occurred on flying personnel is more seriously than the control group and the process of degeneration is more quickly .Long‐term high load on spine column of flying personnel may be the important reason of high load accelerating the degeneration .T1ρimaging technigue can be a valid clinical tool in quantitatively diagnosing early intervertebral disc degeneration in asymptomatic flying personnel .