中文摘要：

目的运用DTI初步探讨无创评价活体椎间盘纤维环退变。方法选择2010年9月至2011年3月腰椎门诊就诊行腰椎MR检查患者，排除脊柱畸形、肿瘤及相关手术患者，共纳入研究对象88例，年龄16～63岁，平均（37±13）岁。对研究对象进行快速自旋回波及平面回波成像。剔除磁敏感重的图像，共获得428个椎间盘，测量其平均扩散系数（MD）、各向异性分数（FA）并获得其纤维环成像图，根据纤维环示踪图（FT）图形态学改变，对纤维环进行分型并测量其MD和FA，并进行比较。数据资料为非正态分布，以四分位间距及中位数表示。采用SPSS11．0软件包，χ2检验进行统计学分析。结果运用纤维环示踪技术每个椎间盘均可得到纤维环成像图，且不同Pfirrmann级别其纤维环类型不同，纤维环分型与Pfirrmann分级密切相关：规则型FT图135个，其中PfirrmannⅡ级（92个）比例最高，占68．15％；杂乱型纤维环FT图195个，以PfirrmannⅢ（93个）、Ⅳ级（30个）为主，占63．07％；团块型纤维环兀’图98个，以PfirrmannIV（39个）、Ⅴ级（43个）为主，占83．68％，差异具有统计学意义（Mantel—Haenszelχ2=检验，）（χ2=183．90，P〈0．01）。完整型FA值为0．32（0．29-0．35），MD值为12．40（11．50-13．20）×10^-10mm^2／s；杂乱型FA值为0．35（0．33～0．38），MD值为11．10（9．92-12．00）×10^-10mm^2／s；团块型FA值为0．54（0．46～0．62），MD值为6．30（5．03～7．72）×10^-10mm^2／s。纤维环结构越杂乱，其MD值越低，FA值越高，差异具有统计学意义（Kruskal-Wallis秩和检验，χ2值分别为219．74、243．88，P值均〈0．01）。结论DTI可无创性评估活体椎间盘结构变化，MD值及FA值有助于评价椎间盘退变程度。

英文摘要：

Objective To evaluate the earlier changes of degeneration discs in vivo using magnetic resonance diffusion tensor imaging （DTI）. Methods From September 2010 to March 2011, 88 consecutive outpatients [ age 16-63 years, mean age （37 ± 13 ） years ] were enrolled in this study. The excluded criteria were as follows： spinal deformity, spinal tumors and post-operation of spine. The mean diffusion （MD） and fractional anisotropy （FA） values on DTI images of 428 intervertebral discs which without susceptibility artifacts were measured. Fiber track （FT） images of annulus of intervertebral discs were analyzed. MD and FA were also measured on FT. The quartile and median were used to record the non- normal distribution dates. The Chi-square test statistic was applied by SPSS11.0 software package. Results Annulus fibrosis type had closely related to the Pfirrmann grading. Three types were divided based on FT charts of degenerated intervertebral disc. Intact type was noted in 135 discs, Pfirrmann Ⅱ level has a high percentage（92 discs,68. 15% ） in this type; Scrambled type was noted in 195 discs, Pfirrmann ⅢandⅣlevel were accounted for 63.07% （ 123 discs） ;Conglomerate type was noted in 98 discs, the Pfirrmann ⅣandⅤlevel were accounted for 83.68% （ 82 discs） （ Mantel-Haenszel test, χ = 183.90, P 〈 0.01 ）.Different annulus types had different MD and FA values. The median （range）of FA of complete, messy and clumps type fibrous ring were 0. 32 （ 0. 29-0. 35 ） , 0. 35 （ 0. 33-0. 38 ）, 0. 54 （ 0. 46-0. 62 ） . The corresponding median （range） of MD were 12.40 （ 11.50-13.20 ） × 10^- 10, 11.10 （ 9.92-12. 00） × 10^10 , 6. 30（5.03-7.72） ×10^ -10 mm^2/s. Scrambled annulus fibers had lower MD values and higher FA values, which had significant difference（χ 2=219.74,243.88, P〈0.01）. Conclusions DTI is a non-invasive method to assess intervertebral disc structural changes in vivo. MD and FA values are helpful to evaluate the intervertebral disc degen