腰椎间盘退变软骨下骨及软骨终板灌注的DCE-MRI定量研究

DCE-MRI Quantitative Study of Vertebra Subchondral Bone and Cartilage Endplate Perfusion of Degenerated Intervertebral Discs

目的采用基于Extended Tofts linear模型动态对比增强MRI(DCE-MRI)定量研究椎间盘退变椎体软骨下骨(VSB)、软骨终板(CEP)的灌注。方法 18例受检者分别行腰椎常规检查及DCE-MRI。记录椎体头、尾侧VSB、CEP感兴趣区灌注参数Ktrans、Kep、Ve值。在腰椎正中矢状位T2WI确定椎间盘Pfirrmann分级。采用单因素方差分析(One-way ANOVA)与Newman-Keuls多重比较检验比较不同分级DCE-MRI各灌注参数值差异,以P<0.05为差异具有统计学意义。结果共纳入研究90个椎间盘。Pfirrmann 1级5个,占5.56%;2级27个,占30.00%;3级21个,占23.33%;4级32个,占35.56%;5级5个,占5.56%。头、尾侧VSB及头、尾侧CEP灌注参数从1~2级先上升,2~3级后下降,4~5级再上升后下降。不同Pfirrmann分级头侧VSB Ktrans值、Kep值、尾侧VSB Kep值、头侧CEP Kep值具有统计学意义(F值分别为2.701、5.036、2.724、2.714,P值均<0.05)。其中Pfirrmann 1级与2级、1级与4级、2级与3级、3级与4级头侧VSB Kep值、Pfirrmann 1级与4级尾侧VSB Kep值及Pfirrmann 2级与3级头侧CEP Kep值差异具有统计学意义(q值分别为4.560、5.059、3.425、4.305、3.996、4.256,P值均<0.05),余两组间VSB、CEP灌注参数值差异均无统计学意义(P值均>0.05)。结论 DCE-MRI定量技术显示在椎间盘退变中,VSB及CEP灌注在Pfirrmann 2级升高,3级降低,4级升高,最后在5级降低。

Objective To investigate vertebra subchondral bone and cartilage endplate perfusion of degenerated intervertebral discs by DCE-MRI technology based on Tofts linear model. Methods 18 participants underwent lumbar conventional and DCE-MRI examination. The perfusion parameters （ Ktrans, Kop, Ve） of cranial and caudal vertebral subchondral bone（VSB） and cartilage endplate（CEP） in the interest area were recorded. T2-weighted images in the lumbar median sagittal plane were used for Pfirrmann classification. One-way analysis of variance （ One-way ANOVA） with post-hoc tests （ Newman-Keuls Multiple Comparison Test） was employed to judge the difference of the DCE-MRI perfusion parameters among these grades, and P 〈 0.05 was considered statistically significant. Results In 90 intervertebral discs, there were 5 Pfirrmann I （5.56%）, 27 Pfirrmann Ⅱ （ 30.00% ）, 21 Pfirrmann Ⅲ （23.33%）, 32 Pfirrmann IV （35.56%）, and 5 Pfirrmann V （5.56%）. Each perfusion parameter of cranial, caudal VSB and cranial and caudal CEP increased at grade 1 - 2 and then decreased at grade 2 - 3, and then increased at grade 4 - 5 and finally decreased at grade 5. The cranial VSB Ktrans, Kop, caudal VSB Kep and cranial CEP Kep were statistically significant in different Pfirrmann grades by One-way ANOVA （F=2.701, 5.036, 2.724, 2.714, all P〈0. 05）. Except for the cranial VSB perfusion parameters Kep of Pfirrmann Ⅰ and Ⅱ, Pfirrmann Ⅰ and Ⅳ, Pfirrmann Ⅲ and Ⅱ , Pfirrmann Ⅲ and IV, the caudal VSB perfusion parameters Kep of Pfirrmann Ⅰ and Ⅳ, the cranial CEP Kop of Pfirrmann Ⅲ and Ⅱ（q = 4. 560, 5. 059, 3. 425, 4. 305, 3. 996, 4.256, all P 〈 0.05 ）, the other two different grades of perfusion parameters had no significant difference observed in VSB and CEP. Conclusion DCE-MRI quantitative techniques showed that VSB and CEP perfusion increased in the Pfirrmann grade 2, decreased in grade 3, increased in grade 4, and lastly decreased in the grade 5 in the intervertebral disc degeneration progress.