T2 mapping技术在腰椎间盘退变评估中的应用价值

The application value of T2 mapping technique in the assessment of lumbar disc degeneration

目的：探讨T2 mapping技术评估腰椎间盘退变的应用价值。材料与方法 ：对33例经临床诊断为椎间盘退变的病例行腰椎磁共振常规序列和T2 mapping扫描。椎间盘退变分级采用Pfirrmann标准。基于矢状位T2 mapping伪彩图,采用手动勾画感兴趣区法,分别测量椎间盘前后纤维环及髓核的T2值。采用单因素方差分析分别比较不同Pfirrmann等级椎间盘的前后纤维环及髓核的T2值差异。Pfirrmann等级与椎间盘不同部位T2值的相关性采用Spearman相关分析评估。结果：前后纤维环Ⅰ~Ⅴ级的T2值差异无统计学意义（前纤维环,P=0.233;后纤维环,P=0.906）。髓核Ⅰ~Ⅴ级的T2值差异有统计学意义（P=0.000）。两两比较后发现,Ⅱ~Ⅲ级、Ⅲ~Ⅳ级的T2值差异有统计学意义（Ⅱ~Ⅲ级,P=0.000;Ⅲ~Ⅳ级,P=0.008）。而Ⅰ~Ⅱ级、Ⅳ~Ⅴ级的T2值差异无统计学差异（Ⅰ~Ⅱ级,P=0.357;Ⅳ~Ⅴ级,P=0.489）。Spearman相关分析结果显示,髓核T2值与Pfirrmann分级呈明显负相关（r=-0.765,P=0.000）,前纤维环T2值与Pfirrmann分级呈弱负相关（r=-0.166,P=0.036）,而后纤维环T2值与Pfirrmann分级不相关（r=0.051,P=0.521）。结论 ：T2 mapping技术可定量显示不同等级椎间盘的不同组织结构间的T2值差异,为临床定量化诊断椎间盘退变提供参考。

Objective： To evaluate the application value of T2 mapping technique in the assessment of lumbar disc degeneration. Materials and Methods： 33 cases diagnosed as lumbar disc degeneration underwent lumbar routine magnetic resonance imaging and T2 mapping scanning. All their intervertebral discs（IVDs） were graded by Pfirrmann scale. T2 values of the anterior annulus fibrosus（AAF）, the nucleus pulposus（NP） and the posterior annulus fibrosus（PAF） were measured manually on the sagittal T2 map. ANOVA analysis was used to compare the differences of T2 values at the AAF, NP and PAF of degenerated IVD with different Pfirrmann grades. The correlation between T2 values and Pfirrmann grades of the IVDs was evaluated by Spearman analysis. Results： No significant differences were found about T2 values of AAF or PAF at different Pfirrmann grades（AAF, P=0.233; PAF, P=0.906）, while significant difference was found about T2 values of NP at different Pfirrmann grades（P=0.000）. After multiple comparisons, T2 values of Pfirrmann Ⅱ~Ⅲ and Pfirrmann Ⅲ~Ⅳ showed statistical differences（Pfirrmann Ⅱ~Ⅲ, P=0.000; Pfirrmann Ⅲ~Ⅳ, P=0.008）. But T2 values of Pfirrmann Ⅰ~Ⅱ and Pfirrmann Ⅲ~Ⅴ had no statistical differences（Pfirrmann Ⅰ~Ⅱ, P=0.357; Pfirrmann Ⅳ~Ⅴ, P=0.489）. Significant negative correlation was found between T2 values of NP and Pfirrmann grades（r=-0.765, P=0.000）, while only poor correlation was found between T2 values of AAF and Pfirrmann grades（r=-0.166, P=0.036）, and no correlation between T2 values of PAF and Pfirrmann grades（r=0.051,P=0.521）. Conclusion： T2 mapping technique could quantitatively demonstrate the differences of T2 values between the different structures of IVDs at different Pfirrmann grades, which provided evidence for clinical quantitative diagnosis of the IVD degeneration.