MR体素内不相干运动弥散加权成像评估腰椎间盘退变程度

MR intravoxel incoherent motion-diffusion weighted imaging for evaluation on degree of lumbar disc degeneration

目的观察MR体素内不相干运动-弥散加权成像(IVIM-DWI)定量评估腰椎间盘退变程度的价值。方法对90例下腰痛患者采集共450个腰椎间盘常规MRI及IVIM-DWI,评估各椎间盘Pfirrmann分级,比较不同Pfirrmann分级椎间盘之间IVIM-DWI定量参数表观弥散系数(ADC)、慢速弥散系数(D)、快速弥散系数(D*)及灌注分数(f)的差异;采用有序logistic回归分析及受试者工作特征(ROC)曲线评价IVIM-DWI定量参数诊断腰椎间盘退变Pfirrmann分级的效能。结果450个椎间盘中,21个PfirrmannⅠ级,168个Ⅱ级,152个Ⅲ级,87个Ⅳ级,22个Ⅴ级。PfirrmannⅠ与Ⅱ级之间髓核ADC、D值及前纤维环ADC,Ⅱ与Ⅲ级间髓核ADC、D和f值及前、后纤维环ADC、D值,Ⅲ与Ⅳ级间髓核ADC、D、f值、前纤维环ADC、D值及后纤维环ADC,Ⅳ与Ⅴ级间髓核ADC、D值及后纤维环D值差异均有统计学意义(P均<0.05);相邻Pfirrmann分级间其余IVIM-DWI定量参数差异均无统计学意义(P均>0.05)。髓核ADC(OR=1.879)及D值(OR=2.212)均为腰椎间盘退变Pfirrmann分级的相关因素(P均<0.001)。髓核ADC及D值评估Pfirrmann分级的曲线下面积为0.80~0.92。结论IVIM-DWI可有效定量评估椎间盘退变程度。

Objective To explore the value of MR intravoxel incoherent motion-diffusion weighted imaging(IVIM-DWI)for evluating the degree of of lumbar disc degeneration.Methods Conventional lumbar MRI and IVIM-DWI of 90 patients with 450 lumbar intervertebral discs were collected,and Pfirrmann grading of each disc was evaluated.The apparent diffusion coefficient(ADC),slow diffusion coefficient(D),fast diffusion coefficient(D*)and perfusion fraction(f)of intervertebral discs were compared among different Pfirrmann grades.Ordered logistic regression analysis and receiver operating characteristic(ROC)curve were used to observe the efficacy of IVIM-DWI quantitative parameters for evaluating Pfirrmann grades of lumbar disc degeneration.Results Among 450 intervertebral discs,21 were Pfirrmann gradeⅠ,168 were gradeⅡ,152 were gradeⅢ,87 were gradeⅣand 22 were gradeⅤ.Significant differences of ADC,D values of nucleus pulposus and ADC of anterior annulus fibrosus between Pfirrmann gradeⅠandⅡ,ADC,D,f values of nucleus pulposus,ADC and D values of anterior and posterior annulus fibrosus between gradeⅡandⅢ,ADC,D and f values of nucleus pulposus,ADC and D values of anterior annulus fibrosus,and ADC of posterior annulus fibrosus between gradeⅢandⅣ,ADC and D values of nucleus pulposus and D values of posterior annulus fibrosus between gradeⅣandⅤwere found(all P<0.05),while there was no significant difference of other IVIM-DWI quantitative parameters between adjacent Pfirrmann grades(all P>0.05).ADC(OR=1.879)and D(OR=2.212)values of nucleus pulposus were both related factors for Pfirrmann grades of lumbar disc degeneration(both P<0.001).The area under the curve of ADC and D values of nucleus pulposus for diagnosing different Pfirrmann grades were 0.80—0.92.Conclusion IVIM-DWI could effectively quantitatively evaluate the degree of lumbar disc degeneration.