扩散峰度成像在原发性胼胝体变性中的诊断价值

Diagnostic Value of Diffusion Kurtosis Imaging in Primary Corpus Callosum Degeneration

目的探讨扩散峰度成像(DKI)在原发性胼胝体变性(Marchiafava-Bignami综合征,MBD)中的诊断价值。方法回顾性分析20例经临床确诊的MBD患者(MBD组)及20名健康志愿者(对照组)的颅脑磁共振常规序列及DKI序列资料,总结MBD患者的MRI表现及DKI表现,并进一步定量分析两组平均峰度(MK)值及分数各向异性(FA)值的差异。采用两独立样本t检验对两组的MK值及FA值进行统计学分析,P<0.05为差异具有统计学意义;绘制MK值及FA值的受试者工作特征曲线(ROC),评价其对MBD的诊断效能。结果MBD在常规MRI上急性型表现为胼胝体肿胀,呈膨胀性改变,以膝部为著,T1WI呈等或低信号,T2WI呈高信号,FLAIR呈高信号,DWI呈明显高信号,典型表现为"三明治征";中间型表现与急性型相仿,胼胝体肿胀程度较急性型略轻微;慢性型表现为胼胝体萎缩变薄,其内可见条带状、小囊状长T1、长T2信号,可伴有脑萎缩、脑白质脱髓鞘改变。MBD组及对照组MK值、FA值差异具有统计学意义,MK值及FA值的ROC曲线下面积分别为0.95、0.86,MK值的敏感度及特异度分别为94.1%、88.8%;FA值的敏感度及特异度为93.2%、85.4%。结论不同类型MBD在MRI上具有其特征性表现,典型表现为"三明治征";DKI中MK值较FA值具有更高的诊断效能;DKI可以作为常规MRI序列的有利补充,减少MBD误诊率,量化分析MBD患者的病情严重程度,进一步指导临床治疗,并可对患者的预后进行随访和评估。

Objective To investigate the diagnostic value of diffusion kurtosis imaging(DKI)in primary corpus callosum(Marchiafava-Bignami syndrome,MBD).Methods Retrospective analysis of 20 cases of clinically diagnosed MBD patients and 20 healthy volunteers with brain magnetic resonance sequence and DKI sequence data,divided into MBD group and control group,analysis and summary of MRI imaging findings of MBD patients And DKI performance,and further quantitative analysis of the difference between the two groups of MK and FA values.The MK and FA values of the two groups were statistically analyzed by independent sample t test.P<0.05 was considered statistically significant.The ROC curves of MK and FA values were drawn to evaluate the diagnostic efficacy of MBD disease.Results MBD on conventional MRI in acute disease showed swollen corpus callosum with dilated changes,with the genu as the focus,T1WI showed equal or low signal,T2WI showed high signal,FLAIR showed high signal,DWI showed high signal,and DWI showed obvious high signal,typical appearance of the"Sandwich sign".The appearance of the intermediate type was similar to the acute type,and the splenium of the corpus callosum is slightly less expanded compared to the acute type.The chronic type is characterized by thinning of the corpus callosum.There are brain atrophic and white matter demyelination changes.The difference between MK value and FA value of MBD group and control group was statistically significant.The area under ROC curve of MK value and FA value was 0.95 and 0.86,and the sensitivity and specificity of MK value was 94.1%and 88.8%,respectively.The FA value sensitivity and specificity were 93.2%and 85.4%.Conclusion Different types of MBD have their characteristic features on MRI,and the typical manifestation is the"sandwich sign".The MK value in DKI has a higher diagnostic efficiency than the FA value.DKI can be used as a beneficial supplement to conventional MRI sequences to reduce the rate of MBD misdiagnosis,quantitative analysis of the severity of MBD patients,further guidance of clinical treatment,,follow-up and evaluation of the patients’prognosis.