定量磁敏感图对终末期肾病患者脑铁沉积的定量研究

Quantitative study of brain iron deposition in patients with end-stage renal disease by quantitative susceptibility mapping

目的:应用定量磁敏感图(quantitative susceptibility mapping,QSM)比较终末期肾病(end-stage renal disease,ESRD)患者和健康对照者大脑深部灰质核团的磁敏感值(magnetic susceptibility value,MSV),并分析ESRD患者MSV与蒙特利尔认知评估量表(montreal cognitive assessment,MoCA)评分的相关性,探讨QSM技术评估ESRD患者脑铁沉积的价值以及脑铁沉积对认知功能的影响。方法:招募南通大学附属医院25例ESRD患者及25例年龄性别相匹配的健康对照者,应用QSM技术测量每个人大脑深部灰质核团的MSV,应用Mann-Whitney U检验比较各核团MSV的差异,应用受试者工作特征(receiver operating characteristic,ROC)曲线分析评价其诊断效能,应用Spearman相关性分析评估ESRD患者MSV与MoCA评分的相关性。结果:ESRD患者双侧红核(red nucleus,RN)、黑质(substantia nigra,SN)、尾状核头部(caudate head,CA)、壳核(putamen,PU)的MSV大于健康对照者(P均<0.05)。双侧RN、SN、PU及CA的MSV可以区分ESRD患者与健康对照者,当右侧PU的MSV为0.085时,曲线下面积(area under the curve,AUC)最大,敏感性为67%,特异性为91%。ESRD患者右侧RN的MSV与语言能力、抽象能力呈负相关,左侧CA的MSV与注意力、语言能力呈负相关,左侧苍白球(globus pallidus,GP)的MSV和视觉空间与执行能力呈负相关(P均<0.05)。结论:QSM技术不仅可以定量评估ESRD患者脑内铁沉积,还可以分析ESRD患者脑内铁沉积对认知功能的影响。

Objective:This study aims to explore the effect of quantitative susceptibility mapping(QSM)in evaluating brain iron deposition in the patients with end-stage renal disease(ESRD)and the impact of iron deposition on cognitive function by comparing the magnetic susceptibility value(MSV)of the deep gray matter nuclei between the patients with ESRD and healthy controls,and analyzed the correlations between the MSVs of the patients with ESRD and the scores of the Montreal Cognitive Assessment(MoCA).Methods:Twenty-five patients with ESRD and 25 healthy controls who are age and sex-matched were recruited in this study.The MSVs of the deep gray matter nuclei of all the patients with ESRD and healthy controls were measured with QSM.The differences of the MSVs of the nuclei between the patients and controls were analyzed by the Mann-Whitney U test.The diagnostic efficacy of the MSVs was analyzed by the receiver operating characteristic(ROC)curve.The correlations between the MSVs of the patients and the scores of the MoCA were analyzed by Spearman correlation analysis.Results:In the patients with ESRD,the MSVs of bilateral red nucleus(RN),substantia nigra(SN),caudate head(CA)and putamen(PU)were higher than those in the controls(P<0.05 respectively).The MSVs of bilateral RN,SN,PU and CA can distinguish the patients from healthy controls.ROC analysis revealed that the cut-off values of PU MSV(0.085)provided the best combination of sensitivity(67%)and specificity(91%)to distinguish the ESRD patients from controls.In the patients with ESRD,the MSV of the right RN was negatively correlated with language ability and abstract ability,the left CA was negatively correlated with attention and language ability,and the left globus pallidus(GP)was negatively correlated with visuospatial and executive ability(P<0.05 respectively).Conclusion:In patients with ESRD,QSM not only can evaluate brain iron deposition quantitatively,but contribute to analyze the impact of iron deposition on cognitive function.