目的利用MR磁敏感加权成像(SWI)测定脑静脉血相位值(phase值)、观察梗死病灶周围静脉改变,评价脑梗死后的缺氧状态及局部脑氧代谢改变。方法选择我院神经内科住院治疗的36例急性脑梗死患者(脑梗死组)及25例头颅MRI检查正常者(对照组)作...目的利用MR磁敏感加权成像(SWI)测定脑静脉血相位值(phase值)、观察梗死病灶周围静脉改变,评价脑梗死后的缺氧状态及局部脑氧代谢改变。方法选择我院神经内科住院治疗的36例急性脑梗死患者(脑梗死组)及25例头颅MRI检查正常者(对照组)作为研究对象。所有研究对象均行MRI检查,其中梗死患者14d内行MRI检查。MRI检查包括T1W、T2W、DWI及SWI检查。按梗死部位分基底核区及侧脑室旁亚组(21例),脑叶亚组(7例),桥脑亚组(8例);按梗死时间分为第1~7天亚组(17例)和第8~14天亚组(19例)。测量对照组及脑梗死组上矢状窦和直窦p ha s e值,测量梗死病灶体积,观察病灶周围静脉,进行美国国立卫生研究院卒中量表(NIHSS)评分。结果脑梗死组直窦phase值(2574.91±223.20)低于对照组(2908.49±207.56),差异有统计学意义(P<0.01);基底核区及侧脑室旁、脑叶和桥脑亚组直窦phase值(2523.00±215.80、2668.19±229.66、2629.55±224.79)均低于对照组,差异均有统计学意义(均P<0.05);脑叶亚组上矢状窦phase值(2205.09±65.73)高于基底核区及侧脑室亚组、桥脑亚组、对照组(2126.55±62.16、2137.24±51.31、2112.94±48.81),差异均有统计学意义(均P<0.05);脑梗死组中发现梗死病灶周围不同程度的静脉扩张21例,其中第1~7天亚组13例,第8~14天亚组8例;Spearman相关性分析提示病灶周围静脉扩张与梗死体积及梗死时间相关(均P<0.05)。结论 SWI能定量测定静脉血phase值,发现梗死灶周围静脉扩张,为临床无创性评价梗死区域脑组织缺氧及局部脑组织血氧代谢提供有价值的参考,有助于急性脑梗死的规范治疗。展开更多
AIM:To evaluate neurovascular uncoupling(NVU)associated with low grade gliomas(LGG)using blood oxygen level dependent(BOLD)cerebrovascular reactivity mapping.METHODS:Seven patients with low grade gliomas referred by n...AIM:To evaluate neurovascular uncoupling(NVU)associated with low grade gliomas(LGG)using blood oxygen level dependent(BOLD)cerebrovascular reactivity mapping.METHODS:Seven patients with low grade gliomas referred by neurosurgeons for presurgical mapping were included in this pilot study.Cerebrovascular reactivity(CVR)mapping was performed by acquiring BOLD images while patients performed a block-design breath-hold(BH)hypercapnia task.CVR mapping was expressed as BOLD percentage signal change(PSC)from baseline associated with performance of the BH hypercapnia task.Standard T2*Dynamic Susceptibility Contrast perfusion imaging was performed and relative cerebral blood volume(rCBV)and relative cerebral blood flow(rCBF)maps were generated.Structural T1 weighted MR images were also acquired.A correlation analysis between intratumoral normalized(via ratio with contralateral homologous regions)BOLD BH PSC[referred to as(nCVR)]and intratumoral normalized resting state rCBV(rCBF)values(i.e.,nCBV and nCBF,respectively)was performed.RESULTS:No significant correlation was seen between the normalized BOLD BH PSC(i.e.,nCBV)and nCBV or nCBF.However,the average nCVR(median=0.50,z=-2.28,P=0.01)was significantly less than 1.0,indicating abnormally reduced vascular responses in the tumor regions relative to normal contralesional homologous regions,whereas the average nCBV(median=0.94,z=-0.92,P=0.375)and nCBF(median=0.93,z=-1.16,P=0.25)were not significantly higher or lower than 1.0,indicating iso-perfusion in the tumor regions relative to normal contralesional homologous regions.These findings suggest that in LGG,hyperperfusion that is seen in high grade gliomas is not present,but,nevertheless,abnormally decreased regional CVR is present within and adjacent to LGG.Since the patients all demonstrated at least some residual function attributable to the cortical regions of impaired CVR,but were incapable of producing a BOLD response in these regions regardless of the tasks performed,such regionally decreased CVR is indicative of NVU.The low nCVR ratios indicate high prevalence of NVU in this LGG cohort,which is an important consideration in the interpretation of clinical presurgical mapping with functional magnetic resonance(MR)imaging.CONCLUSION:Our preliminary study shows that BH CVR mapping is clinically feasible and demonstrates an unexpectedly high prevalence of NVU in patients with LGG.展开更多
利用功能磁共振成像(fMRI)进行脑功能研究是目前的一个热点,本文以逻辑计算为认知任务,利用fMRI进行数据采集,通过SPM软件分析得到激活脑区,提取感兴趣区(Regions of interest,ROI)的平均BOLD信号(Average-BOLD),并利用主成分分析(Princ...利用功能磁共振成像(fMRI)进行脑功能研究是目前的一个热点,本文以逻辑计算为认知任务,利用fMRI进行数据采集,通过SPM软件分析得到激活脑区,提取感兴趣区(Regions of interest,ROI)的平均BOLD信号(Average-BOLD),并利用主成分分析(Principal component analysis,PCA)方法提取ROI内BOLD信号(PCA-BOLD),通过Average-BOLD、PCA-BOLD信号与实验设计的逻辑任务曲线进行比较,认为PCA-BOLD信号可以更好的作为fMRI激活脑区的定量评估指标,用来衡量ROI激活强度,并进行脑功能基础研究。展开更多
文摘目的利用MR磁敏感加权成像(SWI)测定脑静脉血相位值(phase值)、观察梗死病灶周围静脉改变,评价脑梗死后的缺氧状态及局部脑氧代谢改变。方法选择我院神经内科住院治疗的36例急性脑梗死患者(脑梗死组)及25例头颅MRI检查正常者(对照组)作为研究对象。所有研究对象均行MRI检查,其中梗死患者14d内行MRI检查。MRI检查包括T1W、T2W、DWI及SWI检查。按梗死部位分基底核区及侧脑室旁亚组(21例),脑叶亚组(7例),桥脑亚组(8例);按梗死时间分为第1~7天亚组(17例)和第8~14天亚组(19例)。测量对照组及脑梗死组上矢状窦和直窦p ha s e值,测量梗死病灶体积,观察病灶周围静脉,进行美国国立卫生研究院卒中量表(NIHSS)评分。结果脑梗死组直窦phase值(2574.91±223.20)低于对照组(2908.49±207.56),差异有统计学意义(P<0.01);基底核区及侧脑室旁、脑叶和桥脑亚组直窦phase值(2523.00±215.80、2668.19±229.66、2629.55±224.79)均低于对照组,差异均有统计学意义(均P<0.05);脑叶亚组上矢状窦phase值(2205.09±65.73)高于基底核区及侧脑室亚组、桥脑亚组、对照组(2126.55±62.16、2137.24±51.31、2112.94±48.81),差异均有统计学意义(均P<0.05);脑梗死组中发现梗死病灶周围不同程度的静脉扩张21例,其中第1~7天亚组13例,第8~14天亚组8例;Spearman相关性分析提示病灶周围静脉扩张与梗死体积及梗死时间相关(均P<0.05)。结论 SWI能定量测定静脉血phase值,发现梗死灶周围静脉扩张,为临床无创性评价梗死区域脑组织缺氧及局部脑组织血氧代谢提供有价值的参考,有助于急性脑梗死的规范治疗。
文摘AIM:To evaluate neurovascular uncoupling(NVU)associated with low grade gliomas(LGG)using blood oxygen level dependent(BOLD)cerebrovascular reactivity mapping.METHODS:Seven patients with low grade gliomas referred by neurosurgeons for presurgical mapping were included in this pilot study.Cerebrovascular reactivity(CVR)mapping was performed by acquiring BOLD images while patients performed a block-design breath-hold(BH)hypercapnia task.CVR mapping was expressed as BOLD percentage signal change(PSC)from baseline associated with performance of the BH hypercapnia task.Standard T2*Dynamic Susceptibility Contrast perfusion imaging was performed and relative cerebral blood volume(rCBV)and relative cerebral blood flow(rCBF)maps were generated.Structural T1 weighted MR images were also acquired.A correlation analysis between intratumoral normalized(via ratio with contralateral homologous regions)BOLD BH PSC[referred to as(nCVR)]and intratumoral normalized resting state rCBV(rCBF)values(i.e.,nCBV and nCBF,respectively)was performed.RESULTS:No significant correlation was seen between the normalized BOLD BH PSC(i.e.,nCBV)and nCBV or nCBF.However,the average nCVR(median=0.50,z=-2.28,P=0.01)was significantly less than 1.0,indicating abnormally reduced vascular responses in the tumor regions relative to normal contralesional homologous regions,whereas the average nCBV(median=0.94,z=-0.92,P=0.375)and nCBF(median=0.93,z=-1.16,P=0.25)were not significantly higher or lower than 1.0,indicating iso-perfusion in the tumor regions relative to normal contralesional homologous regions.These findings suggest that in LGG,hyperperfusion that is seen in high grade gliomas is not present,but,nevertheless,abnormally decreased regional CVR is present within and adjacent to LGG.Since the patients all demonstrated at least some residual function attributable to the cortical regions of impaired CVR,but were incapable of producing a BOLD response in these regions regardless of the tasks performed,such regionally decreased CVR is indicative of NVU.The low nCVR ratios indicate high prevalence of NVU in this LGG cohort,which is an important consideration in the interpretation of clinical presurgical mapping with functional magnetic resonance(MR)imaging.CONCLUSION:Our preliminary study shows that BH CVR mapping is clinically feasible and demonstrates an unexpectedly high prevalence of NVU in patients with LGG.
文摘利用功能磁共振成像(fMRI)进行脑功能研究是目前的一个热点,本文以逻辑计算为认知任务,利用fMRI进行数据采集,通过SPM软件分析得到激活脑区,提取感兴趣区(Regions of interest,ROI)的平均BOLD信号(Average-BOLD),并利用主成分分析(Principal component analysis,PCA)方法提取ROI内BOLD信号(PCA-BOLD),通过Average-BOLD、PCA-BOLD信号与实验设计的逻辑任务曲线进行比较,认为PCA-BOLD信号可以更好的作为fMRI激活脑区的定量评估指标,用来衡量ROI激活强度,并进行脑功能基础研究。
