Objective:To compare the differences in blood oxygen level-dependent(BOLD)parameters following maternal hyperoxia between normal pregnancy and pregnancy in the rat model of gestational diabetes mellitus(GDM).Methods:G...Objective:To compare the differences in blood oxygen level-dependent(BOLD)parameters following maternal hyperoxia between normal pregnancy and pregnancy in the rat model of gestational diabetes mellitus(GDM).Methods:GDM was induced by high-fat and sucrose diet(HFS)combined with an intraperitoneal injection of streptozotocin(STZ).On embryonic day 19(E19),the two groups of pregnant rats were imaged using a 7.0-T animal MRI scanner.TurboRARE was initially used to localize the fetoplacental units(FPUs).Next,multiple gradient echo BOLD was performed during the air and oxygen inhalation periods.T2^(*)map was then generated,and the baseline T2^(*)and absolute changes in T2^(*)value(ΔT2^(*),difference between T2^(*)oxy and T2^(*)air)were calculated.Following the MRI scan,the placentas and fetuses were aseptically stripped,weighed,and immunostained.Results:Nine rats were used in this study.After maternal oxygen inhalation,T2^(*)increased significantly in all subjects in both groups.TheΔT2^(*)for the placenta(5.97 vs.7.81 msec;P=0.007)and fetal brain(2.23 vs.3.97 msec;P=0.005)differed significantly between the GDM and control groups.Histochemical detection of placental glycogen content and inflammatory cytokines(IL-6 and TNF-α)showed significantly higher levels in the GDM than in the normal placenta.Conclusions:BOLD-MRI revealed abnormalities in the fetoplacental response to maternal hyperoxygenation in rats with GDM.We believe that this approach can potentially be used to evaluate placental dysfunction and assess the state of the fetus during pregnancy with GDM.展开更多
目的针对目前缺少对脑肿瘤患者客观的认知损伤评价标准,本文提出基于静息态功能磁共振数据的脑复杂度分析方法。方法首先对24位肿瘤患者与18位健康志愿者的BOLD-f MRI图像分别进行预处理,再求取全脑平均样本熵值及全脑体素样本熵图,然...目的针对目前缺少对脑肿瘤患者客观的认知损伤评价标准,本文提出基于静息态功能磁共振数据的脑复杂度分析方法。方法首先对24位肿瘤患者与18位健康志愿者的BOLD-f MRI图像分别进行预处理,再求取全脑平均样本熵值及全脑体素样本熵图,然后求取以肿瘤部位为感兴趣区域(region of interest,ROI)的功能连接和互样本熵值对比分析。结果健康志愿者样本熵值明显高于肿瘤患者(F=15.907,P=0.000),互样本熵值与功能连接呈负相关关系,并且左额或左颞有脑肿瘤的患者在左额、左颞、楔叶的功能脑区与健康志愿者相比有明显差异,该研究结果与临床诊断数据较为一致。结论提出一种基于样本熵的脑复杂度分析方法,发现肿瘤会影响大脑的复杂度,肿瘤级别升高导致大脑复杂度的降低,该方法所得结果能够作为评定肿瘤级别的量化参数之一。展开更多
The work of this paper analyzes the performance of Sensitivity Encoding (SENSE) through actual data sets and determines the problem of computational efficiency. It corrects the error of the detection signal through th...The work of this paper analyzes the performance of Sensitivity Encoding (SENSE) through actual data sets and determines the problem of computational efficiency. It corrects the error of the detection signal through the calibration function of the percentage signal change, and uses the three-dimensional sensor image reconstruction technology to calibrate the sensitivity of the blood to the magnetic change, enhances the sensitivity of the magnetic susceptibility gradient, and reduces the scanning time of the MRI experiment. The actual data set handles the image resolution. The performance and experimental results of SENSE are analyzed through actual data sets.展开更多
This paper presents a theoretical elaboration aimed to explain the correlation found between a new rs-fMRI modality and electrophysiology and nuclear medicine neuroimaging, performed to localize epileptogenic brain ar...This paper presents a theoretical elaboration aimed to explain the correlation found between a new rs-fMRI modality and electrophysiology and nuclear medicine neuroimaging, performed to localize epileptogenic brain areas. We present in detail the clinical history, and electrophysiological and neuroimaging results of one child with intractable epilepsy, who was submitted for Phase-1 work-up as candidate for epilepsy surgery. The patient underwent a thorough workup including video-telemetry, ictal and interictal nuclear medicine imaging, resting-state fMRI, EEG-fMRI, intracranial electroencephalography (ECoG), deep electrode implantation, and resective surgery. Electrophysiology and neuroimaging findings were concordant with findings provided by the resting-state mean signal. The patient became seizure-free after the resection of the target area. A theoretical discussion is provided that considers the presence of a stable BOLD effect explaining the findings of the observed resting-state mean signal. This stable BOLD is linked to low regional metabolism usually present in the epileptogenic area during interictal periods, coupled with low oxygen extraction. Low oxygen extraction leaves more oxygen for the draining venule and consequently increases the BOLD signal.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
基金National Natural Science Foundation of China(81571460)
文摘Objective:To compare the differences in blood oxygen level-dependent(BOLD)parameters following maternal hyperoxia between normal pregnancy and pregnancy in the rat model of gestational diabetes mellitus(GDM).Methods:GDM was induced by high-fat and sucrose diet(HFS)combined with an intraperitoneal injection of streptozotocin(STZ).On embryonic day 19(E19),the two groups of pregnant rats were imaged using a 7.0-T animal MRI scanner.TurboRARE was initially used to localize the fetoplacental units(FPUs).Next,multiple gradient echo BOLD was performed during the air and oxygen inhalation periods.T2^(*)map was then generated,and the baseline T2^(*)and absolute changes in T2^(*)value(ΔT2^(*),difference between T2^(*)oxy and T2^(*)air)were calculated.Following the MRI scan,the placentas and fetuses were aseptically stripped,weighed,and immunostained.Results:Nine rats were used in this study.After maternal oxygen inhalation,T2^(*)increased significantly in all subjects in both groups.TheΔT2^(*)for the placenta(5.97 vs.7.81 msec;P=0.007)and fetal brain(2.23 vs.3.97 msec;P=0.005)differed significantly between the GDM and control groups.Histochemical detection of placental glycogen content and inflammatory cytokines(IL-6 and TNF-α)showed significantly higher levels in the GDM than in the normal placenta.Conclusions:BOLD-MRI revealed abnormalities in the fetoplacental response to maternal hyperoxygenation in rats with GDM.We believe that this approach can potentially be used to evaluate placental dysfunction and assess the state of the fetus during pregnancy with GDM.
文摘目的针对目前缺少对脑肿瘤患者客观的认知损伤评价标准,本文提出基于静息态功能磁共振数据的脑复杂度分析方法。方法首先对24位肿瘤患者与18位健康志愿者的BOLD-f MRI图像分别进行预处理,再求取全脑平均样本熵值及全脑体素样本熵图,然后求取以肿瘤部位为感兴趣区域(region of interest,ROI)的功能连接和互样本熵值对比分析。结果健康志愿者样本熵值明显高于肿瘤患者(F=15.907,P=0.000),互样本熵值与功能连接呈负相关关系,并且左额或左颞有脑肿瘤的患者在左额、左颞、楔叶的功能脑区与健康志愿者相比有明显差异,该研究结果与临床诊断数据较为一致。结论提出一种基于样本熵的脑复杂度分析方法,发现肿瘤会影响大脑的复杂度,肿瘤级别升高导致大脑复杂度的降低,该方法所得结果能够作为评定肿瘤级别的量化参数之一。
文摘The work of this paper analyzes the performance of Sensitivity Encoding (SENSE) through actual data sets and determines the problem of computational efficiency. It corrects the error of the detection signal through the calibration function of the percentage signal change, and uses the three-dimensional sensor image reconstruction technology to calibrate the sensitivity of the blood to the magnetic change, enhances the sensitivity of the magnetic susceptibility gradient, and reduces the scanning time of the MRI experiment. The actual data set handles the image resolution. The performance and experimental results of SENSE are analyzed through actual data sets.
文摘This paper presents a theoretical elaboration aimed to explain the correlation found between a new rs-fMRI modality and electrophysiology and nuclear medicine neuroimaging, performed to localize epileptogenic brain areas. We present in detail the clinical history, and electrophysiological and neuroimaging results of one child with intractable epilepsy, who was submitted for Phase-1 work-up as candidate for epilepsy surgery. The patient underwent a thorough workup including video-telemetry, ictal and interictal nuclear medicine imaging, resting-state fMRI, EEG-fMRI, intracranial electroencephalography (ECoG), deep electrode implantation, and resective surgery. Electrophysiology and neuroimaging findings were concordant with findings provided by the resting-state mean signal. The patient became seizure-free after the resection of the target area. A theoretical discussion is provided that considers the presence of a stable BOLD effect explaining the findings of the observed resting-state mean signal. This stable BOLD is linked to low regional metabolism usually present in the epileptogenic area during interictal periods, coupled with low oxygen extraction. Low oxygen extraction leaves more oxygen for the draining venule and consequently increases the BOLD signal.
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。
