将扩散干涉光谱（iDWS）技术与光外差检测方法和扩散散斑衬比分析方法相结合，提出了一种扩散相干散斑成像检测方法，并搭建了实验系统。该系统能有效地提高无创检测局部脑血流量（rCBF）的信噪比和检测精度，仿体流速实验结果表明，其相对血流指数与实际流速具有较好的线性度，在源-探距离为6~12 mm范围内线性相关系数均值为0.9881±0.0005。该检测方法可以区分不同目标区域的流速变化，管径为4.8 mm时相对误差为2.04%，结合血管管径测量方法可实现流速和流量的有效监测。通过在体实验和袖带加压实验，证明系统可以检测到活体rCBF的流速信息，且在有效测量流速范围内有较好的检测准确度。

Based on the laser speckle contrast imaging (LSCI) and the multiscale entropy (MSE), we study in this work the blood flow dynamics at the levels of cerebral veins and the surrounding network of microcerebral vessels. We discuss how the phenylephrine-related acute peripheral hypertension is reflected in the cerebral circulation and show that the observed changes are scale-dependent, and they are significantly more pronounced in microcerebral vessels, while the macrocerebral dynamics does not demonstrate authentic inter-group distinctions. We also consider the permeability of blood-brain barrier (BBB) and study its opening caused by sound exposure. We show that alterations associated with the BBB opening can be revealed by the analysis of blood flow at the level of macrocerebral vessels.

采用传统的热稀释法和指示剂稀释法测量脑血流参数（cerebral blood flow，CBF）需要导管插植和定时采血，会对机体造成一定的损伤。本文针对上述测量方法存在的有创且操作复杂等问题，提出了一种基于Fick定律和朗伯比尔定律的快速、无创脑血流测量方法。该方法基于脉搏色素法/近红外光谱术（PDD-NIRS）技术，选用吲哚氰绿（indocyanine green,ICG）作为指示剂，通过对脑部和动脉ICG引入量的计算得到CBF。为验证模型的正确性，采用成年白兔进行了动物实验。对白兔静脉快速推注ICG色素，应用PDD-NIRS方法测量其CBF，然后计算出CBF值。 实验显示；应用PDD-NIRS方法测得的CBF相对误差为2%~4%，验证了该方法测量CBF的可行性；临床对比测量显示其平均误差满足临床诊断要求。该方法为临床诊断心脑血管疾病以及临床脑血流监护提供了有益的参考手段。

临床上脑血流量(cerebral blood flow, CBF)等脑血管血流动力学参数是脑血氧水平及脑血管储备功能诊断依据, 现有检测手段存在技术复杂及相应试剂或设备不适用于所有诊断人群等缺点。 为解决以上问题, 利用近红外光谱技术(NIRS)结合吲哚青绿(indocyanine green, ICG)脉搏色素浓度法, 研究了一种无创、 快速、 可重复测量的脑血流量床旁检测方法NIRS-ICG。 该方法根据静脉注射ICG后脑组织及脑动脉血流中三种主要吸光色团氧合血红蛋白(oxygenated hemoglobin, HbO2)、 还原血红蛋白(reduced hemoglobin, HbR)及ICG的浓度变化情况, 建立脑组织及脑动脉血流中ICG积累量及引入量模型, 以获得脑血氧及CBF等脑血流动力学参数。 为验证该方法的可行性, 将NIRS-ICG应用于血碳酸正常及高碳酸血症病理模型的实验猪的脑血流情况检测。 具体方法是: 分别对四组实验猪用按0%, 3%, 6%, 9%比例调制的CO2和空气混合气体施行机械通气, 静脉快速推注ICG后, 利用NIRS-ICG方法测量CBF、 脑动脉血氧饱和度(cerebral arterial oxygen saturation, SaO2)及脑血管管床平均循环时间(mean transit time, MTT)。 实验结果表明, NIRS-ICG测得的CBF随CO2比率升高而升高, SaO2随着CO2比例的升高而降低, MTT并无显著变化, 与生理变化一致。 因此, 该方法可为脑血氧及脑血管储备功能诊断提供可靠依据。

Neonatal stroke is similar to the stroke that occurs in adults and produces a significant morbidity and long-term neurologic and cognitive deficits. There are important differences in the factors, clinical events and outcomes associated with the stroke in infants and adults. However, mechanisms underlying age differences in the stroke development remain largely unknown. Therefore, treatment guidelines for neonatal stroke must extrapolate from the adult data that is often not suitable for children. The new information about differences between neonatal and adult stroke is essential for identification of significant areas for future treatment and effective prevention of neonatal stroke. Here, we studied the development of stress-induced hemorrhagic stroke and possible mechanisms underlying these processes in newborn and adult rats. Using histological methods and magnetic resonance imaging, we found age differences in the type of intracranial hemorrhages. Newborn rats demonstrated small superficial bleedings in the cortex while adult rats had more severe deep bleedings in the cerebellum. Using Doppler optical coherent tomography, we found higher stress-reactivity of the sagittal sinus to deleterious effects of stress in newborn vs. adult rats suggesting that the cerebral veins are more vulnerable to negative stress factors in neonatal vs. adult brain in rats. However, adult but not newborn rats demonstrated the stroke-induced breakdown of blood brain barrier (BBB) permeability. The one of possible mechanisms underlying the higher resistance to stress-related stroke injures of cerebral vessels in newborn rats compared with adult animals is the greater expression of two main tight junction proteins of BBB (occludin and claudin-5) in neonatal vs. mature brain in rats.

Using the laser speckle contrast imaging and wavelet-based analyses, we investigate a latent (a “hidden") stage of the development of intracranial hemorrhages (ICHs) in newborn rats. We apply two measures based on the continuous wavelet-transform of blood flow velocity in the sagittal sinus, namely, the spectral energy in distinct frequency ranges and a multiscality degree characterizing complexity of experimental data. We show that the wavelet-based multifractal formalism reveals changes in the cerebrovascular blood flow at the development of ICH.

Laser speckle contrast imaging (LSCI) is a powerful tool for blood flow mapping. In this paper, we described a simple algorithm based on histogram analysis of laser speckle contrast image to provide rapid differentiation between macro- and microcirculations. The algorithm was successfully verified by the study of blood flow in rat cortex under functional activation.

Hypoxia is closely related to many diseases and often leads to death. Early detection and identification of the hypoxia causes may help to promptly determine the right rescue plan and reduce the mortality. We proposed a new multiparametric monitoring method employing mitochondrial reduced nicotinamide adenine dinucleotide (NADH) fluorescence, regional reflectance, regional cerebral blood flow (CBF), electrocardiography (ECG), and respiration under six kinds of acute hypoxia in four categories to investigate a correlation between the parameter variances and the hypoxia causes. The variation patterns of the parameters were discussed, and the combination of NADH and CBF may contribute to the identification of the causes of hypoxia.

A novel hemodynamic model has been recently introduced, which provides analytical relationships between the changes in cerebral blood volume (CBV), cerebral blood flow (CBF), and cerebral metabolic rate of oxygen (CMRO₂), and associated changes in the tissue concentrations of oxy- and deoxy-hemoglobin (△O and △D) measured with near-infrared spectroscopy (NIRS) [S. Fantini, Neuroimage 85, 202–221 (2014)]. This novel model can be applied to measurements of the amplitude and phase of induced hemodynamic oscillations as a function of the frequency of oscillation, realizing the novel technique of coherent hemodynamics spectroscopy (CHS) [S. Fantini, Neuroimage 85, 202–221 (2014); M. L. Pierro et al., Neuroimage 85, 222–233 (2014)]. In a previous work, we have demonstrated an in vivo application of CHS on human subjects during paced breathing [M. L. Pierro et al., Neuroimage 85, 222–233 (2014)]. In this work, we present a new analysis of the collected data during paced breathing based on a slightly revised formulation of the hemodynamic model and an efficient fitting procedure. While we have initially treated all 12 model parameters as independent, we have found that, in this new implementation of CHS, the number of independent parameters is eight. In this article, we identify the eight independent model parameters and we show that our previous results are consistent with the new formulation, once the individual parameters of the earlier analysis are combined into the new set of independent parameters.

目的: 应用CT灌注成像技术观察帕金森病合并抑郁患者局灶脑血流灌注的特点, 进一步探讨抑郁症发生与脑血流的关系。方法: 将41例帕金森患者根据是否合并抑郁症分为帕金森病组22例、帕金森病合并抑郁症者为抑郁组19例、其中抑郁组分为经颅磁刺激(rTMS)治疗前组、治疗后组, 3组均进行CT局部脑血流灌注显像, 半定量分析各脑区血流灌注情况。结果: 帕金森合并抑郁症组患者双侧额叶、颞叶和基底节的脑血流量测定(CBF)较帕金森病组显著下降(P<0.05); 抑郁组左、右侧脑血流低灌注存在不对称性, 左侧额叶、顶叶的CBF较右侧显著下降(P<0.01); rTMS治疗后脑血流灌注较治疗前改善, HAMD评分改善(P<0.05)。结论: 帕金森患者存在局灶性脑血流灌注降低, 合并抑郁症患者额、顶叶下降更明显, 经颅磁刺激治疗后脑血流低灌注改善。