冲击波造成的脑创伤是目前较常见的致死致残疾病之一,对冲击性脑损伤的检测与分类具有重要意义。基于连续太赫兹波成像系统,对不同程度冲击波致伤的大鼠脑组织进行了连续太赫兹波衰减全反射成像检测,并采用支持向量机(SVM)分类器对不同创伤程度的脑组织太赫兹波成像结果进行分类识别。结果表明,太赫兹波衰减全反射成像技术可以实现对轻度、中度冲击性脑创伤脑部组织的检测。通过SVM分类器对不同创伤程度的脑部组织成像结果进行分类识别,其分类识别准确率可以达到86.36%。太赫兹波成像技术有望实现对不同程度冲击性脑创伤的早期精确检测与诊断。

太赫兹波因其具有独特的优势,在生物医学检测、安全检查、通信和雷达等多种领域具有重要的应用前景,而太赫兹辐射源是太赫兹技术的应用基础,近年来得到了快速发展。基于光学非线性频率变换技术的太赫兹参量辐射源和差频辐射源可以产生调谐范围宽、输出能量高和单色性好的太赫兹波。本文综述了基于受激电磁耦子散射技术的太赫兹参量辐射源以及基于非线性光学差频技术的太赫兹差频辐射源的研究进展,着重叙述了当前太赫兹参量辐射源和差频辐射源在输出频率范围拓展、能量提高和快速调谐等方面的研究进展,以及太赫兹技术在脑创伤检测中的应用研究进展,并分析了光学太赫兹辐射源及其在脑创伤检测应用的关键技术问题以及发展趋势。

采用Feeney's方法制备了鼠脑创伤模型,利用太赫兹波透射式成像系统对鼠脑的组织切片进行成像检测,结果表明:鼠脑创伤区域相比于正常区域具有更低的透过率。采用三维重构技术实现了鼠脑的三维建模,该模型可以清楚地反映鼠脑内部创伤区域的空间分布。基于太赫兹波多深度切片成像的三维重建技术在生物医学精确诊断方面具有巨大的应用潜力。

由于传统方法在脑疾病治疗方面的局限性, 低照度光疗法越来越受到重视。低照度光疗法利用波长在600 nm-1 100 nm的低功率激光或者准单色光以非破坏和非热行为来调制生物过程, 用于促进伤口愈合, 抑制感染、水肿以及减轻疼痛等。近来, 研究者进行了大量低照度光治疗脑损伤疾病方面的实验, 研究对象从细胞、动物模型到人类, 病症从卒中, 急性脑创伤到慢性脑损伤以及神经退行性病变等。研究结果表明, 低照度光疗法有可能应用于脑部损伤疾病的治疗。介绍了低照度光疗法的机理、应用, 并对低照度光疗法的治疗参数, 包括治疗窗口、波长以及剂量等进行了回顾。

为了探讨3D动脉自旋标记 (arterial spin labeling, ASL)技术对急性创伤性脑损伤(traumatic brain injury, TBI)病人的诊断价值, 将43例急性轻度TBI患者和20例健康志愿者进行了常规MRI(magnetic resonance imaging)和3D ASL扫描。结果表明,3D ASL能显示常规MRI所不能显示的脑内血流灌注情况。3D ASL结果发现, 健康志愿者组双侧前、中、后动脉供血区的脑血流量(cerebral brain flow, CBF)值比较均无差异(P值均＞0.05); TBI患者未出现明显低灌注区的脑实质CBF较志愿者脑实质CBF值明显降低(P值＜0.01); TBI患者脑内局部低灌注区较对侧镜面区的CBF值明显减低(P值＜0.01)。3D ASL技术能检测出急性轻度TBI患者脑实质灌注减低情况, 对于临床诊治有重要意义, 值得在临床推崇。

A frequent consequence of traumatic brain injury (TBI) is cognitive impairment, which results in significant disruption of an individual's everyday living. To date, most clinical rehabilitation interventions still rely on behavioral observation, with little or no quantitative information about physiological changes produced at the brain level. Functional brain imaging has been extensively used in the study of cognitive impairments following TBI. However, its applications to rehabilitation have been limited. This is due in part to the expensive or invasive nature of these modalities. The objective of this study is to apply functional near-infrared spectroscopy (fNIR) to the assessment of attention impairments following TBI. fNIR provides a localized measure of prefrontal hemodynamic activation, which is susceptible to TBI, and it does so in a noninvasive, affordable and wearable way, thus partially overcoming the limitations of other modalities. Participants included 5 TBI subjects and 11 healthy controls. Brain activation measurements were collected during a target categorization task. Significant differences were found in the hemodynamic response between healthy and TBI subjects. In particular, the elicited responses exhibited reduced amplitude in the TBI group. Overall, the results provide first evidence of the ability of fNIR to reveal differences between TBI and healthy subjects in an attention task. fNIR is therefore a promising neuroimaging technique in the field of neurorehabilitation. The use of fNIR in neurorehabilitation applications would benefit from its noninvasiveness and cost-effectiveness and the neurophysiological information obtained through the evaluation of the hemodynamic activation could provide invaluable information to guide the choice of intervention.

利用功能近红外光谱技术(fNIRS)监测颅脑创伤(TBI)模型的大鼠脑组织。在大鼠左头部建立急性局灶性脑挫裂伤模型，以功能近红外光谱技术监测并记录颅脑创伤后大鼠脑部组织的优化散射系数，并利用核磁共振影像学、干湿比重法、有创颅内压(ICP)监测技术监测大鼠颅脑创伤后脑水肿和ICP的变化。实验结果显示创伤后脑部组织的优化散射系数、干湿比重法测量的脑水含量(BWC)和创ICP监测仪测量的ICP，三者在颅脑创伤后随时间的变化规律一致，大鼠脑组织的优化散射系数与BWC和ICP均存在正相关，且对颅脑创伤后脑组织的变化更为敏感。这说明优化散射系数是颅脑创伤监测的良好指标参数。