脑高级功能的功能磁共振成像研究

大脑是生物体内结构和功能最复杂的组织 ,大脑的神经细胞总数约为 1 0 1 2 个 ,相当于整个银河系星体的总数。此外 ,它还有比神经细胞多 1 0～ 50倍的神经胶质细胞 ,这些神经胶质细胞也可能在处理信息中起作用。另外 ,大脑是人体接受外界信号、产生感觉、形成意识、进行逻辑思维、发出指令、产生行为的指挥部 ;是人体内外环境信息获得、存储、处理、加工和整合的中枢。对脑高级功能的研究有助于我们认识脑、保护脑、乃至创造脑[1 ] 。脑高级功能包括语言、记忆、感知觉、情绪、思维等许多方面。历史上最早是从解剖人的尸体和研究脑局部损伤…     

儿童脑磁共振功能成像的研究进展

随着现代影像学技术的快速发展，功能磁共振成像技术在基础和临床方面的应用日益广泛。在成人脑功能的磁共振成像研究方面已经取得可喜的成绩，有关儿童脑的功能性磁共振成像研究的报道尚较少，但正日益受到关注，就近年来儿童脑磁共振功能成像的研究进展进行综述。     

磁共振脑功能成像研究进展

血液动力学反应与神经活动间存在着密切的联系,磁共振脑功能成像是利用大脑功能区活动时,脑组织的活跃可引起局部顺磁性的脱氧血红蛋白生成减少,使局部脑组织Ｔ２及Ｔ２的弛瞎长,从而获得激活脑区的功能成像图,其突出特点是应用了平面回波（ＥＰＩ）技术,磁共振脑功能成像已用于人脑各种功能活动的研究,通过对颅内占位性病变对邻近重要功能区造成影响的研究,能够进一步指导神经外科医师合理地制定手术计划,对改善手术预后有     

儿童脑磁共振功能成像的研究进展

随着现代影像学技术的快速发展,功能磁共振成像技术在基础和临床方面的应用日益广泛.在成人脑功能的磁共振成像研究方面已经取得可喜的成绩,有关儿童脑的功能性磁共振成像研究的报道尚较少,但正日益受到关注.就近年来儿童脑磁共振功能成像的研究进展进行综述.     

磁共振波谱与脑功能成像

随着磁共振波谱技术及功能性磁共振技术的日臻完善和发展,人们对脑,这个人体内最复杂和最重要的器官的认识,从单纯的影像学研究转而进入了分子水平和超细胞(行为)等各个不同层次上的深入探索。这些对于从本质上揭示脑的结构、功能及行为机制之间的关系无疑提供了巨大的研究前景。本文对磁共振波谱技术的原理及目前在临床和基础科学领域取得的进展作简单回顾,对其在脑功能研究中的地位和价值作出评价。一、磁共振波谱(ｍａｇｎｅｔｉｃｒｅｓｏｎａｎｃｅｓｐｅｃｔｒｏｓｃｏｐｙ,ＭＲＳ)是一种利用核磁共振现象和化学位移作用,进行系列特定…     

嗅觉的脑功能磁共振成像

嗅觉属于人脑高级功能之一,嗅觉信息传导及处理具有复杂的网络联系。脑功能磁共振成像是近年新兴的一门研究脑高级活动的技术。着重介绍脑功能磁共振成像在嗅觉机制、嗅觉功能障碍以及引起嗅觉功能障碍常见病等方面的研究进展。     

嗅觉的脑功能磁共振成像

嗅觉属于人脑高级功能之一,嗅觉信息传导及处理具有复杂的网络联系.脑功能磁共振成像是近年新兴的一门研究脑高级活动的技术.着重介绍脑功能磁共振成像在嗅觉机制、嗅觉功能障碍以及引起嗅觉功能障碍常见病等方面的研究进展.     

脑高级功能磁共振成像研究

大脑是生物体内结构和功能最复杂的组织，大脑的神经细胞总数约为1012个，相当于整个银河系星体的总数。此外，它还有比神经细胞多10-50倍的神经胶质细胞，这些神经胶质细胞也可能在处理信息中起作用。另外，大脑是人体接受外界信号、产生感觉、形成意识、进行逻辑思维、发出指令、产生行为的指挥部，是人体内外环境信息获得、存     

人类听觉的脑功能磁共振成像研究

脑功能磁共振成像(fMRI)已广泛应用于人体运动、感觉、视觉、味觉、语言及各种复杂认知任务的研究,近年来有关听觉的fMRI研究报道也日益增多,并显示出其潜在和广阔的临床应用前景.     

癫痫磁共振脑功能成像研究进展

癫痫是神经科仅次于脑血管病的第二高发疾病．其中约70％的病例可用药物治愈或控制．其余为难治性癫痫。手术治疗是控制顽固性癫痫的重要手段。目前,手术能使80％的患者癫痫发作得到有效控制,其治疗效果有赖于癫痫灶和脑功能区的准确定位。近年来磁共振功能成像(functional magnetic resonance imaging．fMRI)技术飞速发展,对癫痫患者认知功能及手术治疗评价能发挥重要作用。     

Functional MR Imaging of Psychogenic Amnesia: A Case Report

We present here a case in which functional MR imaging (fMRI) was done for a patient who developed retrograde psychogenic amnesia for a four year period of her life history after a severe stressful event. We performed the fMRI study for a face recognition task using stimulation with three kinds of face photographs: recognizable familiar faces, unrecognizable friends'' faces due to the psychogenic amnesia, and unfamiliar control faces. Different activation patterns between the recognizable faces and unrecognizable faces were found in the limbic area, and especially in the amygdala and hippocampus.     

颅内血管外皮细胞瘤的磁共振影像研究

目的　分析颅内血管外皮细胞瘤的磁共振影像表现。方法　选取经手术病理证实的颅内血管外皮细胞瘤 2 7例 ,男 1 6例 ,女 1 1例 ,所有病例均进行了MR检查 ,回顾分析其MR影像表现。结果　颅内血管外皮细胞瘤在MR影像表现上有如下特点 :(1 )肿瘤主要表现为等长T1 、等长T2 混杂信号影 ,偶可见短T1 或短T2 信号影 ,注药后 ,肿瘤增强明显但不均匀 ;(2 )外形呈不规则分叶状 ;(3)半数以上的肿瘤与硬膜窄基底相连 ;(4)肿瘤内常可见血管流空影而见不到钙化影 ;(5)肿瘤附近骨质可见破坏而见不到增生硬化。结论　颅内血管外皮细胞瘤有比较典型的MR影像特点 ,结合临床表现有助于其术前正确诊断     

T2 FLAIR增强扫描在颅内病变中价值的初步研究

目的探讨增强T2FLAIR在颅内病变诊断中的价值。方法58例资料完整并在增强T1WI或增强FLAIR上有强化的患者,确定增强T1WI和增强FLAIR上病变有无强化、强化的显著性、肿瘤性病变强化区的边界。结果3例脑梗塞在增强T1WI上未见强化,3例脑肿瘤在增强FLAIR上未见强化,1例脑膜瘤在增强FLAIR上呈负性强化;余51例中11例在增强FLAIR上强化更显著,16例在2个序列上强化相似,24例在T1WI上强化更显著。4例结核的脑膜病变范围和1例静脉窦血栓者回流受阻的皮层静脉在增强FLAIR上显示更加明确。结论增强T2FLAIR在颅内病变的诊断中有一定的价值,当增强T1WI显示不满意、怀疑脑膜或皮层血管病变时,应行增强T2FLAIR。     

颅内磁共振成像(MRI)环形强化病变

目的　对照研究颅内常见MRI环形强化病变的MR影像表现 ,分析常见病变的影像学特点。方法　回顾性分析了 65例颅内常见MRI环形强化病变的临床及MR影像资料。其中胶质母细胞瘤 17例 ,转移瘤 17例 ,脑脓肿 12例 ,听神经鞘瘤 8例 ,颅咽管瘤 7例 ,脑囊虫 3例 ,原发性恶性淋巴瘤 1例。全部病例均经手术、病理证实。结果　肿瘤性病变的环形强化表现为厚壁 ,且壁厚薄不均、形态不规整 ,其中高度恶性肿瘤的强化环明显厚薄不均一 ,尤其是内壁凹凸不平、毛糙不光滑。非肿瘤性病变的强化环通常表现为形态规整 ,厚薄较为均匀一致 ,内壁光滑。结论　颅内常见MRI环形强化病变的不同表现形式可以为诊断提供重要信息 ,同时结合病人的病史、年龄、部位以及MR平扫的影像表现 ,在大多数情况下是可以做出正确诊断的     

Multidisciplinary Functional MR Imaging for Prostate Cancer

Various functional magnetic resonance (MR) imaging techniques are used for evaluating prostate cancer including diffusion-weighted imaging, dynamic contrast-enhanced MR imaging, and MR spectroscopy. These techniques provide unique information that is helpful to differentiate prostate cancer from non-cancerous tissue and have been proven to improve the diagnostic performance of MRI not only for cancer detection, but also for staging, post-treatment monitoring, and guiding prostate biopsies. However, each functional MR imaging technique also has inherent challenges. Therefore, in order to make accurate diagnoses, it is important to comprehensively understand their advantages and limitations, histologic background related with image findings, and their clinical relevance for evaluating prostate cancer. This article will review the basic principles and clinical significance of functional MR imaging for evaluating prostate cancer.     

正常前列腺MR弥散成像的初步应用

目的　探讨MR弥散成像 (DWI)在正常前列腺中的特点及应用价值。方法　随机选择无泌尿系统疾病的健康志愿者 3 0名 (年龄 2 0～ 40岁 ) ,采用SiemensSymphony 1.5T磁共振成像系统 ,在平面回波成像 (EPI)基础上进行MR弥散成像 ,并计算前列腺中央带和外周带的平均表观弥散系数。结果　MR弥散成像能较清晰地显示正常前列腺的中央带和外周带 ,其平均表观弥散系数分别为 :(1.883± 0 .3 7)× 10 -3 mm2 /s ,(2 .2 5 4± 0 .77)× 10 -3 mm2 /s ;大b值、大b值差所测得的ADC值更精确 ;3种成像方式 (DWI、T2 WI、T2 WI FS)中对比噪声比 (CNR)无显著性差异 (Ρ >0 .0 5 )。结论　 1.5T磁共振成像系统可以进行正常前列腺的MR弥散成像 ,有望对前列腺疾病的机理研究和临床诊断提供新的帮助。     

Cranial Nerve Clock: Part II: Functional MR Imaging of Brain Activation during a Declarative Memory Task

RATIONALE AND OBJECTIVES: The authors performed this study to assess brain activation during encoding and successful recall with a declarative memory paradigm that has previously been demonstrated to be effective for teaching students about the cranial nerves. MATERIALS AND METHODS: Twenty-four students underwent functional magnetic resonance (MR) imaging during encoding and recall of the name, number, and function of the 12 cranial nerves. The students viewed mnemonic graphic and text slides related to individual nerves, as well as their respective control slides. For the recall paradigm, students were prompted with the numbers 1-12 (test condition) intermixed with the number 14 (control condition). Subjects were tested about their knowledge of cranial nerves outside the MR unit before and after functional MR imaging. RESULTS: Students learned about the cranial nerves while undergoing functional MR imaging (mean post- vs preparadigm score, 8.1 +/- 3.4 [of a possible 12] vs 0.75 +/- 0.94, bilateral prefrontal cortex, left greater than right; P < 2.0 x 10(-12)) and maintained this knowledge at I week. The encoding and recall paradigms elicited distributed networks of brain activation. Encoding revealed statistically significant activation in the bilateral prefrontal cortex, left greater than right [corrected]; bilateral occipital and parietal associative cortices, parahippocampus region, fusiform gyri, and cerebellum. Successful recall activated the left much more than the right prefrontal, parietal associative, and anterior cingulate cortices; bilateral precuneus and cerebellum; and right more than the left posterior cingulate. CONCLUSION: A predictable pattern of brain activation at functional MR imaging accompanies the encoding and successful recall of the cranial nerves with this declarative memory paradigm.     

肺鳞、腺癌磁共振成像的初步研究

目的探讨肺鳞、腺癌的MRI信号及形态学表现。材料和方法经病理证实的肺鳞、腺癌16例，MRI可见肿块14例，其中鳞癌8例，腺癌6例，比较二者之间的MRI信号及形态学改变。结果肺鳞癌MRIT2WI多为坏死为主的不均匀稍高信号(4／8)，肺腺癌MRIT2WI多为纤维分隔为主的不均匀稍高信号(4／6)，二者之间信号改变有统计学差异。T1WI二者之间无差异。肺鳞癌肿块>5cm，分叶征及阻塞性改变比肺腺癌发生率高。结论肺鳞、腺癌的MRI信号及形态学改变有一定鉴别价值。     

Functional Neuroanatomy in Depressed Patients with Sexual Dysfunction: Blood Oxygenation Level Dependent Functional MR Imaging

Objective

To demonstrate the functional neuroanatomy associated with sexual arousal visually evoked in depressed males who have underlying sexual dysfunction using Blood Oxygenation Level Dependent-based fMRI.

Materials and Methods

Ten healthy volunteers (age range 21-55: mean 32.5 years), and 10 depressed subjects (age range 23-51: mean 34.4 years, mean Beck Depression Inventory score of 39.6±5.9, mean Hamilton Rating Scale Depression (HAMD)-17 score of 33.5±6.0) with sexual arousal dysfunction viewed erotic and neutral video films during functional magnetic resonance imaging (fMRI) with 1.5 T MR scanner (GE Signa Horizon). The fMRI data were obtained from 7 oblique planes using gradient-echo EPI (flip angle/TR/TE=90°/6000 ms/50 ms). The visual stimulation paradigm began with 60 sec of black screen, 150 sec of neutral stimulation with a documentary video film, 30 sec of black screen, 150 sec of sexual stimulation with an erotic video film followed by 30 sec of black screen. The brain activation maps and their quantification were analyzed by SPM99 program.

Results

There was a significant difference of brain activation between two groups during visual sexual stimulation. In depressed subjects, the level of activation during the visually evoked sexual arousal was significantly less than that of healthy volunteers, especially in the cerebrocortical areas of the hypothalamus, thalamus, caudate nucleus, and inferior and superior temporal gyri. On the other hand, the cerebral activation patterns during the neutral condition in both groups showed no significant differences (p < 0.01).

Conclusion

This study is the first demonstration of the functional neuroanatomy of the brain associated with sexual dysfunction in depressed patients using fMRI. In order to validate our physiological neuroscience results, further studies that would include patients with other disorders and sexual dysfunction, and depressed patients without sexual dysfunction and their treatment response are needed.