时间聚类分析功能MRI对癫痫病灶定位的初步研究

目的 探讨癫痫病灶的定位方法 .方法 对12例颅内有明确局灶性病变的癫痫患者行静息状态下的功能MR成像(fMRI).采用时间聚类分析(TCA)软件程序实现TCA算法,并对fMRI数据进行分析,经统计分析后得到脑解剖-功能融合图像,观察病变区有无激活反应,并对TCA反应聚类时间曲线与统计参数图(SPM)头部运动曲线进行比较.结果 观察脑解剖-功能融合图像发现,12例中8例在病变区有激活反应,4例未发现明显病灶区激活反应.病灶区无论有无激活反应,反应幅度较大的TCA反应聚类时间点和头部运动曲线之间有一定的对应关系.结论 TCA作为一种探索性数据驱动方法 ,一定程度上可以对癫痫的发作问期痫样放电活动进行检测和定位,但其结果 会受到头部运动的影响,分析时需考虑到生理、病理及运动等多种因素.     

Clinical applications of functional MRI at 1.0 T: motor and language studies in healthy subjects and patients

In this article we describe clinical applications of functional MRI (fMRI) at 1.0 T. All experiments were performed on a commercially available 1.0-T system (Magnetom Impact Expert, Siemens AG, Erlangen, Germany) using a blood oxygen level-dependent (BOLD)-sensitive multi-slice EPI technique (TE 66 ms, 4 mm slice thickness, 210 mm field of view, 64 × 64 acquisition matrix). Different paradigms for localization of the motor cortex and for language lateralization were tested in healthy subjects and patients. Methodological considerations concerning the development of the paradigms are also described. In all healthy subjects, motor activation elicited BOLD signal changes in the sensorimotor cortex, permitting identification of primary motor and sensory cortical areas. Furthermore, focal activation of different cortical areas by a language task was possible in 6 of 10 subjects. Nineteen motor studies were performed in 18 patients with supratentorial lesions, in most cases prior to neurosurgical procedures. In 14 studies, fMRI results demonstrated the localization of the motor hand areas relative to the lesion. The results proved valuable for preoperative planning and contributed to therapeutical decisions. We conclude that functional MRI for clinically relevant applications, such as localization of motor and language function, is feasible even at a field strength of 1.0 T without dedicated equipment. Received: 5 May 1998; Revision received: 1 July 1998; Accepted: 13 July 1998     

Cortical mapping by functional magnetic resonance imaging in patients with brain tumors

The aim of our study was to establish the effectiveness of the functional MRI (fMRI) technique in comparison with intraoperative cortical stimulation (ICS) in planning cortex-saving neurosurgical interventions. The combination of sensory and motor stimulation during fMRI experiments was used to improve the exactness of central sulcus localization. The study subjects were 30 volunteers and 33 patients with brain tumors in the rolandic area. Detailed topographical relations of activated areas in fMRI and intraoperative techniques were compared. The agreement in the location defined by the two methods for motor centers was found to be 84%; for sensory centers it was 83%. When both kinds of activation are taken into account this agreement increases to 98%. A significant relation was found between fMRI and ICS for the agreement of the distance both for motor and sensory centers (p=0.0021–0.0024). Also a strong dependence was found between the agreement of the location and the agreement of the distance for both kinds of stimulation. The spatial correlation between fMRI and ICS methods for the sensorimotor cortex is very high. fMRI combining functional and structural information is very helpful for preoperative neurosurgical planning. The sensitivity of the fMRI technique in brain mapping increases when using both motor and sensory paradigms in the same patient.     

Recovery from mild head injury in sports: evidence from serial functional magnetic resonance imaging studies in male athletes.

OBJECTIVE: To examine functional brain activation patterns before and after postconcussive symptoms (PCS) resolution. DESIGN: Prospective serial study with male athletes using functional magnetic resonance imaging (fMRI). SETTING: Hospital laboratory and imaging facility. PARTICIPANTS: 9 symptomatic concussed athletes who experienced persisting PCS at least 1 month postinjury and 6 healthy athletes. INTERVENTIONS: All athletes filled out a PCS checklist and underwent an fMRI session during which they performed a working-memory task. MAIN OUTCOME MEASUREMENTS: Behavioral outcomes were response speed and accuracy on the working memory tasks performed during the fMRI session. Functional imaging outcomes were blood oxygen level-dependent fMRI activation patterns associated with a working memory task. RESULTS:: There was no difference in behavioral performance between the groups. Despite normal structural MRI findings, all symptomatic concussed athletes initially showed atypical brain activation patterns in the dorsolateral prefrontal cortex (DLPC). Compared to the initial postinjury evaluation, those athletes at follow-up with PCS resolved showed significant increases in activation in the left DLPC. Concussed athletes whose PCS status remained unchanged at follow-up continued to show atypical activation in DLPC. Healthy athletes showed remarkably clear and consistent brain activations in DLPC initially as well as in follow-up, highlighting the test-retest reliability of fMRI. CONCLUSIONS: The results demonstrate the feasibility of using fMRI to detect an underlying pathology in symptomatic concussed athletes with normal structural imaging results and its potential to document recovery. Such information may be of considerable value for clinical judgment and patient management.     

三维时间飞跃对三叉神经痛的诊断价值

目的 探讨三叉神经痛神经患者的ＭＲ表现为其诊断价值。方法 应用三维时间飞跃（３Ｄ－ＴＯＦ）序列,结合ＳＥ及快速液体衰减反转恢复（ＦＬＡＩＲ）序列,回顾性分析了１０４例三叉神经痛患者ＭＲ表现及手术结果。结果 （１）１０４例三叉神经痛患者中ＭＲＩ诊断为血管压迫或接触的为７５例,术中证实有血管压迫或接触的为６９例;桥小脑角肿瘤共１４例,ＭＲＩ确诊１３例,另１例由手术确诊;血管性病变的为５例,均由微血管减     

Motor functional MRI for pre-operative and intraoperative neurosurgical guidance

Functional MRI (fMRI) may provide a means of locating areas of eloquent cortex that can be used to guide neurosurgeons in their quest to maximize intracerebral tumour resection whilst minimizing post-procedural neurological deficits. This work aimed to develop and provide an initial assessment of such a technique. 19 patients with mass lesions close to the primary motor cortex underwent fMRI at 1.5T. A single shot echo planar technique was used to acquire data corresponding to right and left hand movement. Resultant activation maps were used to aid pre-surgical planning. Data was used in conjunction with an intraoperative navigation system in 13 cases. Activation was attributed to primary motor, primary somatosensory or supplementary motor cortex in 17 of 19 subjects. No permanent changes in motor deficit were detected post surgery. The additional information provided by fMRI, particularly when incorporated into a neuronavigation guided craniotomy, was deemed highly valuable to the neurosurgeon as it enabled safe resection of tumour in anatomical locations previously deemed to be too high risk for safe resection using conventional (non-fMRI-guided) technique. This observation is reinforced by the fact that no patients suffered permanent neurological deficit after radical tumour debulking (surgical estimates >90% tumour resection).     

3D-TOF磁共振血管成像诊断血管压迫性三叉神经痛的价值

目的　探讨增强薄层三维体积扫描时间飞跃法磁共振血管成像 ( 3D -TOFMRA)诊断血管压迫性三叉神经痛的价值。方法　回顾性分析 37例临床拟诊为血管压迫性三叉神经痛患者的常规颅脑MRI及增强薄层 3D -TOF磁共振血管成像资料。结果　增强薄层 3D -TOFMRA发现 37例中 2 4例共 2 7侧三叉神经存在血管压迫或接触 ,其中症状侧三叉神经有血管压迫或接触 2 4例 ,无症状侧三叉神经有血管压迫或接触 3例 ,本组病例统计学分析表明 ,三叉神经痛患者症状的出现与三叉神经存在血管压迫或接触有显著相关关系 (Ρ <0 .0 0 5 )。 13例为非血管压迫性三叉神经痛。压迫三叉神经的血管为小脑上动脉 (SCA) 14例 ,小脑前下动脉(AICA) 5例 ,起源不清的血管 3例 ,扭曲的椎动脉 1例 ,血管畸形 1例。结论　增强薄层 3D -TOFMRA可清楚显示三叉神经脑池段与毗邻血管的关系 ,明显优于常规颅脑MRI,是目前检测血管压迫性三叉神经痛最佳的影像学检查方法 ,对明确诊断和指导治疗三叉神经痛具有重大意义。     

Role of enhanced MRI in the follow-up of patients with medically refractory trigeminal neuralgia undergoing stereotactic radiosurgery using the gamma knife: initial experience

PURPOSE: The purpose of this work was to evaluate the early posttreatment MR findings, and their clinical utility, in patients with trigeminal neuralgia undergoing stereotactic radiosurgery using the gamma knife. METHOD: Twenty-six patients with medically refractory trigeminal neuralgia underwent stereotactic radiosurgery. A single dose of 70-90 Gy was administered to the proximal root entry zone (n = 21) or the retrogasserian portion (n = 5) of the trigeminal nerve. Posttreatment enhanced MRI and clinical assessment were performed at 3-6 months. RESULTS: Five patients did not have radiologic follow-up. There were no changes identified in the treated trigeminal nerve or adjacent brainstem in 19 of 21 patients. Two patients with multiple sclerosis developed abnormal signal and enhancement in the brainstem and/or trigeminal nerve; neither had clinical complications. Onset of therapeutic effect ranged from 3 weeks to 3 months; 19 patients had a beneficial response. CONCLUSION: Results of enhanced MRI 3-6 months after stereotactic radiosurgical treatment of trigeminal neuralgia do not correlate with the clinical response. Because beneficial clinical responses or treatment failures are apparent by 3 months, routine posttreatment MRI in these patients is not warranted.     

肝硬化患者工作记忆任务的fMRI研究

目的：通过n-back语义工作记忆任务的功能磁共振成像（~MRI）技术探讨肝硬化患者语义工作记忆损伤的神经病理学机制。方法：对10例轻微肝性脑病（MHE组）、14例单纯肝硬化（non-HE组）患者及16例正常对照者（对照组）行n-back语义工作记忆任务的fMRI研究。n-back实验采用组块设计,对照状态为0-back,任务状态为1-back和2-back。采用基于MATLAB的SPM8软件对数据进行处理分析。采用单样本t检验分析三组受试者在两种任务状态下的大脑激活情况,采用单因素方差分析观察三组受试者两种任务状态（1和2-back）下脑区激活的差异,采用Pearson相关分析行工作记忆任务脑激活区与任务执行正确率及反应时间之间的相关性。结果：在n-back任务中,三组受试者均表现为额顶叶脑网络的激活,包括双侧前额叶、双侧顶叶、双侧前运动区以及辅助运动区。在1-back任务下,non-HE组及MHE组主要表现为工作记忆部分脑区激活的增加;在2-back任务下,non-HE组及MHE组表现为工作记忆相关脑区激活的减低。肝硬化患者左侧额中回激活与2-back任务执行正确率密切相关。结论：肝硬化患者存在语义工作记忆相关脑区的损害。1-back任务时主要表现为脑区的代偿,但MHE较单纯肝硬化代偿能力减低;2-back任务难度超出代偿限度,主要表现为激活下降,且MHE较单纯肝硬化损伤更明显。     

低场强磁共振CBASS序列在三叉神经痛病因诊断中的应用价值

目的:探讨低场强MRI CBASS序列在三叉神经痛(TN)病因中的研究价值。方法:对50例TN患者依次采用CBASS序列,结合FE序列,FE3D-TOF序列进行检查,对CBASS序列成像MRI表现及手术结果作回顾性分析。结果:①50例TN患者中,肿瘤性病变7例,其它3例,排除上述继发性TN10例;40例原发性TN患者入选,疼痛侧MRICBASS序列发现有三叉神经血管压迫或接触29例(29/40),非疼痛侧有三叉神经血管接触9例(9/40),两组相比有显著性差异2=20.050,(P<0.0001);②50例患者均行手术治疗,CBASS序列对原发性TN诊断的敏感性为93.1%,特异性为81.8%,准确性90.01%,假阴性为18.21%,假阳性为6.9%。结论:三叉神经脑池段血管压迫或接触是TN的首要原因,CBASS序列成像能清晰显示三叉神经与邻近血管、肿瘤病变或其他病变之间的关系,对临床诊治具有重要指导意义。     

健康成人及脑肿瘤患者利手和非利手简单与复杂运动fMRI研究

目的:应用脑血氧水平依赖性功能MRI(BOLD-f MRI)研究健康成年人及脑肿瘤患者运动功能皮层定位并探讨其对脑肿瘤的临床应用价值。方法:10例健康志愿者和32例脑肿瘤患者(术前25例,术后7例)共42例受试者,行利手、非利手的单手握拳(简单运动)或单手对指(复杂运动)运动的脑BOLD-f MRI检查,分析脑肿瘤对运动皮层位置和功能的影响。结果:健康成人运动皮层主要位于对侧躯体感觉运动皮层(SMC),单或双侧辅助运动区(SMA)、运动前区(PMA)和双侧小脑半球。复杂运动或非利手运动时脑功能激活区范围和程度较简单运动或利手运动时增多。累及功能皮层的脑肿瘤患者,可见患侧部分脑功能区激活,但激活区移位、分布弥散。术后脑肿瘤患者功能皮层的位置基本恢复正常。结论:BOLD-f MRI是一种有效而无创的脑功能皮层定位方法,有利于脑肿瘤的精确定位诊断并指导临床治疗。     

EEG-triggered functional MRI in patients with pharmacoresistant epilepsy

Functional magnetic resonance imaging (fMRI) triggered by scalp electroencephalography (EEG) recordings has become a promising new tool for noninvasive epileptic focus localization. Studies to date have shown that it can be used safely and that highly localized information can be obtained. So far, no reports using comprehensive clinical information and/or long-term follow-up after epilepsy surgery in a larger patient group have been given that would allow a valuable judgment of the utility of this technique. Here, the results of 11 patients with EEG-triggered fMRI exams who also underwent presurgical evaluation of their epilepsy are given. In most patients we were able to record good quality EEG inside the magnet, allowing us to trigger fMRI acquisition by interictal discharges. The fMRI consisted of echoplanar multislice acquisition permitting a large anatomical coverage of the patient's brain. In 8 of the 11 patients the exam confirmed clinical diagnosis, either by the presence (n = 7) or absence (n = 1) of focal signal enhancement. In six patients, intracranial recordings were carried out, and in five of them, the epileptogenic zone as determined by fMRI was confirmed. Limitations were encountered a) when the focus was too close to air cavities; b) if an active epileptogenic focus was absent; and c) if only reduced cooperation with respect to body movements was provided by the patient. We conclude that EEG-triggered fMRI is a safe and powerful noninvasive tool that improves the diagnostic value of MRI by localizing the epileptic focus precisely.     

Functional MRI in symptomatic proliferative angiopathies

Seizures, the main expression of cerebral arteriovenous malformations (AVMs) can be difficult to control medically. We studied fMRI in correlation with clinical findings cerebral activation clusters patterns in relation with singular AVMs (proliferative angiopathy). We carried out blood oxygen-level dependent functional MRI (fMRI) in seven patients with language problems due to capillary ectasia with verbal fluency and repetition language tasks in box-car paradigms. fMRI maps were calculated with cross-correlation coefficients and superimposed on brain anatomy. Five patients had perimalformative and/or contralateral areas of ipsi- and contralateral activation clusters redistribution. One patient who underwent fMRI after a severe focal post-ictal deficit had total hemisphere contralateral activation clusters redistribution.     

Central trigeminal involvement in multiple sclerosis using high-resolution MRI at 3 T

Trigeminal neuralgia and sensory disturbance is common in multiple sclerosis (MS). Recent literature suggests that signal abnormalities in the cisternal trigeminal nerve and pontine root entry zone are seen in approximately 3% of MS patients, using conventional diagnostic MRI. The objective of this study was to determine the prevalence of trigeminal lesions using high-resolution MRI at 3T. Forty-seven patients with clinically definite MS, chosen at random from the outpatient population of a neuroscience centre underwent MRI on a Siemens 3T Trio machine. Three 3D sequences of T2 TSE (turbo spin echo), T2 FLAIR (fluid attenuated inversion recovery) and T1 IR (inversion recovery) were acquired in the coronal plane. The sequences were of contiguous 1 mm slices with in-plane resolution of up to 0.5 mm by 0.5 mm. Images were read by both a neurologist and a neuroradiologist. Any clinical history of trigeminal symptoms was determined for all subjects. The results showed that 11 patients (23%) had high signal in the trigeminal root entry zone and either the trans-cisternal nerve or pontine nucleus; example images are given. MRI changes did not correspond to clinical symptoms (chi square probability 1.000). The study concludes that high-resolution MRI at 3T yielded a high prevalence of detectable trigeminal abnormality in the MS sample studied. MRI involvement did not correspond to trigeminal symptoms.Both facial pain (including trigeminal neuralgia) and non-painful facial sensory disturbance are routinely encountered in patients with multiple sclerosis (MS). Previous studies suggest that the prevalence of trigeminal lesions is between 3% and 7% [1, 2], and such lesions may or may not be related to clinical symptoms [1–5]. The relationship between trigeminal sensory symptoms and trigeminal lesions remains unclear. The use of thin, contiguous slices and higher field strength, which improves signal to noise ratio (SNR), may yield greater detection of abnormalities [6–8]. A prospective study was therefore undertaken to determine the prevalence of central trigeminal lesions in MS, using high-resolution MRI at 3 T, and the relation between the presence of lesions and facial sensory symptoms.     

3D-TSE序列在三叉神经痛病因诊断中的价值

目的　探讨MRI三维快速自旋回波 (3D TSE)序列在三叉神经痛 (TN)病因研究中的价值。资料与方法　应用 3D TSE序列 ,结合常规MRI序列 ,分析 5 0例TN患者和 5 0名正常对照者的MRI表现及手术结果。结果　 (1) 5 0名正常对照者 10 0侧脑池段三叉神经MRI检查中 ,11侧存在三叉神经血管接触。 5 0名TN患者疼痛侧有血管压迫或接触的为 32例 ,非疼痛侧 5 0侧三叉神经中 ,有血管接触的为 7例 ,经统计学分析 ,TN患者疼痛有无与是否存在血管压迫或接触有统计学意义 (P <0 .0 0 5 )。 (2 ) 5 0例TN患者疼痛侧 ,MRI诊断TN病因中血管压迫或接触占 6 4 % (32 / 5 0 ) ;肿瘤性病变占 16 % (8/ 5 0 ) ;其他占 2 0 % (10 / 5 0 )。 (3)根据手术结果 ,3D TSE序列对TN诊断的敏感性为 10 0 % ,特异性为 80 %。结论　三叉神经脑池段的血管压迫或接触是TN的主要病因 ,3D TSE成像能清晰显示三叉神经与邻近血管、肿瘤性病变或其他病变之间的关系 ,为临床确定治疗方案有重要的指导意义     

三叉神经痛MRI序列研究及诊断价值

目的 探讨MR序列对导致三叉神经痛病变的显示能力及诊断价值.方法 回顾性分析60例三叉神经痛患者临床及MRI资料,与临床手术对照,比较不同序列MRI显示病变能力.所有患者均行常规头部MR平扫,其中9例行增强扫描,49例行桥小脑角区高分辨3D-TOF和3D-快速SE(TSE)序列扫描.利用x2检验分析3D-TOF和3D-TSE两序列的敏感度、特异度和准确度.结果 MR常规平扫及增强扫描显示6例桥小脑区肿瘤、3例三叉神经根及其周围脑膜炎,以及脑干多发硬化斑块及梗死各1例.49例为神经血管压迫所致,与手术对照3D-TOF和3D-TSE序列显示血管压迫的敏感度、特异度、准确度分别为95.3％ (41/43)、66.7％ (4/6)、91.8％ (45/49)和95.6％ (43/45)、50.0％ (2/4)、91.8％ (45/49),两者差异无统计学意义(x2值分别为0.13、0.19、0.17,P值均＞0.5).结论MRI对显示和诊断三叉神经痛病因具有重要意义.MR全脑常规扫描可以显示或排除肿瘤、炎症等病变.桥小脑角区3D-TOF和3D-TSE扫描可以敏感和准确地显示和明确神经、血管的关系.     

Real time fMRI: a tool for the routine presurgical localisation of the motor cortex

In patients with brain lesions adjacent to the central area, exact preoperative knowledge of the spatial relation of the tumour to the motor cortex is of major importance. Many studies have shown that functional magnetic resonance imaging (fMRI) is a reliable tool to identify the motor cortex. However, fMRI data acquisition and data processing are time-consuming procedures, and this prevents general routine clinical application. We report a new application of real time fMRI that allows immediate access to fMRI results by automatic on-line data processing. Prior to surgery we examined ten patients with a brain tumour adjacent to the central area. Three measurements were performed at a 1.5-T Magnetom Vision Scanner (Siemens, Forchheim, Germany) on seven patients and at a 1.5-T Intera Scanner (Philips, Best, The Netherlands) on three patients using a sequential finger-tapping paradigm for motor cortex activation versus at rest condition. Blood oxygen level-dependant (BOLD) images were acquired using a multislice EPI sequence (16 slices, TE 60, TR 6000, FOV 210×210, matrix 64×64). The central sulcus of the left hemisphere could be clearly identified by a maximum of cortical activity after finger tapping of the right hand in all investigated patients. In eight of ten patients the right central sulcus was localised by a signal maximum, whereas in two patients the central sulcus could not be identified due to a hemiparesis in one and strong motion artefacts in the second patient. Finger tapping with one side versus rest condition seems to result in more motion artefacts, while finger tapping of the right versus the left hand yielded the strongest signal in the central area. Real time fMRI is a quick and reliable method to identify the central sulcus and has the potential to become a clinical tool to assess patients non-invasively before neurosurgical treatment.     

Developmental venous anomalies of the posterior fossa with transpontine drainage: report of 3 cases

Developmental venous anomalies (DVA) are considered as variant patterns of cerebral venous drainage. Although generally not rare in the cerebellum, DVA of the brain stem or of the cerebellum with drainage through the brain stem are exceptional findings. Because it is not clear whether DVA may sometimes be of clinical significance, we try to correlate the clinical findings of the patients with the course of the variant vessels. We reviewed the literature and report three additional cases. All patients were examined by MRI and digital subtraction angiography. In particular, we discuss the drainage route as compared with the established patterns of posterior fossa blood drainage, which is directed to the dural sinuses, the petrosal vein or the vein of Galen. In one of our patients suffering from trigeminal neuralgia, the close topical relation of the DVA and the trigeminal nucleus and trigeminal nerve entry zone suggests a causal relationship. In a second case the brain stem symptoms were due to haemorrhage of a concomitant cavernoma. It remains unclear if the occurrence of dysarthria and dysaesthesia in the third patient with brain stem DVA was purely coincidental. The only clinical symptom directly attributable to a DVA with transpontine drainage in our series was trigeminal neuralgia. Received 11 April 1996; Revision received 8 August 1996; Accepted 2 October 1996     

累及大脑皮层运动区的颅内病变手术前后磁共振功能成像

目的：作者利用功能性磁共振成像原理,对颅内病变累及运动皮层的病人进行了术前、术后的成像检查。即对患者进行手指运动功能区的皮层定位检查,分辨这些重要的功能皮层区与病变的相邻关系。方法：３１例需进行手术治疗的病人,采用血氧依赖水平（ＢＯＬＤ）原理进行扫描,并经过计算机后处理获得脑功能区的影像表现。结果：所有的病例均能在脑功能成像检查中表现出局部脑功能活动区（相应的手指运动支配功能区）规律的信号－时间变化曲线。以及由于病变造成的皮层功能区的移位和缩小等形态学改变。结论：在常规的ＭＲ成像后进行功能性ＭＲ成像研究,对需实施颅内占位病变、特别是对有累及运动皮层焦行切除术者有十分重要的临床指导意义。     

Clinical applicability of functional MRI

Functional MRI (fMRI) has become the most widely used modality for examining human brain function in basic and clinical neuroscience. As compared to the application of fMRI in basic neuroscience research, clinical fMRI presents unique challenges. A growing body of literature supports the feasibility of clinical fMRI, with the best-studied applications being localization of motor cortex and lateralization of language. While it may be tempting to assume that fMRI will supercede prior approaches, it may turn out that fMRI will be used to complement more difficult or invasive methods rather than replace them entirely. This article focuses on fMRI studies in patients and patient populations. Specific considerations for such applications include pathophysiological effects on functional physiology, brain-behavior correlations in the presence of cognitive or sensorimotor deficits, and test-retest reliability for longitudinal studies.