脑小血管病MRI表现对痴呆的预测作用

随着全球老龄化,痴呆发病率快速上升,而且痴呆具有不可逆性、缺乏有效治疗措施,故 探索预测痴呆发生的有效指标成为关键。脑小血管病（cerebral small vessel disease,CSVD）被认为与 痴呆密切相关,其颅脑磁共振成像（magnetic resonance imaging,MRI）可表现为腔隙（lacunes）、新发皮 层下小梗死（recent small subcortical infarcts）、脑白质高信号（white matter hyperintensities,WMH）、扩 大的血管周围间隙（enlarged perivascular spaces,EPVS）及脑微出血（cerebral microbleeds,CMB）等。本文 通过综述CSVD颅脑MRI表现与痴呆相关性的研究进展,发现多发静息性或位于基底节区的腔隙性梗死 （lacunar infarction,LI）或腔隙、重度WMH、多脑叶分布性脑叶微出血（lobar microbleeds,LMB）,均可作 为预测痴呆发生的有效指标。     

衰老相关的脑小血管病诊疗现状和亟待解决的问题

脑小血管病(cerebral small vessel disease,CSVD)是指脑小动脉、分支小动脉、毛细血管和小静脉病变,导致临床表现为多种症状的一种综合征,如情绪异常、排尿异常、步态异常、腔隙性脑梗死、脑出血、认知功能障碍和痴呆、帕金森综合征等。MRI表现为脑白质损伤也称脑白质高信号(T2WI和FLAIR)、腔隙性梗死、扩大的血管周围间隙、脑微出血及脑萎缩。     

脑小血管病的结构影像学研究

正脑小血管病主要是各种病因累及脑小动脉、微动脉、毛细血管和小静脉,从而引起急性脑卒中、认知障碍、精神行为异常及步态障碍等一系列临床症状的疾病。磁共振上主要表现包括近期皮质下小梗死、腔隙性脑梗死、脑白质高信号、血管周围间隙扩大、脑微出血及脑萎缩。本文对脑小血管病在影像学方面的研究进展进行综述。一、脑小血管病脑小血管病(cerebral small vessel disease,CSVD)由脑血管损伤的各种原因引起的脑血管疾病导致一系列疾病的临床、影像成像和病理变化,包括脑动脉、小动脉、毛细血管     

编者按

正脑小血管病(cerebral small vessel disease,CSVD)中80%左右与老年相关,为衰老性疾病,其中腔隙性脑梗死分别占卒中的25%～30%、老年性痴呆的45%。危险因素主要为高血压、糖尿病、吸烟、睡眠呼吸暂停综合征、慢性肾脏病、皮层下卒中相关的分支动脉粥样硬化性疾病、高脂血症等。其MRI表现主要为:腔隙性脑梗死、脑白质高信号、脑微出血、扩大的血管周围间隙及脑萎缩。诊断结合病史、临床表现和MRI。治疗主要控制危险因素,对腔隙性脑梗死建议长期使用一种抗血小板     

血管周围间隙在脑小血管病中的研究进展

血管周围间隙（perivascular spaces，PVS）是脑小血管周围充满液体的潜在腔隙。扩大的血 管周围间隙（enlarged perivascular spaces，ePVS）已成为脑小血管病（cerebral small vessel diseases，CSVD） 公认的影像标志物之一。PVS的量化依赖于MRI，难点在于ePVS与腔隙灶的鉴别。PVS被证明与年龄、 高血压、其他CSVD影像学标志物、认知功能损害、全身性炎症相关，但仍缺乏较为长期的、针对不同 人群的队列研究。研究ePVS与CSVD病程的关系，有助于临床上对CSVD的早期发现和风险预测。     

貌似半球病变脑桥腔隙性梗死13例临床分析

随着MRI影象技术的普及，脑桥腔隙性梗死并非表现出经典脑桥定位体征，而表现对侧偏身运动障碍（面、舌瘫）和（或）偏身感觉障碍、共济失调性轻瘫，貌似大脑半球病灶定位体征，易导致错误定位。现就MRI证实的貌似半球病变的桥脑腔隙性梗死13例患者分析如下。     

儿童脑静脉窦血栓12例临床特征分析

【摘要】
目的 探讨儿童脑静脉窦血栓形成（cerebral venous sinus thrombosis,CVST）发病的危险因素、病因、临床表现、影像学表现及诊治方法。
方法 对2003年1月至2011年6月在北京天坛医院儿科及神经内科就诊的12例儿童脑静脉窦血栓进行回顾性分析。
结果 所有患儿均表现出颅高压症状。鼻窦炎（7例,58.3%）可能为儿童CVST主要发病病因。颅脑磁共振成像（magnetic resonance imaging,MRI）和磁共振静脉成像（magnetic resonance venography,MRV）显示最常见的受累静脉窦为乙状窦和横窦（各11例,占97.1%）。经降颅压、抗凝及对症支持治疗,8例痊愈,4例遗留神经功能缺损。
结论 CVST患儿常以颅高压症状就诊,感染为儿童CVST的最主要危险因素,神经影像学检查能为确诊提供依据,及时治疗可改善预后。     

血管周围间隙在脑小血管病中的研究进展

血管周围间隙（perivascular spaces,PVS）是脑小血管周围充满液体的潜在腔隙。扩大的血
管周围间隙（enlarged perivascular spaces,ePVS）已成为脑小血管病（cerebral small vessel diseases,CSVD）
公认的影像标志物之一。PVS的量化依赖于MRI,难点在于ePVS与腔隙灶的鉴别。PVS被证明与年龄、
高血压、其他CSVD影像学标志物、认知功能损害、全身性炎症相关,但仍缺乏较为长期的、针对不同
人群的队列研究。研究ePVS与CSVD病程的关系,有助于临床上对CSVD的早期发现和风险预测。     

脑静脉窦血栓形成的MR诊断及MRV的应用

目的探讨脑静脉窦血栓形成（cerebral venous sinus thrombosis, CVST）的MR征象及磁共振脑静脉系血管成像（magnetic resonance venography, MRV）的技术方法。方法4例脑静脉窦血栓形成患者,男2例,女2例,年龄32～51岁,全部经常规MRI及MRV检查,2例患者行增强扫描,全部患者经DSA检查证实。结果4例患者平扫SE序列均可见静脉窦内正常流空信号消失,代之以异常等或高信号。出血性脑梗死3例;广泛脑肿胀及脑水肿1例。MR增强可见静脉窦异常低信号或闭塞;对比增强磁共振血管造影检查（contrast enhanced magnatic resonance venography, CE-MRV）见受累静脉窦腔内血流信号不规则或信号完全消失。结论MRI结合3D-CE-MRA是诊断脑静脉窦血栓形成的有效手段。     

腔隙性脑梗塞患者颅内脑动脉狭窄的检测意义

目的探讨腔隙性脑梗塞与颅内脑动脉狭窄的关系。方法412例腔隙性脑梗塞患者均行经颅多普勒(TCD)检测,发现颅内动脉狭窄后进一步行磁共振血管造影(MRA)检查确诊。结果MRA检查发现颅内动脉狭窄127例。结论腔隙性脑梗塞患者颅内脑动脉狭窄发生率较高,推测其是腔隙性脑梗塞的重要病因。对腔隙性脑梗塞患者应重视检测可能存在的颅内脑动脉狭窄。     

Standard magnetic resonance imaging is inadequate for patients with refractory focal epilepsy

OBJECTIVES: Patients with intractable epilepsy may benefit from epilepsy surgery especially if they have a radiologically demonstrable cerebral lesion. Dedicated magnetic resonance imaging (MRI) protocols as performed at epilepsy surgery centres can detect epileptogenic abnormalities with great sensitivity and specificity. However, many patients with epilepsy are investigated with standard MRI sequences by radiologist outside epilepsy centres ("non-experts"). This study was undertaken to compare standard MRI and epilepsy specific MRI findings in patients with focal epilepsy. METHODS: Comparison of results of standard MRI reported by "non-expert" radiologists, standard MRI evaluated by epilepsy "expert" radiologists, and epilepsy specific MRI read by "expert" radiologists in 123 consecutive patients undergoing epilepsy surgery evaluation between 1996 and 1999. Validation of radiological findings by correlation with postoperative histological examination. RESULTS: Sensitivity of "non-expert" reports of standard MRI reports for focal lesions was 39%, of "expert" reports of standard MRI 50%, and of epilepsy dedicated MRI 91%. Dedicated MRI showed focal lesions in 85% of patients with "non-lesional" standard MRI. The technical quality of standard MRI improved during the study period, but "non-expert" reporting did not. In particular, hippocampal sclerosis was missed in 86% of cases. Neuropathological diagnoses (n=90) were predicted correctly in 22% of "non-expert" standard MRI reports but by 89% of dedicated MRI reports. CONCLUSIONS: Standard MRI failed to detect 57% of focal epileptogenic lesions. Patients without MRI lesion are less likely to be considered candidates for epilepsy surgery. Patients with refractory epilepsy should be referred to an MRI unit with epileptological experience at an early point.     

磁共振关节内增强扫描评价膝关节骨质、半月板、韧带和关节软骨损伤的准确性：与常规磁共振扫描的比较

背景：常规磁共振检查可较为全面地显示关节内软组织的结构，但由于其成像后对比度欠缺等因素，在诊断关节内病变和损伤时仍存在一定的局限性。为了提高诊断的准确率，磁共振的增强扫描已应用于肝脏、脑等其他部位，但有关膝关节增强扫描的报道较少。 目的：评价磁共振关节内增强扫描对膝关节损伤诊断的临床应用价值。 方法：选择21例膝关节损伤患者(22膝)，采用美国GE公司生产的0.5T Signa Contour磁共振扫描仪先进行常规磁共振扫描。常规扫描完成后，向关节内注入增强剂，行关节内增强扫描。所有病例均由同一医师进行关节内增强操作，由两名副主任职称以上的医师进行阅片分析和对比。 结果与结论：所有病例在平扫中均发现有不同程度的关节结构损伤，包括骨质、半月板、韧带和关节软骨等。在磁共振增强扫描后进一步证实，其损伤的程度和范围上得到了更清楚的显示。同时，有2例平扫中误诊的半月板损伤，在增强扫描后得到否定；有的损伤部位在平扫中未发现的病变信号，在关节内增强扫描中被发现和证实。说明增强后磁共振扫描膝关节损伤的阳性率高于常规扫描。其中，增强前后半月板损伤诊断准确率差异有显著性意义(P =0.035)。提示，与常规扫描相比，磁共振关节内增强扫描可进一步提高膝关节损伤的诊断率。     

Face memory in MRI-positive and MRI-negative temporal lobe epilepsy

PURPOSE: Effects of MRI-positive (MRI(+)) as compared to MRI-negative (MRI(-)) temporal lobe epilepsy (TLE) on face memory are not yet known. METHODS: We studied 24 MRI(-) (11 right/13 left) and 20 MRI(+) (13 right/7 left) TLE patients, 12 generalized epilepsy patients, and 12 healthy subjects undergoing diagnostic workup with 24-72-h Video-EEG-monitoring. Twenty faces were shown, and had to be recognized from 40 faces immediately and after a 24-h delay. RESULTS: MRI(+) and MRI(-) right TLE (RTLE) patients showed deficits in face recognition compared to controls or generalized epilepsy, consistent with right temporal lobe dominance for face recognition. MRI(+) RTLE patients had deficits in both immediate and delayed recognition, while MRI(-) RTLE patients showed delayed recognition deficits only. The RTLE groups showed comparable delayed recognition deficits. Separate analyses in which the MRI(+) group included patients with hippocampal sclerosis only, did not alter results. Furthermore, MRI(-) RTLE had a worse delayed recognition than MRI(-) left TLE (LTLE). On the other hand, MRI(+) RTLE did not differ from MRI(+) LTLE in delayed recognition. Combining MRI(-) and MRI(+) TLE groups, we found differences between RTLE and LTLE in delayed, but not immediate face recognition. CONCLUSIONS: Our results suggest that a delayed recognition condition might be superior to immediate recognition tests in detecting face memory deficits in MRI(-) RTLE patients. This might explain why former studies in preoperative patients did not observe an immediate face recognition dominance of the right temporal lobe when combining MRI(-) and MRI(+) TLE patients. Our data further point to an important role of the right mesial temporal region in face recognition in TLE.     

Magnetic resonance imaging in experimental models of brain disorders.

This review gives an overview of the application of magnetic resonance imaging (MRI) in experimental models of brain disorders. MRI is a noninvasive and versatile imaging modality that allows longitudinal and three-dimensional assessment of tissue morphology, metabolism, physiology, and function. MRI can be sensitized to proton density, T1, T2, susceptibility contrast, magnetization transfer, diffusion, perfusion, and flow. The combination of different MRI approaches (e.g., diffusion-weighted MRI, perfusion MRI, functional MRI, cell-specific MRI, and molecular MRI) allows in vivo multiparametric assessment of the pathophysiology, recovery mechanisms, and treatment strategies in experimental models of stroke, brain tumors, multiple sclerosis, neurodegenerative diseases, traumatic brain injury, epilepsy, and other brain disorders. This report reviews established MRI methods as well as promising developments in MRI research that have advanced and continue to improve our understanding of neurologic diseases and that are believed to contribute to the development of recovery improving strategies.     

Foundations of advanced magnetic resonance imaging

During the past decade, major breakthroughs in magnetic resonance imaging (MRI) quality were made by means of quantum leaps in scanner hardware and pulse sequences. Some advanced MRI techniques have truly revolutionized the detection of disease states and MRI can now— within a few minutes—acquire important quantitative information noninvasively from an individual in any plane or volume at comparatively high resolution. This article provides an overview of the most common advanced MRI methods including diffusion MRI, perfusion MRI, functional MRI, and the strengths and weaknesses of MRI at high magnetic field strengths.     

MRI半剂量动态增强在垂体微腺瘤中的诊断价值

目的 评价MRI 半剂量动态增强对垂体微腺瘤的诊断价值.方法 对32 例经实验室、影像学及临床诊断的垂体微腺瘤患者的影像资料进行回顾性分析.结果 平扫的阳性率为53.13%,半剂量动态增强扫描垂体微腺瘤检出率为100.0%,延迟后检出率为75.0%.结论 半剂量动态增强扫描对垂体微腺瘤的检出具有良好的敏感性和特异性,可...     

MRI essentials in epileptology: a review from the ILAE Imaging Taskforce

Magnetic resonance imaging (MRI) plays a central role in the management and evaluation of patients with epilepsy. It is important that structural MRI scans are optimally acquired and carefully reviewed by trained experts within the context of all available clinical data. The aim of this review is to discuss the essentials of MRI that will be useful to health care providers specialized in epilepsy, as outlined by the competencies and learning objectives of the recently developed ILAE curriculum. This review contains information on basic MRI principles, sequences, field strengths and safety, when to perform and repeat an MRI, epilepsy MRI protocol (HARNESS‐MRI) and the basic reading guidelines, and common epileptic pathologies. More advanced topics such as MRI‐negative epilepsy, functional MRI and diffusion‐weighted imaging are also briefly discussed. Although the available resources can differ markedly across different centers, it is the hope that this review can provide general guidance in the everyday practice of using MRI for patients with epilepsy.     

Magnetic Resonance Imaging in Complex Partial Seizures

Abstract: Magnetic resonance imaging (MRI) and computed tomography (CT) were performed on 45 patients with intractable complex partial seizures. MRI was performed with a super conducting whole-body scanner operating at 0.5 tesla (T) and 1.5 T. In patients with temporal lobe epilepsy, 8 of 24 patients had abnormal CT, but 16 of 24 patients showed abnormal MRI. 1.5 T MRI detected more abnormality than 0.5 T MRI when CT was normal. In patients with frontal lobe epilepsy, 5 of 7 patients had normal CT and MRI. In 2 other patients, MRI demonstrated an arachnoid cyst and increased signal intensity area on the T2-weighted images, which were not detected by CT. In patients with occipital lobe epilepsy, 5 of 6 patients show abnormal CT and MRI. In patients with tuberous sclerosis, MRI revealed some increased signal intensity areas on the T2-weighted images in the occipital and temporal lobe, which were not detected by CT. Most surface EEG foci corresponded with the side of MRI abnormality. These data indicate that MRI is more informative than CT in complex partial seizures. MRI is the imaging technique of choice in the diagnosis of complex partial seizures.     

Magnetic resonance imaging in complex partial seizures

Magnetic resonance imaging (MRI) and computed tomography (CT) were performed on 45 patients with intractable complex partial seizures. MRI was performed with a superconducting whole-body scanner operating at 0.5 tesla (T) and 1.5 T. In patients with temporal lobe epilepsy, 8 of 24 patients had abnormal CT, but 16 of 24 patients showed abnormal MRI. 1.5 T MRI detected more abnormality than 0.5 T MRI when CT was normal. In patients with frontal lobe epilepsy, 5 of 7 patients had normal CT and MRI. In 2 other patients, MRI demonstrated an arachnoid cyst and increased signal intensity area on the T2-weighted images which were not detected by CT. In patients with occipital lobe epilepsy, 5 of 6 patients show abnormal CT and MRI. In patients with tuberous sclerosis, MRI revealed some increased signal intensity areas on the T2-weighted images in the occipital and temporal lobe, which were not detected by CT. Most surface EEG foci corresponded with the side of MRI abnormality. These data indicate that MRI is more informative than CT in complex partial seizures. MRI is the imaging technique of choice in the diagnosis of complex partial seizures.     

磁共振动态增强扫描对诊断垂体微腺瘤的价值

目的评价磁共振动态增强扫描诊断垂体微腺瘤的价值。方法对26例垂体微腺瘤患者的磁共振平扫、动态增强扫描、常规延迟增强扫描影像学资料进行回顾性分析。结果磁共振平扫、动态增强扫描和常规延迟增强扫描微腺瘤检出率分别为53．85％（14／26），100％（26／26），和73．08％（19／26），三种不同的扫描方法微腺瘤检出率有显著差异（P〈0．01）。结论磁共振动态增强扫描能明显提高垂体微腺瘤的捡出率，对垂体微腺瘤的诊断有重要价值。