神经梅毒26例磁共振成像表现

目的 分析不同临床类型神经梅毒的MRI表现.方法 回顾性研究26例神经梅毒患者的临床及MRI资料,描述各种临床类型神经梅毒的MRI表现.结果 26例神经梅毒患者中,17例MRI有异常表现.其中脑膜血管型梅毒7例,主要表现为脑部多发的缺血灶、梗死灶,少数表现为脑炎样改变;麻痹性痴呆6例,主要表现为额、颞叶萎缩,少数伴有脑缺血灶、颗粒性室管膜炎及海马硬化;脊髓膜血管梅毒3例,主要表现为下颈段至下胸段脊髓轻度肿胀,其内可见多发的缺血灶;脊髓痨1例,其脑部MRI表现为缺血灶.9例患者MRI表现正常,其中脑膜型梅毒4例,脊髓痨5例.结论 不同临床类型神经梅毒的MRI表现具有一定特征,但缺乏特异性,临床上容易误诊.     

Gadolinium-enhanced magnetic resonance imaging of the central nervous system in systemic lupus erythematosus

Summary Gadolinium (Gd)-DTPA enhanced magnetic resonance imaging (MRI) was performed in 15 systemic lupus. erythematosus patients with past (12) or present (3) features suggesting central nervous system (CNS) involvement. Symptomatic Gd-DTPA enhancing lesions were seen in 2 patients, and immunosuppressive treatment was associated with a rapid reversal of enhancement. The pattern of enhancement was different from that usually seen in multiple sclerosis. Gd-DTPA enhanced MRI may sometimes be useful in demonstrating the activity of CNS lupus.     

Magnetic resonance imaging of dysraphic myelodysplasia

The spinal cord in 56 children and adolescents was examined by magnetic resonance imaging (MRI) many years after neonatal surgery on a meningomyelocele (average age 12 years). In a high percentage of cases, the diagnosis tethered cord was made. Associated anomalies were found with a frequency of 21%. Typical findings are presented and the impact of these results on therapy planning is discussed.     

免疫正常人原发性脑淋巴瘤的MR表现

目的 探讨免疫正常人原发性脑淋巴瘤的MR表现及其诊断价值. 方法 回顾性分析经手术病理证实的15例免疫正常人脑淋巴瘤的MR资料,患者均行常规MR平扫和增强检查. 结果 15例患者共有18个病灶,14个在幕上,4个在幕下.7个病灶有明显的坏死囊变或出血.2例出现柔脑膜转移.在MR的T1WI、T2WI图像上15个病灶实质呈等信号,增强后所有病灶实质呈明显均匀强化,17个病灶表现轻中度占位效应. 结论 免疫正常人原发性脑淋巴瘤幕上多见,MR的T1WI、T2WI图像上肿瘤实质呈等信号,增强后明显均匀强化,有轻度中度占位效应,具有一定特征性.     

磁共振成像在多发性肌炎、皮肌炎诊断中的应用

目的 研究多发性肌炎(PM)、皮肌炎(DM)的磁共振成像(MRI)表现，评价MRI在PM及DM诊断中应用价值。方法 对5例PM及4例DM患者行MRI检查，选择骨盆、双侧大腿及小腿肌肉，采用自旋回波序列(SE)、快速自旋回波序列(FSE)及短时反转恢复序列(STIR)进行扫描。结果 5例PM及4例DM患者的受累肌群均表现为斑片状等T1长T2异常信号，2例PM患者尚可见小斑片状短T1长T2异常信号影；6例患者肌筋膜增厚，呈长T2线样高信号改变；4例DM患者的表皮及皮下结缔组织尚可见条带状及网格状长T1长T2异常信号影。受累肌群主要表现为炎症水肿样改变，晚期受累肌肉可见少量脂肪替代改变；病变双侧不对称，以内收肌受累最重，股中间肌受累最轻。结论 PM与DM患者的MRI表现具有一定的特征性，MRI能为PM及DM的定位诊断、疗效判断及病情随访提供客观资料，并能为临床选取准确的活检部位提供帮助。     

Magnetic resonance imaging in multiple sclerosis: the role of conventional imaging

Magnetic resonance imaging (MRI) of the brain and spinal cord plays a central role in establishing the diagnosis of multiple sclerosis (MS), in monitoring disease activity, and as a key outcome measure in clinical trials of new MS therapies. Conventional MRI continues to evolve, reflecting advances in imaging hardware and software. These advances have led to important new insights into MS disease pathophysiology and can be used to improve patient management. Despite these improvements, standard MRI continues to capture only a small portion of the underlying changes that occur during the course of the disease.     

Magnetic resonance imaging in right hemisphere cerebellitis associated with homolateral hemiparesis

We present a sequence of magnetic resonance images (MRI) of a patient with cerebellitis, taken from the onset of symptoms until their disappearance 9 months later. The need to perform MRI rather than computed tomography in all patients suspected of having cerebellitis or other posterior fossa lesions is suggested     

Magnetic resonance imaging in spinocerebellar ataxias

Magnetic resonance (MR) imaging is widely used to visualize atrophic processes that occur during the pathogenesis of spinocerebellar ataxias (SCAs). T1-weighted images are utilized to rate the atrophy of cerebellar vermis, cerebellar hemispheres, pons and midbrain. Signal changes in the basal ganglia and ponto-cerebellar fibers are evaluated by T2-weighted and proton density-weighted images. However, two-dimensional (2D) images do not allow a reliable quantification of the degree of atrophy. The latter is now possible through the application of three-dimensional (3D) true volumetric methods, which should be used for research purposes. Ideally, these methods should allow automated segmentation of contrast-defined boundaries by using region growing algorithms, which can be applied successfully in structures of the posterior fossa and basal ganglia. Thin slice thickness helps to minimize partial volume effects. Whereas volumetric approaches rely on predetermined anatomical boundaries, voxel-based morphometry has been developed to determine group differences between different types of SCA (cross-sectional studies) or within one SCA entity (longitudinal studies). We will review recent results and how these methods are currently used to (i) separate sporadic and dominantly inherited forms of cerebellar ataxias; (ii) identify specific SCA genotypes; (iii) correlate patho-anatomical changes with SCA disease symptoms or severity; and (iv) visualize and estimate the rate of progression in SCA.     

Magnetic resonance imaging analysis of extremely slow flow in a model shunt system

Shunt malfunction is common and its diagnosis may require invasive testing that may be inaccurate or result in complications. Magnetic resonance imaging (MRI) may prove to be a useful noninvasive test of shunt function as it has been shown that MRI is capable of measuring cerebrospinal fluid (CSF) flows from 2 ml/h to 40 ml/h in model systems. Since flows in functioning shunt systems can be less than 2 ml/h, MRI must be sensitive enough to detect flow in this range in order to be a valid test for shunt function. Continuing previous studies, we have studied MRI flow-related enhancement at flow rates from 0 to 2 ml/h. Multiple spin echo scans (TR2000, TE20) were made through a specialized section of tubing in a model shunt system. The intensity of the MRI signal at points known to demonstrate maximal flow-related enhancement was measured. A linear relationship was demonstrated between signal intensity and flow as low as 0.8 ml/h. These results add support to the concept that MRI is sensitive enough to detect the lowest flows present in functioning shunt systems and therefore may be useful as a noninvasive test of shunt function.     

静息态功能磁共振成像观察阿尔茨海默病患者大脑自发活动特点

目的 运用静息态功能磁共振成像(fMRI)技术探测老年阿尔茨海默病(AD)患者大脑自发活动特点.方法 选择23例AD患者(AD组)和21名健康志愿者(NC组),分别接受神经心理学检查(MMSE、听觉词语学习测试)和静息态fMRI扫描,比较两组间神经心理评分和局部一致性(ReHo)的差异.结果 AD组(分)MMSE(20±4)、听觉词语学习测试即刻回忆(2.6±1.6)、延迟回忆(0.4±0.7)及再认成绩(5.8±3.7)均低于NC组(29±1、5.9±1.2、5.5±2.0、9.2±1.1,T=10.58、7.21、10.99、3.96,均P＜0.01);当设置单个体素统计阈值为P＜ 0.01、激活簇≥100体素时,与NC组比较,AD组在前额叶内侧面、后扣带回及楔前叶、右侧颞上回、两侧顶上小叶及顶下小叶等默认网络脑区ReHo值降低;在左侧壳核、丘脑的ReHo值增高.结论 AD患者存在大脑默认功能网络异常;而在壳核、丘脑的自发活动增强,可能是大脑皮质下结构对默认系统功能降低的代偿反应.     

Magnetic resonance and CT imaging of diastematomyelia

Summary The clinical, MRI and CT features of diastematomyelia with an uncommon clinical course are reported. Possible pathogenetic aspects in the late onset of symptoms are discussed implying vascular factors. MRI provides direct visualization of the split cord and low conus, confirming that frontal images are preferable.     

磁共振弥散张量成像在诊断中枢神经系统疾病的初步应用

目的 探讨磁共振(MRI)弥散张量成像(DTI)对中枢神经系统疾病的脑白质改变的诊断价值。方法 对10名健康志愿者和64例神经系统疾病患者(脑血管病31例，脱髓鞘疾病7例，炎症7例，肿瘤10例，变性病和先天性发育不良各2例，脑萎缩3例，其他2例)进行MRI检查，包括常规T1WI,T2WI,T2Flair,EWI以及ETI序列。并分别测量FA值。结果 本组59例(92．1％)可见病变区脑白质纤维束消融，FA值减低；12例(20．3％)可见边界清楚的侵蚀状改变，肿瘤病例均可见病变区域旁的白质纤维束推压和移位。结论 DTI可早期发现白质内的病变。与传统MRI相比，DTI能更好地显示脑白质纤维束的受损和移位。     

Plasma cerebrosterol and magnetic resonance imaging measures in multiple sclerosis

OBJECTIVES: The concentration in plasma of the brain-specific cholesterol metabolite cerebrosterol has been proposed as a biomarker of neurodegeneration in multiple sclerosis (MS) and other neurological diseases. It is unknown, however, which pathophysiological process in MS best accounts for variations in plasma cerebrosterol. PATIENTS AND METHODS: In this study, we related plasma cerebrosterol concentrations in 46 MS patients - 27 with a relapsing-remitting (RR) disease course and 19 with a primary progressive (PP) course - to three conventional magnetic resonance imaging measures: on T(1)-weighted brain scans, volume of gadolinium-enhanced lesions (a marker of active inflammation) and hypointense lesions (a marker of edema or axonal loss) and on T(2)-weighted scans, volume of hyperintense lesions (a marker of disease extent). RESULTS: By multiple-regression analysis, we uncovered negative correlations between the cerebrosterol-cholesterol ratio in plasma and both age at sampling (beta=-0.35 and p=0.079 in RRMS; beta=-0.76 and p=0.006 in PPMS) and volume of T(2)-weighted lesions (beta=-0.52 and p=0.078 in RRMS; beta=-0.50 and p=0.247 in PPMS). CONCLUSION: We hypothesize that decreases in plasma cerebrosterol may reflect the total spatiotemporal burden of MS-the cumulative effects of its dissemination in space and its duration in time.     

Magnetic resonance imaging follow-up in Creutzfeldt-Jakob disease

Summary The history of a 67-year-old woman with histologically proven Creutzfeldt-Jakob disease (013) is presented. Before typical clinical and neurophysiological signs of CJD developed, magnetic resonance imaging (MRI) showed slightly enhanced signal intensity of the caudate nuclei and putamina in T2-weighted and proton density images, corresponding to spongiform degeneration in neuropathological examination. Five weeks later characteristical progressive cortical atrophy was demonstrated by follow-up MRI.     

Magnetic resonance imaging of the brain and spine

Summary The efficacy of magnetic resonance imaging (MRI) in the diagnosis of diseases of the central nervous system is reviewed. MRI, computed tomography (CT) and certain radionuclide studies are compared in the evaluation of intracranial tumours, cerebral vascular disease, multiple sclerosis and other white matter diseases, dementia, head injury, infection, epilepsy, spinal lesions and in paediatric central nervous system disorders. The measurement of cerebrospinal fluid volumes and dynamics by MRI is discussed. MRI most clearly has advantages where CT is degraded by bone hardening and streak artefacts (spine, skull base, posterior and temporal fossa, sella and parasellar regions) and in diseases in which the X-ray attenuation of the suspected lesion differs little from normal parenchyma (paediatric brain disorders, demyelination and dysmyelination, early oedema associated with infarction, infection or low-grade infiltrating neoplasm, subacute and chronic haemorrhage and lesions in the spinal subarachnoid space and cord). Elsewhere MRI and CT should be seen as complementary rather than competitive methods of imaging. In spite of an absence of information about the contribution of MRI to management decisions and a lack of rigorous, prospective controlled trials, MRI will play an increasing role in the diagnosis of diseases of the central nervous system.     

Magnetic resonance imaging of the child's brain

The most significant difference between magnetic resonance imaging (MRI) and computed tomography (CT) is that the former graphic representation of the cerebrospinal axis and its structures does not use ionizing radiation or the injection of contrast material. The physical principles of MRI and the very characteristic appearances of some pathological processes common in children require special study. Low-proton density areas are generally dark; the short T ₁ value is responsible for white matter appearing clear; inversion recovery sequences permit study of the progression of myelination.     

磁共振弥散加权成像评价机械性取栓的实验研究

目的 应用磁共振弥散加权成像(DWI)技术评价机械性取栓治疗栓塞性脑梗死的疗效。 方法 40只新西兰兔颈内动脉注入血凝块栓子制备急性栓塞性脑梗死模型后按随机数字表法分为非治疗组（不做任何治疗）、6h机械取栓组、8h机械取栓组、12h机械取栓组（分别于制模成功后6h、8h、12h在DSA导引下经股动脉插管机械取栓）,每组10只,各组分别在6h、8h、12h、24h行DWI并计算各时段表观弥散系数(ADC)和梗死体积。 结果 兔脑梗死超急性期（6 h内）均在DWI上显示缺血区,表现为高信号,在T1WI、T2WI上表现为正常信号;T1WI、T2WI及DWI对急性期(24h内)脑梗死的检出率差异有统计学意义(P＜0.05)。非治疗组、12h机械取栓组在急性期内ADC值逐渐降低,梗死体积逐渐扩大,而6h、8h机械取栓组在急性期取栓后ADC值逐渐上升,梗死体积缩小。梗死后24h,与非治疗组和12h机械取栓组比较,6h和8h机械取栓组ADC值较高,梗死体积较低,差异均有统计学意义(P＜0.05)。 结论 栓塞性脑梗死早期机械性取栓效果显著,DWI是动态观察急性脑梗死治疗效果的敏感影像学手段。     

Magnetic resonance imaging of muscle and brain in myotonic dystrophy

Myotonic dystrophy (MD) is characterized by myotonia, weakness and extramuscular symptoms, including intellectual impairment. We performed magnetic resonance imaging (MRI) of brain and muscle in 25 MD patients: 81% had cerebral atrophy (severe in 36%); 68% had focal white matter lesions, which were large and multiple in 27%. Brain MRI findings correlated with mental impairment; the severity of both correlated with disease duration. Changes in brain and muscle MRI were progressive with time, but independent of each other. Muscle MRI findings were fatty degeneration and loss of bulk. In the calves, the medial gastrocnemius muscles were involved earliest and the posteriortibial muscles relatively spared. In the thighs the vastus muscles were damaged most often and the rectus femoris least. Focal muscle damage was efficiently visualized, sometimes preceding clinical detection. Muscle MRI was less sensitive than conventional methods for early diagnosis, but ideal for follow-up, owing to its non-invasiveness and examiner-independence.     

Magnetic resonance imaging in motor neuron disease

Summary Magnetic resonance imaging (MRI) of the brain was evaluated in 20 patients with motor neuron disease (MND) and in a control group of 11 healthy people. Bilateral increased signal areas of various sizes in the centrum semiovale, corona radiata, internal capsule, pedunculi of midbrain, pons, medulla and even in the frontal lobe, topographically related with the corticospinal tract, were found in 8 out of 20 patients. Three out of 4 patients with progressive bulbar paralisis and 5 out of 11 cases of amyotrophic lateral sclerosis had abnormal MRI. Such MRI abnormalities have neither been found in patients with progressive muscular atrophy nor in controls, suggesting that they may be the hallmark of pyramidal tract degeneration in motor neuron disease.     

部分性发作癫痫患者静息状态功能磁共振默认模式网络的功能连接改变

目的 应用静息状态功能磁共振成像(fMRI)探讨部分性发作癫痫患者静息状态下的脑功能改变.方法 对60例部分性发作癫痫患者(患者组)和60名性别、年龄和教育程度匹配的健康对照者(对照组),使用3.0T磁共振采集两组的静息状态下fMRI数据,采用功能连接方法分析计算脑区的默认模式网络的功能连接,利用SPM5软件分析比较患者组和对照组脑功能的差异.结果 患者组的默认模式网络的功能连接主要包括左侧楔前叶/后扣带回和角回、扣带回;对照组的功能连接主要包括左侧楔前叶/后扣带回和右侧角回,双侧内侧额叶和颞叶;患者组的左侧顶下小叶[坐标值(x,y,z):-57,-39,48;t=4.90,P＜0.01]、左侧缘上回[坐标值(x,y,z):-63,- 48,33;t=4.25,P＜0.01]、左侧海马旁回[坐标值(x,y,z):-30,-6,-21;t =4.05,P＜0.01]、左侧颞上回[坐标值(x,y,z):-48,-39,6;t=3.72,P＜0.01],左侧钩回[坐标值(x,y,z):-24,6,- 36;=4.56,P＜0.01]及右侧钩回[坐标值(x,y,z):33,-15,- 36;t=4.00,P＜0.01]的默认模式网络功能连接较对照组降低;未发现功能连接升高的脑区.结论 部分性发作癫痫患者静息状态下脑区的功能连接改变,可能是部分性发作癫痫潜在的病理生理机制.静息状态fMRI能发现常规MRI正常的癫痫患者的广泛脑功能异常,是一种无创的研究癫痫患者脑功能的有效方法.