Multiple ring-enhancing lesions of the brain

Multiple ring-enhancing lesions of the brain are one of the most commonly encountered abnormalities on neuroimaging. These can be caused by a variety of infectious, neoplastic, inflammatory or vascular diseases. Distinguishing non-neoplastic causes from neoplastic lesions is extremely important because a misdiagnosis can lead to unwarranted neurosurgery and exposure to toxic chemotherapy or potentially harmful brain irradiation. Diligent clinical evaluation and a battery of tests are required for making a definitive diagnosis. Newer advanced diagnostic techniques, such as diffusion-weighted magnetic resonance imaging (MRI), perfusion-weighted MRI, magnetic resonance spectroscopy, single-photon emission tomography and positron emission tomography may help in establishing the etiology. However, early brain biopsy is often needed because several of these diseases are potentially life-threatening.     

Clinical and neuroimaging findings in MOGAD–MRI and OCT

Myelin oligodendrocyte glycoprotein antibody‐associated disorders (MOGAD) are rare in both children and adults, and have been recently suggested to be an autoimmune neuroinflammatory group of disorders that are different from aquaporin‐4 autoantibody‐associated neuromyelitis optica spectrum disorder and from classic multiple sclerosis. In‐vivo imaging of the MOGAD patient central nervous system has shown some distinguishing features when evaluating magnetic resonance imaging of the brain, spinal cord and optic nerves, as well as retinal imaging using optical coherence tomography. In this review, we discuss key clinical and neuroimaging characteristics of paediatric and adult MOGAD. We describe how these imaging techniques may be used to study this group of disorders and discuss how image analysis methods have led to recent insights for consideration in future studies.     

Somato-motor inhibitory processing in humans: evidence from neurophysiology and neuroimaging

Motor execution processing has been examined using an index of behavioral performance such as reaction times, kinetics, and kinematics. However, difficulties have been associated with the study of motor inhibitory processing because of the absence of actual behavioral performance. Therefore, non-invasive neurophysiological and neuroimaging methods including electroencephalography, magnetoencephalography, transcranial magnetic stimulation, and functional magnetic resonance imaging have been used to investigate neural processes in the central nervous system. We mainly reviewed research on somato-motor inhibitory processing based on data obtained by using these techniques, which can examine ‘when’, ‘where, and ‘how’ motor inhibition occurs in the brain. Although to date a number of studies have used these techniques separately, few studies have utilized them in a comprehensive manner. In this review, we provide evidence that combining neurophysiological and neuroimaging methods should contribute to our understanding of how executive and inhibitory functions are implemented.     

Clinicocytopathology of breast cancers with a ring-like appearance on ultrasonography and/or magnetic resonance imaging

On breast cancer imaging some cancers have an anechoic or high-echoic zone in the tumor on ultrasonography and ring-shaped enhancement on contrast-enhanced magnetic resonance imaging (MRI) with high intensity in the central area of the tumor on T2-weighted imaging, necessitating their differentiation from benign disease. Thus, nine breast cancers with a ring-like appearance on imaging were analyzed on cytopathology. Histologically the cancer cells of these lesions showing a ring-like appearance were located in the periphery of the tumor, with a central hypocellular zone. Five such lesions with a thick, doughnut-like appearance were identified as cancers with acellular zones (CAC), and four lesions with a thinner, rim-like appearance as matrix-producing carcinomas (MPC). The percentage ratio of the cancer-zone width to the tumor diameter was 26.4 ± 7.8 and 8.0 ± 3.2 (mean ± SD), respectively ( P = 0.003). Cytologically, highly atypical, naked-nucleus cells were observed in eight of the nine cancers. In two MPC and three CAC, cartilage matrix and amorphous material, respectively, were observed in the background. In summary, the present series of breast cancers having a ring appearance on imaging did not have uniform cytopathological features. They were classified as MPC or CAC, and cytology was useful in their diagnosis and differentiation in some cases.     

Optimizing clinical monitoring of central nervous system involvement in SLE

Central Nervous System (CNS) involvement is a frequent SLE manifestation occurring in 15-75% of patients. However, diagnosis of CNS involvement is a difficult task and requires a careful clinical and laboratory assessment along with instrumental evaluation. In recent years major advances in neuroimaging techniques allowed a great improvement in our understanding of SLE pathogenesis. Anyway, since no single imaging technique covers all brain pathology and both inflammation and neurodegeneration contribute to SLE pathogenesis, it is very important to use a multimodality approach coupling a morphological with a functional imaging modality. In this setting, to date, conventional magnetic resonance imaging and single photon emission computed tomography are the most largely available and accessible techniques. Modern techniques such as perfusion weighted imaging, diffusion weighted imaging, magnetization transfer imaging and magnetic resonance spectroscopy provide useful information to assess brain tissue damage however, their clinical relevance in individual patients needs further evidence. In this review we would like to summarize what have we learned in the last few years about neuroimaging in NPSLE, what have been major advances in neuroimaging techniques and, finally, we would like to give some suggestions about what should be done in daily clinical practice to approach SLE patients with NP symptoms.     

Neuroimaging and functional analyses for multiple sclerosis

For neuroimaging studies of multiple sclerosis(MS) lesions, magnetic resonance imaging (MRI) is most useful, while evoked potentials(EPs) are commonly used for functional analyses of neural damage due to MS. This review summarizes the MRI and EP findings in MS. MS lesions are visualized as high signal intensity lesions on T2-weighted images, proton density(PD)-weighted images, and fluid-attenuated inversion recovery(FLAIR) images, while such lesions demonstrate a low signal on T1-weighted images. New MS lesions are usually enhanced by gadolinium-DTPA on T1-weighted images, and the enhancement generally lasts 4 to 8 weeks. In Asian patients with MS, opticospinal MS(Asian-type MS) shows a significantly smaller numbers of brain MRI lesions than conventional MS(Western-type MS), while opticospinal MS shows a significantly higher frequency of the spinal cord atrophy on MRI than conventional MS. EPs are useful for detecting lesions located in certain portions of the central nervous system. MRI is not sensitive enough to detect small lesions in the optic nerves and spinal cord, whereas EPs are sensitive for optic nerve and spinal cord lesions. Thus, combined use of MRI and EPs is required for the diagnosis and the optimal monitoring of disease activity in MS.     

颅内多发病变的临床病理学分析

目的 探讨颅内多发病变的临床病理学特征。方法 对2005年1月至2009年12月期间在首都医科大学宣武医院接受治疗病例中,影像学上为颅内多发病变的62例患者的临床、影像以及病理学资料进行回顾性分析。结果 62例中男32例,女30例,平均发病年龄37.4岁,平均病程11.6个月。病灶可累及大脑半球各叶、基底节区、脑干和小脑等部位,以幕上受累较为多见。病理检查结果为：胶质瘤13例,转移瘤13例,中枢神经系统感染12例,免疫介导的炎性脱髓鞘病8例,中枢神经系统原发淋巴瘤5例,血管炎3例,线粒体脑病2例,静脉窦血栓形成2例,Rosai-Dorfman病2例,放射性脑病2例。其中,线粒体脑病、静脉窦血栓形成以皮层受累为主,转移瘤和血源性感染主要累及灰白质交界区,胶质瘤、脱髓鞘疾病和放射性脑病以白质病变为主,血管炎表现为皮层和皮层下白质的病变。结论 多种肿瘤和非肿瘤性疾病在影像学上可以表现为颅内多发病变,其中以胶质瘤、转移瘤和中枢神经系统感染较为多见。积极开展颅内多发病变脑组织活检,临床、影像与病理学密切结合,是提高颅内多发病变诊断水平行之有效的方法。     

Neuroimaging biomarkers of epileptogenesis

Much progress has been made in the field studying the process of epileptogenesis via neuroimaging techniques. Conventional imaging methods include magnetic resonance imaging with morphometric analysis, magnetic resonance spectroscopy and positron emission tomography. Newer network-based methods such as diffusion tensor imaging and functional magnetic resonance imaging with resting functional connectivity are being developed and applied to clinical use. This review provides a brief summary of the major human and animal studies in both partial and generalized epilepsies that demonstrate the potential of these imaging modalities to serve as biomarkers of epileptogenesis.     

Decreasing incidence of sudden death due to undiagnosed primary central nervous system tumors

CONTEXT: Although most fatal brain tumors are diagnosed well before a patient's death, occasionally medical examiners and coroners encounter cases in which the presence of a primary tumor of the central nervous system (CNS) was not suspected prior to death. Analysis of such cases can shed light on specific pitfalls hindering the diagnosis of brain tumors. In addition, by analyzing the incidence of these cases in a large autopsy series, one can draw conclusions about the evolving effectiveness of medical diagnosis. OBJECTIVE: To determine the incidence of deaths due to undiagnosed primary CNS tumors in the era of advanced neuroimaging techniques. DESIGN: Records from forensic autopsies performed during a 20-year period (1980-1999) at the Office of the Chief Medical Examiner of the State of Maryland were reviewed to identify cases in which death was caused by primary CNS tumors undiagnosed prior to the patient's death. RESULTS: We present 11 cases of undiagnosed primary CNS tumors resulting in sudden death that were identified among 54 873 forensic autopsies. Sudden deaths due to undiagnosed CNS neoplasms account for a significantly lower percentage of cases in our study (0.02%) than in similar series reported prior to 1980 (> or =0.16%). CONCLUSIONS: We hypothesize that improvements in imaging techniques, notably the introduction of computed tomography and magnetic resonance imaging, have resulted in increased early detection of CNS neoplasms. However, vague or short-term symptoms and limited health care access can dissuade patients from seeking medical attention and result in failure to diagnose these tumors correctly.     

Gastrointestinal stromal tumor arising from anorectum: correlation of imprint cytology and radiologic imaging

The diagnosis of gastrointestinal stromal tumor (GIST) is generally established on histopathologic examination of surgical specimens. Gastrointestinal stromal tumor comprises a heterogenous group of neoplasms of the gastrointestinal tract previously referred to as leiomyomas, leiomyosarcomas, or schwannomas. Gastrointestinal stromal tumor arising from anorectum is a rare instance. We report a case of GIST for the correlation of imaging and cytologic features with immunocytochemical staining. A computed tomography and magnetic resonance imaging confirmed a 2-cm tumor growing into the rectal lumen. The central portion of the tumor showed T1-weighted imaging of low signal and suspected central necrosis by the T2-weighted imaging of high signal. Imprint cytology from excised tumors showed isolated or loosely aggregated spindle cells with scanty and fibrillary cytoplasmic processes, nuclear pleomorphism, fine granular chromatin, and irregular nuclear margins. Epithelioid tumor cells showed grooves with abundant cytoplasm and several round nucleoli. Both c-kit and CD34 antigen were positive with strong and diffuse stainability in smears as well as paraffin sections by immunoperoxidase staining. We suggest that the combined use of imaging diagnosis and cytology with immunocytochemical staining are useful initial diagnosis of GIST.     

von Hippel-Lindau disease: surveillance strategy for endolymphatic sac tumors

PurposeUp to 16% of patients with the hereditary von Hippel-Lindau disease develop endolymphatic sac tumors of the inner ear. Early diagnosis and treatment of endolymphatic sac tumors can prevent audiovestibular morbidity, but optimal endolymphatic sac tumor surveillance strategy has yet to be determined. We aimed to evaluate endolymphatic sac tumor surveillance to determine the best surveillance strategy.MethodsIn a national prospective study, 40 VHL mutation carriers were interviewed about audiovestibular symptoms and had audiological examinations and magnetic resonance imaging of the inner ear. Further, we performed a meta-analysis including all reported endolymphatic sac tumor von Hippel-Lindau disease cases in the literature (N = 140 with 156 endolymphatic sac tumors).ResultsIn the prospective study, endolymphatic sac tumors were suspected based on audiovestibular symptoms, audiometry, and magnetic resonance imaging in 34%, 30%, and 12.5% of subjects, respectively. In total, more than 90% of radiologically diagnosed endolymphatic sac tumors were associated with abnormal audiometric findings. No endolymphatic sac tumor genotype-phenotype correlations were found.ConclusionWe recommend annual audiometry as a first-line endolymphatic sac tumor screening tool, and in countries where periodic surveillance magnetic resonance imaging of the central nervous system is performed, specific images of the inner ear should be included. Audiometric abnormalities in patients with von Hippel-Lindau disease without magnetic resonance imaging-visible endolymphatic sac tumors could be due to microscopic endolymphatic sac tumors. Determination of audiometric endolymphatic sac tumor characteristics could further target screening and improve endolymphatic sac tumor diagnosis.     

磁共振检查对冯·希佩尔·林道综合征诊断的意义

目的 分析VHL的磁共振影像特征,评价其对手术治疗的指导意义。方法 回顾性分析本院2006年2月~2017年10月16例经病理及影像证实为VHL综合征患者的临床及多部位磁共振资料,并总结其临床及MRI表现,探讨本病的诊断思路。结果 16例中女性11例,男性5例,年龄7~49岁,平均年龄（25.32±8.14）岁,12例有家族患病史。16例中有15例合并中枢神经系统血管母细胞瘤,病变位于小脑10例,位于脊髓3例,同时受累2例（MRI表现多呈“大囊肿伴壁结节”混合肿块）,5例为首发病变;7例合并视网膜母细胞瘤,其中左侧2例,右侧3例,其中2例为首发病变,平扫T1和FLAIR信号高于玻璃体,T2呈等、高信号,增强扫描病变实性部分明显强化,少数轻度强化;10例合并肾透明细胞癌和肾囊肿,肾癌单发3例、多发6例,一侧肾多发2例,双侧肾多发4例,肾癌平扫时T1WI呈等或低信号,T2WI呈高信号,可伴有囊变及钙化,增强扫描病灶明显强化,肾囊肿表现为无强化的多个薄壁液性病灶;7例合并胰腺多发囊肿,其中2例为首发病变,胰腺囊肿表现为无强化的多个薄壁液性病灶;7例合并嗜铬细胞瘤,其中3例为首发病变,平扫时T1WI以低信号、T2WI以高信号为主,增强扫描实质部分明显强化;其他还合并肾血管平滑肌脂肪瘤、肝血管瘤等。结论 VHL综合征具有一定遗传倾向,常累及多个系统及器官,最常见以中枢神经系统血管母细胞瘤及内脏病变为首发病变;磁共振成像具有多参数任意方位成像、软组织分辨力高、无电离辐射等优点,联合多部位MRI检查有利于VHL综合征的早期诊断,可提高患者的生存质量及生存期。     

A metabolomic data fusion approach to support gliomas grading

Magnetic resonance imaging (MRI) is the current gold standard for the diagnosis of brain tumors. However, despite the development of MRI techniques, the differential diagnosis of central nervous system (CNS) primary pathologies, such as lymphoma and glioblastoma or tumor‐like brain lesions and glioma, is often challenging. MRI can be supported by in vivo magnetic resonance spectroscopy (MRS) to enhance its diagnostic power and multiproject‐multicenter evaluations of classification of brain tumors have shown that an accuracy around 90% can be achieved for most of the pairwise discrimination problems. However, the survival rate for patients affected by gliomas is still low. The High‐Resolution Magic‐Angle‐Spinning Nuclear Magnetic Resonance (HR‐MAS NMR) metabolomics studies may be helpful for the discrimination of gliomas grades and the development of new strategies for clinical intervention. Here, we propose to use T₂‐filtered, diffusion‐filtered and conventional water‐presaturated spectra to try to extract as much information as possible, fusing the data gathered by these different NMR experiments and applying a chemometric approach based on Multivariate Curve Resolution (MCR). Biomarkers important for glioma's discrimination were found. In particular, we focused our attention on cystathionine (Cyst) that shows promise as a biomarker for the better prognosis of glioma tumors.     

rs-fMRI、DTI及1H-MRS在阿尔茨海默病中的应用进展

随着磁共振成像技术的飞速发展,对阿尔茨海默病的神经影像学研究也越来越深入。其主要目的是通过磁共振影像学特征来识别出早期阿尔茨海默病患者,从而达到早期诊断和治疗的目的。本文就磁共振成像技术包括静息态功能磁共振成像、弥散张量成像及磁共振波谱在阿尔茨海默病的应用进展进行综述。     

Degos disease: A radiological-pathological correlation of the neuroradiological aspects of the disease

Malignant atrophic papulosis (Degos disease) is an unusual thrombotic microangiopathy of uncertain etiology. The disease characteristically involves the skin and internal organs, with nervous system involvement more common in children. We present a case with diverse neurological manifestations including cranial nerve palsies, gait instability, and urinary incontinence. The patient also developed white papular lesions on her lower extremities and back. Magnetic resonance imaging (MRI) demonstrated progressive intracranial and spinal abnormalities. Despite treatment with numerous biologic agents, the patient had persistent clinical deterioration and expired one month after admission. We highlight the extensive neurologic manifestations of Degos disease correlated with neuroradiological imaging and pathological features. Nervous system involvement in Degos disease requires careful neurologic and dermatologic exam with central nervous system (CNS) magnetic resonance imaging to distinguish it from non-organic etiologies of similar symptoms.     

Serial evaluation of patients with brain tumors using volume MRI and 3D 1H MRSI.

Patients with brain tumors are routinely monitored for tumor progression and response to therapy using magnetic resonance imaging (MRI). Although serial changes in gadolinium enhancing lesions provide valuable information for making treatment decisions, they do not address the fate of non-enhancing lesions and are unable to distinguish treatment induced necrosis from residual or recurrent tumor. The introduction of a non-invasive methodology, which could identify an active tumor more reliably, would have a major impact upon patient care and evaluation of new therapies. There is now compelling evidence that magnetic resonance spectroscopic imaging (MRSI) can provide such information as an add-on to a conventional MRI examination. We discuss data acquisition and analysis procedures which are required to perform such serial MRI-MRSI examinations and compare their results with data from histology, contrast enhanced MRI, MR cerebral blood volume imaging and FDG-PET. Applications to the serial assessment of response to therapy are illustrated by considering populations of patients being treated with brachytherapy and gamma knife radiosurgery.     

Developmental disruptions in neural connectivity in the pathophysiology of schizophrenia

Schizophrenia has been thought of as a disorder of reduced functional and structural connectivity. Recent advances in neuroimaging techniques such as functional magnetic resonance imaging, structural magnetic resonance imaging, diffusion tensor imaging, and small animal imaging have advanced our ability to investigate this hypothesis. Moreover, the power of longitudinal designs possible with these noninvasive techniques enable the study of not just how connectivity is disrupted in schizophrenia, but when this disruption emerges during development. This article reviews genetic and neurodevelopmental influences on structural and functional connectivity in human populations with or at risk for schizophrenia and in animal models of the disorder. We conclude that the weight of evidence across these diverse lines of inquiry points to a developmental disruption of neural connectivity in schizophrenia and that this disrupted connectivity likely involves susceptibility genes that affect processes involved in establishing intra- and interregional connectivity.     

Neuropsychiatric systemic lupus erythematosus: Tools for the diagnosis

Neurological involvement is considered to be a serious complication of systemic lupus erythematosus (SLE). Neuroimaging plays an important role in detecting neurological abnormalities in SLE patients. Conventional magnetic resonance imaging (cMRI) is generally the most valid neuroimaging technique for detecting alterations in the central and peripheral nervous systems. However it may occasionally fail in neuropsychiatric SLE (NPSLE). This is especially the case when the image is not very clear and may depend on the wide variety of neurological and psychiatric manifestations that define this disease.During the last twenty years, this has led to the testing of other radiological instruments, such as single photon emission computed tomography (SPECT), which is complementary to cMRI and seems to furnish additional information, and colour Doppler sonography, which provides minimal additional benefits.Our paper aims to provide a general overview of NPSLE, focusing particularly on the strengths and weaknesses of modern neuroimaging.     

Neuroimaging in Alzheimer's disease: current role in clinical practice and potential future applications

'Alzheimer's disease is the most common cause of dementia and its prevalence is expected to increase in the coming years. Therefore, accurate diagnosis is crucial for patients, clinicians and researchers. Neuroimaging techniques have provided invaluable information about Alzheimer's disease and, owing to recent advances, these methods will have an increasingly important role in research and clinical practice. The purpose of this article is to review recent neuroimaging studies of Alzheimer's disease that provide relevant information to clinical practice, including a new modality: in vivo amyloid imaging. Magnetic resonance imaging, single photon emission computed tomography and 18F-fluorodeoxyglucose-positron emission tomography are currently available for clinical use. Patients with suspected Alzheimer's disease are commonly investigated with magnetic resonance imaging because it provides detailed images of brain structure and allows the identification of supportive features for the diagnosis. Neurofunctional techniques such as single photon emission computed tomography and 18F-fluorodeoxyglucose-positron emission tomography can also be used to complement the diagnostic investigation in cases of uncertainty. Amyloid imaging is a non-invasive technique that uses positron emission tomography technology to investigate the accumulation of the β-amyloid peptide in the brain, which is a hallmark of Alzheimer's disease. This is a promising test but currently its use is restricted to very few specialized research centers in the world. Technological innovations will probably increase its availability and reliability, which are the necessary steps to achieve robust clinical applicability. Thus, in the future it is likely that amyloid imaging techniques will be used in the clinical evaluation of patients with Alzheimer's disease.     

Imaging the genetics of executive function

Recent advances in neuroimaging technologies have allowed ever more detailed studies of the human brain. The combination of neuroimaging techniques with genetics may provide a more sensitive measure of the influence of genetic variants on cognitive function than behavioural measures alone. Here we present a review of functional magnetic resonance imaging (fMRI) studies of genetic links to executive functions, focusing on sustained attention, working memory and response inhibition. In addition to studies in the normal population, we also address findings from three clinical populations: schizophrenia, ADHD and autism spectrum disorders. While the findings in the populations studied do not always converge, they all point to the usefulness of neuroimaging techniques such as fMRI as potential endophenotypes for parsing the genetic aetiology of executive function.