磁共振神经成像在周围神经疾病的临床应用

磁共振成像技术的进展已经使周围神经疾病的诊断从传统的临床和电生理检查向解剖学研究转化。磁共振神经成像能够获取周围神经纵切面和横切面的影像,来直接观察神经内外的病灶。磁共振神经成像作为一种敏感的非侵入性技术,可用于诊断周围神经的神经压迫症、炎症、创伤、康复和系统性神经疾病。这就要求神经科医生与放射科医生一样,也要熟识该领域各种新技术的影像表现。本文将对磁共振神经成像在周围神经疾病的临床应用以及目前存在的问题和磁共振实验研究作一综述,包括相应的技术介绍。     

基于磁共振技术的血管性认知障碍研究进展

血管性认知障碍目前尚缺乏统一的影像诊断标准,近年来磁共振技术的发展提供了有助 于血管性认知障碍早期诊断的神经影像学标志物。本文从弥散张量成像、磁共振波谱、磁共振磁 敏感加权成像和功能磁共振成像多种磁共振模态对血管性认知障碍的影像特点进行综述。将多种 模态的神经影像学检查方法联合运用有助于提高血管性认知障碍临床诊断的准确率,为进一步的 治疗提供帮助。     

高分辨磁共振神经病学应用进展

高分辨磁共振的进展主要集中在成像技术的更新,研究和临床实践领域的扩展以及新的影像症候的提出。近年来,高分辨成像技术血管壁影像的分辨率和清晰度不断提高,并逐渐过渡到多参数影像模式对比的阶段;而随着神经内科、外科和影像医生越来越认识到高分辨磁共振的价值,在临床中不断地探索使用,使它的适用范围也扩大,从动脉粥样硬化扩展到夹层、动脉炎、Moyamoya病等。本文分别对高分辨磁共振技术的成像方法和应用范围进行了综述。     

磁共振功能成像技术在帕金森病诊断及鉴别诊断中应用进展

帕金森病(PD)的早期诊断一直是困扰神经内科医生,尤其是PD研究者的难题。多年来,国内外学者一直致力于寻找PD早期诊断的标志物。近年来,随着磁共振技术,特别是磁共振功能成像技术的广泛应用及不断发展,为我们研究PD脑内形态变化、生化改变及协助临床诊断提供了有效的工具。目前,国内外学者运用各种磁共振功能成像技术对PD进行了一系列研究,取得了一定的成果,该文就磁共振功能成像技术在PD诊断及鉴别诊断中应用进展作一综述。     

帕金森病认知损害的神经影像学研究进展

帕金森病(PD)是一种常见的中枢神经系统变性疾病,认知损害是PD常见的非运动症状之一,其机制目前尚不完全清楚。神经影像学技术可以显示疾病特异性的结构和功能特征,是研究PD认知损害发生发展机制的强大工具。文中将从神经影像技术中的磁共振成像和正电子发射计算机断层扫描两个方面,对近年来PD认知损害的神经影像学研究进展予以综述。     

磁共振成像在多发性硬化的临床应用

多发性硬化(multiple sclerosis,MS)是常见的中枢神经系统炎性脱髓鞘疾病,具有时间和空间多发性.磁共振成像(magnetic resonance imaging,MRI)已在临床上广泛应用,尤其在MS临床诊断、机制研究以及疗效监测方面发挥了其他影像技术无法替代的作用.     

中国脑血管病影像应用指南的更新

为了将新的影像技术及时地应用于临床,中华医学会神经病学分会及其脑血管病学组更新了中国脑血管病影像应用指南。指南主要新增加了平扫CT预测早期血肿扩大、一站式多模态CT在急诊脑血管病诊疗中的应用、磁共振成像在血管源性白质损伤诊断和鉴别诊断中的应用、血管壁磁共振成像技术临床应用价值、磁敏感加权成像在各种出血以及血栓的早期诊断中的应用等。指南还对具有临床应用前景的一些技术(如动脉自旋标记)进行了介绍。希望能与时俱进、不断更新,更好地为临床服务。     

神经肌肉病临床生物学资源数据库建立及应用

神经肌肉病是一组以周围神经、神经-肌肉接头和肌肉受累为主的疾病。除传统的临床诊断、血清学、神经电生理学和病理学等诊断方法外,不断发展的临床、影像学、细胞和分子生物学等多层面检测技术广泛应用于此类疾病的诊断。在神经肌肉病的研究中,实现临床和生物学资源管理的标准化和系统化十分必要。本文针对神经肌肉病临床生物学资源数据库的建立、管理及应用进行综述,以期有助于推动此类疾病的研究。     

颅内血管病的高分辨磁共振成像——重新认识脑血管病的开始

<正>一种医用技术是否具有生命力,主要看它是否能够促进临床的诊断或者治疗,改变对疾病的认识。技术的出现不是为了产生几篇论文,如果不能应用到实践,它最终不会被接受。在2006年,法国的放射科医生Klein用1.5 T磁共振(magnetic resonance imaging,MRI)完成大脑中动脉的血管壁成像之后,高分辨磁共振(high-resolution magnetic resonance imaging,HRMRI)的颅内血管成像技术引起广泛关注~([1])。在2009年,加拿大的Swartz和中国北京协和医院的李明利医生先后用3.0 T磁共振进行了颅内血管成像,获得更高的成像质量,使其具备了观察者间和观察者     

多模态影像融合技术在神经外科的应用及进展

随着医学影像学诊断技术的进步,为了综合解剖结构影像(CT、MRI、B超等)和功能影像(功能磁共振成像、扩散张量成像、正电子发射体层摄影术等)的优势,多模态影像融合技术应运而生,并且有了较大发展,使神经外科的理念有了极大转变。近年来,以影像融合为基础的功能神经导航和术中磁共振成像等技术更是给神经外科带来革命性的变化,使神经外科尤其是脑实质内病变的手术方式取得显著进步。利用多模态功能神经导航技术可以标记并在术中保护重要脑功能结构,以最大化地提高患者术后生存质量,有效延长患者术后生存时间,对改善重要脑功能区的手术疗效、减少术后并发症具有重要临床意义。     

MR-Neurographie zur Läsionslokalisation im peripheren Nervensystem

Peripheral neuropathies are frequent disorders which are often challenging in the diagnostic work-up. Diagnostic difficulties first and foremost arise with regard to lesion localization and the precise definition of spatial lesion patterns. Magnetic resonance (MR) neurography as a diagnostic imaging tool directly visualizes nerve lesions thereby facilitating lesion localization not only in traumatic nerve lesions but also in the large and heterogeneous group of intrinsic, spontaneously occurring non-focal neuropathies. The major diagnostic sign for lesion detection and localization is the T2 lesion which can be evaluated with high spatial resolution at the anatomical level of nerve fascicles. Lesion detection at the fascicular level by MR neurography advances the diagnostic work-up in the peripheral nervous system (PNS), because fascicular and partial nerve lesions of spontaneously occurring intrinsic neuropathies and polyneuropathies present a classical diagnostic pitfall for traditional localization by means of physical findings and electrophysiology. With the appropriate techniques and strategies MR neurography can now cover large anatomical areas of the PNS in a single examination session.     

MR neurography: diagnostic utility in the surgical treatment of peripheral nerve disorders

Advances in MR imaging have improved the visualization of normal and pathologic peripheral nerve structures in various clinical settings. Peripheral nerve imaging has the potential to dramatically change the diagnosis and treatment of peripheral nerve pathology and lead to an improved understanding of peripheral nerve pathophysiology. Currently, MR imaging serves as a problem-solving tool when additional anatomic information is needed to clarify ambiguous electrodiagnostic and clinical examinations. The next major advance in MR imaging of peripheral nerves will likely be the transition from anatomic to physiologic imaging with higher resolution as better phased-array surface coils and higher-field-strength magnets become available. Finally, MR neurography should remain complementary to the clinical examination and electrodiagnostic studies in the evaluation of peripheral nerve disorders.     

MR neurography for the evaluation of CIDP

Introduction: To visualize peripheral nerves in patients with chronic inflammatory demyelinating polyneuropathy (CIDP), we used MR imaging. We also quantified the volumes of the brachial and lumbar plexus and their nerve roots. Methods: Thirteen patients with CIDP and 12 healthy volunteers were enrolled. Whole‐body MR neurography based on diffusion‐weighted whole‐body imaging with background body signal suppression (DWIBS) was performed. Peripheral nerve volumes were calculated from serial axial MR images. Results: The peripheral nervous system was visualized with 3‐dimensional reconstruction. Volumes ranged from 8.7 to 49.5 cm³/m² in the brachial plexus and nerve roots and from 10.2 to 53.5 cm³/m² in the lumbar plexus and nerve roots. Patients with CIDP had significantly larger volumes than controls (P < 0.05), and volume was positively correlated with disease duration. Conclusions: MR neurography and the measurement of peripheral nerve volume are useful for diagnosing and assessing CIDP. Muscle Nerve 55 : 483–489, 2017     

MR neurography and muscle MR imaging for image diagnosis of disorders affecting the peripheral nerves and musculature

Recent advances in the technology of MR imaging are beginning to transform the fundamental methodology of diagnostic evaluations in neuromuscular disorders. When properly implemented, MR neurography is capable of providing high-quality information about nerve compression, nerve inflammation, nerve trauma, systemic neuropathies, nerve tumors, and recovery of nerve from pathologic states. Muscle MR imaging can identify denervation on a precise anatomic basis, document the progression of various conditions causing myopathy and myositis; and even provide insight into abnormal patterns of muscle activation. There is an essential role for the neurologist as well as for the specialist radiologist that requires a high level of familiarity of the various new types of image findings in this steadily advancing field.     

Technology insight: visualizing peripheral nerve injury using MRI

Currently, the evaluation of peripheral nerve disorders depends on clinical examination, supplemented by electrophysiological studies. These approaches provide general information on the distribution and classification of nerve lesions-for example, axonal versus demyelinative-but nerve biopsies are still required to obtain morphological and pathophysiological details. In this article, we review recent progress in the imaging of peripheral nerve injury by magnetic resonance (MR) neurography. Axonal nerve injury leads to Wallerian degeneration, resulting in a hyperintense nerve signal on T2-weighted MR images of the distal nerve segment. This signal is lost following successful regeneration. Concomitant denervation-induced signal alterations in muscles can further help us to determine whether nerve trunks or roots are affected. These signal changes are caused by various combinations of nonspecific tissue alterations, however, and are not related to particular pathoanatomical findings, such as inflammation, demyelination or axonal injury. New experimental MR contrast agents, such as gadofluorine M and superparamagnetic iron oxide particles, allow visualization of the dynamics of peripheral nerve injury and repair. Further clinical development of these MR contrast agents should allow these functional aspects of nerve injury and repair to be assessed in humans, thereby aiding the differential diagnosis of peripheral nerve disorders.     

Magnetic resonance neurography in extraspinal sciatica

BACKGROUND: Sciatica without evidence of lumbosacral root compression is often attributed to piriformis syndrome. However, specific diagnostic tools have not been available to demonstrate sciatic nerve entrapment by the piriformis muscle. OBJECTIVE: To evaluate the use of magnetic resonance (MR) neurography in identifying abnormalities of the sciatic nerve in patients with unexplained sciatica. DESIGN: Case series from a retrospective medical record review. PATIENTS: Fourteen patients with sciatic distribution pain and normal results on MR imaging for lumbosacral radiculopathy were referred for MR neurography of the lumbosacral plexus and sciatic nerves. RESULTS: In 12 patients, MR neurography demonstrated increased fluid-attenuated inversion recovery signal in the ipsilateral sciatic nerve. In most patients, this abnormal signal was seen at the sciatic notch, at or just inferior to the level of the piriformis muscle. To date, 4 patients have undergone surgical decompression, with excellent relief of symptoms in 3 of them. CONCLUSION: Magnetic resonance neurography often identifies an abnormal increased signal in the proximal sciatic nerve in patients with extraspinal sciatica and allows more accurate diagnosis of sciatic nerve entrapment in suspected cases.     

High-resolution 3T MR neurography of radial neuropathy

The radial nerve is a continuation of the posterior cord of the brachial plexus and one of the major nerves that provide motor and sensory innervations to the forearm. MR imaging evaluation of the radial nerve pathology has been described in scattered case reports. Current high-field MR scanners enable high resolution and high contrast imaging of the peripheral nerves. This article reviews the 3 Tesla magnetic resonance neurography imaging of radial nerve anatomy and various pathologies affecting it with relevant case examples.     

Diagnosis of carpal tunnel syndrome: electrodiagnostic and MR imaging evaluation

In clinically classic carpal tunnel syndrome (CTS) without symptoms or signs to suggest other disorders that can mimic CTS, it remains somewhat controversial as to whether performing nerve conduction studies is necessary or cost-effective. MR imaging reliably depicts normal carpal tunnel anatomy. It can also identify pathologic nerve compression and mass lesions, such as ganglion cysts, that compress nerves. Currently, MR imaging is most commonly used to image patients with ambiguous electrodiagnostic studies and clinical examinations. MR diffusion-weighted imaging of peripheral nerves might prove to be the most sensitive imaging sequence for the detection of early nerve dysfunction. Electrodiagnostic studies are likely to remain the pivotal diagnostic examination in patients with suspected CTS for the foreseeable future. With advances in both software and hardware, however, high-resolution MR imaging of peripheral nerves will become faster, cheaper, and likely more accurate, possibly paving the way for an expanded role in the diagnosis of this common syndrome.