Role of fMRI in the decision-making process: epilepsy surgery for children

Functional MRI (fMRI) is increasingly being used to evaluate children and adolescents who are candidates for surgical treatment of intractable epilepsy. It has the advantage of being noninvasive and well tolerated by young people. By identifying important functional regions within the brain, including unpredictable patterns of functional reorganization, it can aid in surgical decision-making. Here we illustrate this using a number of case studies from the pediatric epilepsy surgery program at our institution. We describe how fMRI, used in conjunction with conventional investigative methods such as neuropsychological assessment, MRI, and electrophysiology, can 1) help to improve functional outcome by enabling resective surgery that spares functional cortex, 2) guide surgical intervention by revealing when reorganization of function has occurred, and 3) show when abnormal cortex is also functionally active, and hence that surgery may not be the best option. Altogether, these roles have reduced the need for invasive procedures that can be both risky and distressing for young people with epilepsy. In our experience, fMRI has significantly contributed to the decision-making process, and improved the counseling and management of young people with intractable epilepsy.     

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.     

The MR tomograph as a sound generator: fMRI tool for the investigation of the auditory cortex

An automatic fMRl protocol for the investigation of the human auditory cortex has been developed. For the activation of the auditory system, the scanner noise itself is the source of sound. Rapid switching of 6, gradients allows the generation of tones of defined frequencies and amplitude on a conventional scanner without hardware change. No additional device for sound generation or sound delivety is needed. The proposed technique allows functional MRI of the auditory cortex in a clinical routine session.     

Visual analysis of variance: A tool for quantitative assessment of fMRI data processing and analysis

Analysis of variance (ANOVA) is widely used for the study of experimental data. Here, the reach of this tool is extended to cover the preprocessing of functional magnetic resonance imaging (fMRI) data. This technique, termed visual ANOVA (VANOVA), provides both numerical and pictorial information to aid the user in understanding the effects of various parts of the data analysis. Unlike a formal ANOVA, this method does not depend on the mathematics of orthogonal projections or strictly additive decompositions. An illustrative example is presented and the application of the method to a large number of fMRI experiments is discussed. Magn Reson Med 46:1202–1208, 2001. © 2001 Wiley‐Liss, Inc.     

中医药临床疗效研究中多模态fMRI的应用

目的：系统评价中医药临床疗效研究中fMRI的应用现状、问题及前景。方法：系统检索国内外多个中文及英文数据库,系统评价BOLD-fMRI、DTI及¹H-MRS在中医药临床疗效研究中的应用。结果：纳入研究的47篇文献中,27篇使用BOLD模态,13篇使用MRS模态,4篇使用DTI模态,3篇同时使用2种模态。目前研究多集中在局部脑区功能和环路异常2个层面,未发现脑网络研究;理论驱动和数据驱动的数据处理方式均得到运用,但ROI的选择存在较高的异质性,限制了DTI和MRS研究结果的可比性。结论：中医药临床疗效的fMRI研究呈爆发态势,但在参数设置方面需更加规范,在多模态融合、节点-环路-网络的靶点选择及数据分析方式等方面应增加研究的广度和深度。     

Somatomotor fMRI in the pre-surgical evaluation of a case of focal epilepsy.

A child with intractable partial epilepsy who was found to have a focal lesion in the motor cortex underwent detailed pre-surgical and intraoperative investigations which enabled curative surgery without morbidity by minimizing a targeted resection. The pre-surgical assessment included mapping motor cortical function with functional magnetic resonance imaging (fMRI). This was subsequently correlated with the results of pre-surgical and intraoperative invasive corticography.     

Combining epidemiology and biomechanics in sports injury prevention research: a new approach for selecting suitable controls

Several important methodological issues need to be considered when designing sports injury case-control studies. Major design goals for case-control studies include the accounting for prior injury risk exposure, and optimal definitions of both cases and suitable controls are needed to ensure this. This article reviews methodological aspects of published sports injury case-control studies, particularly with regard to the selection of controls. It argues for a new approach towards selecting controls for case-control studies that draws on an interface between epidemiological and biomechanical concepts. A review was conducted to identify sport injury case-control studies published in the peer-review literature during 1985-2008. Overall, 32 articles were identified, of which the majority related to upper or lower extremity injuries. Matching considerations were used for control selection in 16 studies. Specific mention of application of biomechanical principles in the selection of appropriate controls was absent from all studies, including those purporting to evaluate the benefits of personal protective equipment to protect against impact injury. This is a problem because it could lead to biased conclusions, as cases and controls are not fully comparable in terms of similar biomechanical impact profiles relating to the injury incident, such as site of the impact on the body. The strength of the conclusions drawn from case-control studies, and the extent to which results can be generalized, is directly influenced by the definition and recruitment of cases and appropriate controls. Future studies should consider the interface between epidemiological and biomechanical concepts when choosing appropriate controls to ensure that proper adjustment of prior exposure to injury risk is made. To provide necessary guidance for the optimal selection of controls in case-control studies of interventions to prevent sports-related impact injury, this review outlines a new case-control selection strategy that reflects the importance of biomechanical considerations, which ensures that controls are selected based on the presence of the same global injury mechanism as the cases. To summarize, the general biomechanical principles that should apply to the selection of controls in future case-control studies are as follows: (i) each control must have been exposed to the same global injury mechanism as the case, (e.g. head impact, fall onto outstretched arm); and (ii) intrinsic (individual) factors (e.g. age, sex, skill level) that might modify the person's response to the relevant biomechanical loads are adjusted when either selecting the controls or are in the analysis phase. The same considerations for control selection apply to other study designs such as matched cohort studies or case-crossover studies.     

Clinical practice of language fMRI in epilepsy centers: a European survey and conclusions by the ESNR Epilepsy Working Group

To assess current clinical practices throughout Europe with respect to acquisition, implementation, evaluation, and interpretation of language functional MRI (fMRI) in epilepsy patients. An online survey was emailed to all European Society of Neuroradiology members (n = 1662), known associates (n = 6400), and 64 members of European Epilepsy network. The questionnaire featured 40 individual items on demographic data, clinical practice and indications, fMRI paradigms, radiological workflow, data post-processing protocol, and reporting. A total of 49 non-duplicate entries from European centers were received from 20 countries. Of these, 73.5% were board-certified neuroradiologists and 69.4% had an in-house epilepsy surgery program. Seventy-one percent of centers performed fewer than five scans per month for epilepsy. The most frequently used paradigms were phonemic verbal fluency (47.7%) and auditory comprehension (55.6%), but variants of 13 paradigms were described. Most centers assessed the fMRI task performance (75.5%), ensured cognitive-task adjustment (77.6%), trained the patient before scanning (85.7%), and assessed handedness (77.6%), but only 28.6% had special paradigms for patients with cognitive impairments. fMRI was post-processed mainly by neuroradiologists (42.1%), using open-source software (55.0%). Reporting was done primarily by neuroradiologists (74.2%). Interpretation was done mainly by visual inspection (65.3%). Most specialists (81.6%) were able to determine the hemisphere dominance for language in more than 75% of exams, attributing failure to the patient not performing the task correctly. This survey shows that language fMRI is firmly embedded in the preoperative management of epilepsy patients. The wide variety of paradigms and the use of non-CE-marked software underline the need for establishing reference standards.     

针刺治疗阿茨海默病的fMRI研究

阿茨海默病（Alzheimer’s alzheimer’s disease,AD）是一种严重影响老年健康的疾病,在老龄化社会中尤其显著,但是迄今为止,尚未有对AD有效的治疗方法。针刺是一种重要的中医疗法,已经在AD治疗中得到初步的应用,本文对针刺治疗AD的机理以及fMRI在治疗中的应用价值做初步综述。     

Comparative analysis of MR imaging,Ictal SPECT and EEG in temporal lobe epilepsy: a prospective IAEA multi-center study

Background and purpose MR imaging, ictal single-photon emission CT (SPECT) and ictal EEG play important roles in the presurgical localization of epileptic foci. This multi-center study was established to investigate whether the complementary role of perfusion SPECT, MRI and EEG for presurgical localization of temporal lobe epilepsy could be confirmed in a prospective setting involving centers from India, Thailand, Italy and Argentina. Methods We studied 74 patients who underwent interictal and ictal EEG, interictal and ictal SPECT and MRI before surgery of the temporal lobe. In all but three patients, histology was reported. The clinical outcome was assessed using Engel’s classification. Sensitivity values of all imaging modalities were calculated, and the add-on value of SPECT was assessed. Results Outcome (Engel’s classification) in 74 patients was class I, 89%; class II, 7%; class III, 3%; and IV, 1%. Regarding the localization of seizure origin, sensitivity was 84% for ictal SPECT, 70% for ictal EEG, 86% for MRI, 55% for interictal SPECT and 40% for interictal EEG. Add-on value of ictal SPECT was shown by its ability to correctly localize 17/22 (77%) of the seizure foci missed by ictal EEG and 8/10 (80%) of the seizure foci not detected by MRI. Conclusions This prospective multi-center trial, involving centers from different parts of the world, confirms that ictal perfusion SPECT is an effective diagnostic modality for correctly identifying seizure origin in temporal lobe epilepsy, providing complementary information to ictal EEG and MRI. Part of this work was presented at the 2005 SNM meeting in Toronto, Canada.     

MRIgHIFU: a tool for image-guided therapeutics

High-intensity focused ultrasound (HIFU) provides focal delivery of mechanical energy deep into the body. This energy can be used to elevate the tissue temperature to such a degree that ablation is achieved. The elevated temperature can also be used to release drugs from temperature-sensitive carriers or activate therapeutic molecules using mechanical or thermal energy. Lower dose exposures modify the vasculature to allow large molecules to diffuse from blood in the surrounding tissue for local drug delivery. The energy delivery can be targeted and monitored using magnetic resonance imaging (MRI). The online image guidance and monitoring provides treatment delivery that is customized to each patient such that optimal, effective treatment can be achieved. This ability to localize and customize treatment delivery may further enhance the future potential of targeted drugs that are personalized for each patient. This review examines the rapid development of MRI-guided HIFU (MRIgHIFU) methods over the past few years and discuss their future potential.     

Marketing: a tool for survival.

Surviving the changes in radiology, especially reimbursement changes, will call for new management techniques. One of these new approaches is marketing: it gives radiology managers the tools they need to become more aware of customers' needs and to direct their organizations to meet those needs. This article will attempt to dispel some myths about marketing, to describe the role of marketing in the radiology setting, and to walk through a step-by-step program for involvement of the radiology department in marketing.     

Magnetic resonance imaging as a research tool for biomechanical studies of the wrist

The field of biomechanics has welcomed magnetic resonance imaging (MRI) as a research tool to provide quantified anatomy of various body parts in vivo. The ability to view, reconstruct, and analyze images of an intact system under varying conditions has improved our knowledge of functional anatomy. This article forms a review of MRI use in biomechanics research, with examples from several areas and an emphasis on the distal upper extremity. Biomechanical parameters such as muscle fascicle directions of pull, moment arms in three dimensions, muscle cross-sectional areas, and detailed muscle geometry data are prevalent because of advances in imaging technology. This has resulted in improved anatomic realism in biomechanical models. Wrist biomechanics research has benefited greatly using MRI. The unique anatomy of the carpal tunnel, and the concerns regarding carpal tunnel syndrome, have prompted numerous studies examining the contents of the carpal tunnel, its shape, and its volume. These studies are presented, as is an analysis of the finger flexor tendons as they pass through the carpal tunnel. These imaging-based studies all examine the aspects of the potential mechanisms for median nerve compression at the wrist. MRI is a tremendously valuable tool in biomechanics research, especially in the search for the mechanisms of carpal tunnel syndrome and wrist function, providing both visual representation and quantitative evaluation of anatomic phenomena.     

Isotropic submillimeter fMRI in the human brain at 7 T: Combining reduced field-of-view imaging and partially parallel acquisitions

Echo‐planar imaging is the most widely used imaging sequence for functional magnetic resonance imaging (fMRI) due to its fast acquisition. However, it is prone to local distortions, image blurring, and signal voids. As these effects scale with echo train length and field strength, it is essential for high‐resolution echo‐planar imaging at ultrahigh field to address these problems. Partially parallel acquisition methods can be used to improve the image quality of echo‐planar imaging. However, partially parallel acquisition can be affected by aliasing artifacts and noise enhancement. Another way to shorten the echo train length is to reduce the field‐of‐view (FOV) while maintaining the same spatial resolution. However, to achieve significant acceleration, the resulting FOV becomes very small. Another problem occurs when FOV selection is incomplete such that there is remaining signal aliased from the region outside the reduced FOV. In this article, a novel approach, a combination of reduced FOV imaging with partially parallel acquisition, is presented. This approach can address the problems described above of each individual method, enabling high‐quality single‐shot echo‐planar imaging acquisition, with submillimeter isotropic resolution and good signal‐to‐noise ratio, for fMRI at ultrahigh field strength. This is demonstrated in fMRI of human brain at 7T with an isotropic resolution of 650 μm. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.     

重组肿瘤相关抗原蛋白与肿瘤治疗性DNA疫苗静电耦合成为复合纳米颗粒的初步研究

目的:验证原核表达的重组肿瘤相关抗原蛋白SUR-IM与肿瘤治疗性DNA疫苗pVAX1-2PFcGB能够通过静电耦合形成复合纳米颗粒.方法:通过蛋白-DNA琼脂糖凝胶电泳阻滞实验、DNaseⅠ消化核酸的保护实验及原子力显微镜观察验证二者是否结合;此外,通过体外瞬时转染293T细胞研究蛋白质所结合的质粒是否能够在体外顺利表达.结果:证实二者确实能够通过静电耦合形成纳米级的颗粒,结合后蛋白质对DNA具有一定的保护作用,并且蛋白不会影响与之结合的质粒在细胞中的高效表达.结论:该复合纳米颗粒将蛋白质和核酸组分有机结合在一起,使肿瘤抗原、免疫佐剂及DNA肿瘤疫苗协同发挥作用,为日后进行抗肿瘤功能研究奠定了重要基础.