Presurgical functional MRI in patients with large susceptibility artifacts

磁敏感伪影较大的患者的术前功能性 MRI

基本信息

批准号：
9337439
负责人：
Jun Hua
金额：
$ 20.2万
依托单位：
HUGO W. MOSER RES INST KENNEDY KRIEGER
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-09-01 至 2019-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9337439
关键词：
Affect Air Area Brain Brain Neoplasms Brain region Calcified Clinical Clinical Protocols Clinical Research Cognitive Craniotomy Data Detection Diagnostic Procedure Dropout Echo-Planar Imaging Epilepsy Excision Functional Magnetic Resonance Imaging Goals Head Hemorrhage Hospitals Image Implant Individual Language Magnetic Resonance Imaging Magnetism Medical center Metals Methods Morphologic artifacts Neurosciences Neurosciences Research Neurosurgeon Operative Surgical Procedures Outcomes Research Pathology Patients Physiologic pulse Predisposition Preparation Protocols documentation Reproducibility Research Running Scanning Scheme Sensitivity and Specificity Signal Transduction Structure Surgically-Created Resection Cavity Techniques Temporal Lobe Time Tissues Training calcification data acquisition healthy volunteer image reconstruction improved magnetic field metallicity novel patient subsets relating to nervous system temporal measurement tool treatment strategy tumor

项目摘要

PROJECT SUMMARY/ABSTRACT Presurgical fMRI is increasingly performed in large medical centers across the US and in the world, including here at Johns Hopkins. It is commonly used in brain tumor and epilepsy patients to noninvasively locate essential cortical sensorimotor and language areas and to determine the language dominant hemisphere prior to surgery, thus helping to reduce the need for invasive diagnostic procedures such as intraoperative cortical stimulation mapping. However, a significant subpopulation of patients undergoing presurgical fMRI are affected by the well-known problems of geometric distortion and signal dropout (thus compromised sensitivity) in regions with large magnetic susceptibility effects when using the current standard BOLD fMRI method: gradient echo (GRE) echo-planar-imaging (EPI). These include several frontal and temporal regions particularly relevant for language mapping in presurgical fMRI. Furthermore, such susceptibility artifacts can also arise from cavities related to previous surgery, calcified structures, hemorrhage, and metal implants. For instance, about 25% of our presurgical fMRI referrals have undergone prior resection and are being considered for a second resection, who will suffer from susceptibility artifacts related to resection cavities and surgical metallic craniotomy hardware. Although many methods have been developed to mitigate these problems, most are region dependent or require extra data acquisition. We have recently developed a T2-prepared (T2prep) BOLD fMRI method, which showed minimal distortion and dropout and sufficient BOLD sensitivity in the entire brain even in the presence of metallic head implants, and superior BOLD sensitivity than GRE EPI in regions affected by large susceptibility artifacts. The method was initially developed at ultra-high magnetic field (7 Tesla, 7T). The goal of this R21 is to optimize and validate T2prep BOLD for presurgical fMRI in tumor patients on 3T clinical MRI scanners. Aim 1: To optimize whole-brain T2prep BOLD fMRI for typical presurgical fMRI paradigms in healthy volunteers on 3T clinical MRI scanners. The multiband techniques will be implemented for T2prep BOLD. Image quality, functional sensitivity and specificity (in regions with small or large susceptibility effects) will be compared with GRE EPI BOLD fMRI (current standard). Aim 2: To determine whether T2prep BOLD fMRI can be used as a complementary method for presurgical planning in brain tumor patients with large susceptibility artifacts at 3T. Functional results from patients using typical presurgical fMRI paradigms will be compared between T2prep BOLD and GRE EPI BOLD fMRI, and will be validated by intraoperative cortical stimulation mapping data. If the proposed research is successful, it is expected to benefit a significant subset of patients undergoing presurgical fMRI. As presurgical fMRI protocols often consist of several functional scans, T2prep BOLD fMRI can be feasibly incorporated into existing clinical protocols. Besides, we also expect the T2prep BOLD approach to be useful for other functional studies in neuroscience and clinical research as an alternative fMRI tool that can assess brain functions in previously less explored brain territories due to susceptibility related signal losses in EPI BOLD fMRI.

项目概要/摘要术前功能磁共振成像越来越多地在美国和世界各地的大型医疗中心进行，包括在约翰·霍普金斯大学。它通常用于脑肿瘤和癫痫患者，以无创地定位重要的位置皮层感觉运动和语言区域，并在手术前确定语言优势半球，从而有助于减少对侵入性诊断程序（例如术中皮质刺激）的需求映射。然而，接受术前功能磁共振成像的患者中有一个重要亚群受到以下因素的影响：在具有以下特征的区域中，众所周知的几何失真和信号丢失问题（从而损害了灵敏度）使用当前标准 BOLD fMRI 方法时的大磁化率效应：梯度回波 (GRE) 回波平面成像 (EPI)。其中包括几个与语言特别相关的额叶和颞区术前功能磁共振成像绘图。此外，这种磁化率伪影也可能由与以下相关的空腔引起：既往手术、钙化结构、出血和金属植入物。例如，我们大约 25% 术前功能磁共振成像转诊已接受过先前的切除术，正在考虑进行第二次切除术，谁将会受到与切除腔和手术金属开颅硬件相关的敏感性伪影的影响。尽管已经开发了许多方法来缓解这些问题，但大多数方法都依赖于地区或需要额外的数据采集。我们最近开发了一种 T2 准备（T2prep）BOLD fMRI 方法，该方法显示即使存在金属，整个大脑的失真和丢失也最小，并且具有足够的大胆灵敏度头部植入物，并且在受大磁化率伪影影响的区域中，BOLD 灵敏度比 GRE EPI 更高。该方法最初是在超高磁场（7特斯拉，7T）下开发的。 R21的目标是优化并在 3T 临床 MRI 扫描仪上验证 T2prep BOLD 在肿瘤患者术前 fMRI 中的应用。目标 1：优化全脑 T2prep BOLD fMRI 适用于健康志愿者的 3T 临床 MRI 典型术前 fMRI 范例扫描仪。 T2prep BOLD 将采用多频段技术。图像质量、功能灵敏度和特异性（在敏感性影响较小或较大的区域）将与 GRE EPI BOLD fMRI 进行比较（现行标准）。目标 2：确定 T2prep BOLD fMRI 是否可以用作补充方法用于 3T 磁敏感伪影较大的脑肿瘤患者的术前计划。功能结果来自使用典型术前功能磁共振成像范式的患者将在 T2prep BOLD 和 GRE EPI BOLD 之间进行比较 fMRI，并将通过术中皮质刺激映射数据进行验证。如果拟议的研究是如果成功，预计将使接受术前功能磁共振成像的大部分患者受益。作为术前 fMRI 协议通常由多次功能扫描组成，T2prep BOLD fMRI 可以切实可行地纳入现有的临床方案。此外，我们还期望 T2prep BOLD 方法对其他功能有用神经科学和临床研究作为替代功能磁共振成像工具，可以评估大脑功能由于 EPI BOLD fMRI 中与敏感性相关的信号丢失，以前较少探索大脑区域。