Unified Shim-RF Coil Technology for Improved Whole-Brain Spectroscopic MRI for Neurological Disorders

项目摘要/摘要 神经系统疾病影响着全球多达10亿人，是导致残疾和 人类的苦难。目前的标准护理成像(对比度增强MRI)非常有限，无法检测到许多 神经和神经退行性疾病。磁共振波谱成像(MRSI)具有很大的潜力 为脑肿瘤、新生儿和儿童的临床情况补充常规的临床MRI 疾病(缺氧-缺血、遗传性代谢疾病和创伤性脑损伤)、脱髓鞘疾病、 和感染性脑损伤。造影剂有不完全清除现象，且反复使用 由于脑积聚，对比增强成像最近收到了FDA的警告。MRSI并非如此 使用造影剂，对患者没有风险/风险最小。3D编码的MRSI方法提供高灵敏度 每单位时间和单位体积。手术前和放射治疗计划将从全3D中受益匪浅 信息，理想情况下具有各向同性分辨率。基于回波平面波谱成像(EPSI)的3D全脑 MRSI已经在大多数扫描仪平台上使用，并且可能是最常用的快速MRSI技术 到目前为止。3DMRSI的主要限制是磁场B0的不均匀性，这会加宽线形 并且降低了大约40%的大脑(例如，内侧颞叶，额叶下部， 额叶内侧回、脑干和小脑)。这限制了评估关键大脑区域的能力，例如 内侧颞叶(MTL)和眶前皮质(OFC)，它们在神经疾病中起着关键作用。 最近，我们引入了一个全新的概念，称为统一线圈(UNIC)，其中包括创新 分离方法，使单独的垫片和射频环路之间的距离为零毫米。RF和 垫片线圈非常接近目标器官，以获得最大的射频信噪比和垫片。物理定律蕴含着 填补局部不均匀场(如在MTL/OFC中)的唯一有效方法是放置尺寸匹配的填补 产生相反高阶场以抵消不均匀场的线圈。我们的假设是 UNIC将极大地增加脑体积覆盖率，并允许对整个大脑进行真正的新陈代谢评估 使用3D MRSI。这将使其在各种神经疾病患者的管理中得到更广泛的应用。 拟议的研究将制作第一个UNIC磁头线圈的原型(目标1)，优化垫片技术 性能和硬件复杂性(目标2)，并定量评估该技术在改善大脑方面的作用 3DMRSI的覆盖面(目标3)。这项研究的成功完成将在很大程度上解决长期存在的B0 整个大脑的不均质性问题。这样的线圈可以广泛用于使整个MRSI社区受益，方法是 先进的B0垫片技术。这将有助于促进MRSI在临床上的广泛接受。

Project Summary/Abstract Neurologic diseases affect as many as one billion people worldwide and are a major cause of disability and human suffering. Current standard of care imaging (contrast-enhanced MRI) is extremely limited to detect many neurological and neurodegenerative diseases. MR spectroscopic imaging (MRSI) has a great potential to supplement routine clinical MRI for clinical conditions including brain neoplasms, neonatal and pediatric disorders (hypoxia-ischemia, inherited metabolic diseases, and traumatic brain injury), demyelinating diseases, and infectious brain lesions. Gadolinium contrast agents have incomplete clearance, and repeated use of contrast-enhanced imaging has recently received an FDA warning due to brain accumulation. MRSI does not use contrast material and has no/minimal risk for patients. 3D encoded MRSI methods provide high sensitivity per unit time and unit volume. Presurgical and radiation treatment planning will greatly benefit from full 3D information, ideally with isotropic resolution. Echo-planar spectroscopic imaging (EPSI) based 3D whole-brain MRSI have been on most scanner platforms, and are probably the most commonly used fast MRSI techniques to date. The primary limitation of 3D MRSI has been magnetic B0 field inhomogeneity, which broadens lineshapes and diminishes spectral quality in about 40% of the brain (e.g., mesial temporal lobe, inferior frontal cortex, medial frontal gyrus, brainstem, and cerebellum). This limits the ability to evaluate critical brain regions such as mesial temporal lobe (MTL) and orbitofrontal cortex (OFC), which have pivotal roles across neurologic disorders. Recently, we introduced a radically novel concept called Unified Coil (UNIC), which includes innovative decoupling methods to bring the distance between separate shim and RF loops to zero millimeters. Both RF and shim coils are at a close proximity to the target organ for maximized RF SNR and shimming. Physical law implies that the only effective way to shim local inhomogeneous field (as in MTL/OFC) is by placing size-matched shim coils which generate opposite high-order field to counteract the inhomogeneous field. Our hypothesis is that UNIC will dramatically increase brain volume coverage and allow true metabolic evaluation of the entire brain using 3D MRSI. This will enable broader applications in patient management with various neurological disorders. The proposed study will prototype the first UNIC head coil (Aim 1), optimize the technique in shimming performance and hardware complexity (Aim 2), and assess the technique quantitatively in improving brain coverage of 3D MRSI (Aim 3). Successful completion of this study will largely resolve the longstanding B0 inhomogeneity issue in whole brain. Such coils can be widely used to benefit the entire MRSI community by advancing B0 shimming technology. It will help catalyze the widespread clinical acceptance of MRSI.