Pseudo Random Amplitude Modulation of Arterial Spin Labeling

动脉自旋标记的伪随机幅度调制

基本信息

批准号：
8445945
负责人：
Truman R Brown
金额：
$ 22.13万
依托单位：
MEDICAL UNIVERSITY OF SOUTH CAROLINA
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-01-01 至 2014-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8445945
关键词：
Arteries Blood Blood flow Brain Brain Neoplasms Brain region Cerebrovascular Circulation Clinical Complex Dementia Development Diagnosis Disease Frequencies Functional Magnetic Resonance Imaging Goals Head Human Volunteers Image Imaging Techniques Ischemia Label Magnetic Resonance Imaging Measurement Measures Methodology Methods Microscopic Modeling Names Neck Noise Pathology Perfusion Persons Photic Stimulation Physiologic pulse Physiological Plexiglas Plexiglass Principal Investigator Property Protocols documentation Protons Pump Radioactive Tracers Recovery Relaxation Reproducibility Research Resolution Running Scanning Scheme Signal Transduction Slice Solutions Sorting - Cell Movement Source Spin Labels Stroke Techniques Testing Time Tissues To specify Travel Uncertainty Visual Cortex Water Work base case control cerebral artery cost data acquisition design improved insight meetings novel programs public health relevance relating to nervous system research study response tumor validation studies verification and validation volunteer white matter

项目摘要

DESCRIPTION (provided by applicant): Arterial spin labeling (ASL) has many advantages for the measurement of cerebral blood flow (CBF) and regional brain perfusion. Such measurements are significant for research and diagnosis and treatment of stroke, ischemia, brain tumors, and dementia. ASL is non-invasive, inexpensive, and produces high-resolution images that are easily compared with other anatomical and functional magnetic resonance imaging (MRI) scans acquired as part of the same session. The ASL method involves labeling inflowing arterial spins by inverting them at a plane proximal to the imaging volume. A major factor in the calculation of CBF is the transit time for the labeled protons to pass from the imaging plane and into the labeling plane. Most standard ASL sequences suffer from the limitation that they cannot measure transit times directly. Instead, they rely on a method of factoring out the effect of travel times that is introduces multiple sources of confound and limits signal-to-noise ratio, especially in white matter. Furthermore, standard ASL measurements are unable to determine whether the changes detected are truly reflections of changes in flow or the result of the alterations in transit times known to be involved in neural activation and stroke. In this proposal, we describe a novel method of arterial spin labeling that is able to directly measure transit times. Our method offers the advantages of standard ASL while removing some of its limitations. This is made possible by labeling the arterial spins according to a pseudo random sequence. The mathematical properties of the sequence used for pseudo random amplitude modulation, or PRAM, allow recovery of all the transit times present in the imaged tissue as part of a single integrated acquisition. Implementation of this method should provide novel insights into the details of cerebral blood flow at both the macroscopic and microscopic levels. Detailed specific aims are: Specific Aim 1a: Implement the pseudo random arterial modulation (PRAM) scheme on a Siemens 3T Trio scanner. Specific Aim 2: Validate the PRAM sequence developed in SA 1 using standard spin tagging and ASL techniques in phantoms. Specific Aim 3: Extend the validation studies to human volunteers undergoing visual stimulation by comparing the PRAM results to those acquired by standard PASL sequences.

描述（申请人提供）：动脉自旋标记（ASL）对于测量脑血流量（CBF）和局部脑灌注有许多优点。这些测量对于中风、缺血、脑肿瘤和痴呆症的研究、诊断和治疗具有重要意义。 ASL 是非侵入性的、廉价的，并且可以生成高分辨率图像，可以轻松地与同一会话中获取的其他解剖和功能磁共振成像 (MRI) 扫描进行比较。 ASL 方法涉及通过在靠近成像体积的平面上反转动脉自旋来标记流入的动脉自旋。 CBF 计算中的一个主要因素是标记质子从成像平面进入标记平面的渡越时间。大多数标准 ASL 序列都受到无法直接测量传输时间的限制。相反，他们依赖于一种排除旅行时间影响的方法，这种方法会引入多种混淆和限制来源信噪比，尤其是在白质中。此外，标准 ASL 测量无法确定检测到的变化是否真正反映了流量变化或已知与神经激活和中风有关的传输时间变化的结果。在在这个提案中，我们描述了一种新的动脉自旋标记方法，能够直接测量通过时间。我们的方法提供了标准 ASL 的优点，同时消除了它的一些限制。这是通过根据伪随机序列标记动脉自旋来实现的。用于伪随机幅度调制（PRAM）的序列的数学特性允许恢复成像组织中存在的所有传输时间，作为单个集成采集的一部分。这种方法的实施应该为宏观和微观水平上的脑血流细节提供新的见解。详细的具体目标是：具体目标 1a：在西门子 3T Trio 扫描仪上实施伪随机动脉调制 (PRAM) 方案。具体目标 2：在模型中使用标准自旋标记和 ASL 技术验证 SA 1 中开发的 PRAM 序列。具体目标 3：通过将 PRAM 结果与标准 PASL 序列获得的结果进行比较，将验证研究扩展到接受视觉刺激的人类志愿者。