Pseudo Random Amplitude Modulation of Arterial Spin Labeling

动脉自旋标记的伪随机幅度调制

• 批准号: 8598872
• 负责人: Truman R Brown
• 金额: $ 14.31万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8598872
• 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

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（由申请人提供）：动脉自旋标记（ASL）在测量大脑血流（CBF）和区域脑灌注方面具有许多优势。这种测量对于中风，缺血，脑肿瘤和痴呆症的研究，诊断和治疗至关重要。 ASL是非侵入性，便宜的，并且会产生高分辨率图像，这些图像与其他解剖学和功能性磁共振成像（MRI）扫描很容易被比较。 ASL方法涉及通过将动脉旋转倒在成像体积的平面上来标记动脉旋转。 CBF计算的主要因素是标记质子从成像平面传递到标记平面的传输时间。大多数标准的ASL序列都遭受了无法直接测量运输时间的限制。取而代之的是，他们依靠一种解决旅行时间效果的方法，该方法引入了多种混杂和限制来源 信噪比，尤其是白质。此外，标准的ASL测量值无法确定检测到的变化是否是对流动变化的真正反映，还是已知参与神经激活和中风的过境时间变化的结果。在 该建议，我们描述了一种新型的动脉自旋标记方法，能够直接测量过境时间。我们的方法提供了标准ASL的优势，同时消除了其一些局限性。这是通过根据伪随机序列标记动脉旋转来实现的。用于伪随机振幅调制的序列的数学特性，或定价，可以恢复成像组织中存在的所有运输时间，作为单个综合采集的一部分。这种方法的实施应提供对宏观和微观水平上脑血流细节的新见解。详细的具体目的是：特定目标1A：在西门子3T三重奏扫描仪上实施伪随机动脉调制（PRAM）方案。特定目标2：使用幻像中的标准自旋标记和ASL技术验证在SA 1中开发的婴儿车序列。特定目的3：通过将婴儿车结果与标准PASL序列获得的验证结果进行比较，将验证研究扩展到接受视觉刺激的人类志愿者。