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Diagnostic Imaging of Cerebral Blood Flow with MRI

MRI 脑血流诊断成像

基本信息

批准号：
6644750
负责人：
DAVID Charles ALSOP
金额：
$ 30.45万
依托单位：
BETH ISRAEL DEACONESS MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-09-30 至 2005-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6644750
关键词：
Alzheimer's disease bioimaging /biomedical imaging blood flow measurement brain circulation brain disorder diagnosis brain imaging /visualization /scanning cerebrospinal fluid clinical research diagnosis design /evaluation diagnostic tests human subject magnetic resonance imaging method development questionnaires

项目摘要

Imaging of Cerebral Blood Flow (CBF) is a powerful technique for the diagnostic evaluation of patients with dementia, stroke and epilepsy. A technique known as Arterial Spin Labeling MRI has demonstrated the ability to provide high quality images of CBF without radioactivity or injection. The advancement of this technique has been limited, however, by the destructive effects of patient motion, the poor image quality of the fast, echoplanar imaging technique used to combat these motion effects, and the inability to acquire images from the entire brain in a reasonable exam period. The applicants propose to overcome these limitations by refining a novel background suppression approach. Multiple inversion pulses will be used to reduce the intensity of uninteresting signals prior to image acquisition. This approach can reduce motion-related errors by a factor of 100 while preserving the CBF signal. Because of the dramatic reduction in motion-related errors, a superior, 3D fast spin echo imaging approach can be employed to provide CBF images from the whole brain in under 6 minutes with twice the sensitivity of earlier approaches. We propose to realize this potential of this approach by: 1. Optimizing the design of the RF pulses used for background suppression to minimize CBF signal loss and systematic errors near the top and bottom of the brain. 2. Using a nonlinear minimization strategy to optimize the timing of the inversions so as to achieve ideal background suppression 3. Developing a strategy for T1 quantification of brain tissue that will be compatible with the 3D fast spin echo sequence and which will be insensitive to the presence of cerebrospinal fluid(CSF). TI measurement is required for CBF measurement but can be contaminated by small amounts of CSF in the voxel. 4. Measuring the efficiency of the background suppressed sequences. Efficiency will be measured as a function of labeling plane location to guide the choice of parameters for subsequent applications. 5. Measuring the test-retest reliability of the optimized CBF imaging method in normal controls and patients with dementia and comparing it to unsuppressed methods. This information is needed for the design and interpretation of diagnostic tests, pharmaceutical evaluations and other studies employing CBF MRI. These developments will make reliable CBF imaging by Arterial Spin Labeling a widely applicable technique for diagnostic imaging.

脑血流成像(CBF)是诊断痴呆、中风和癫痫患者的一项强有力的技术。一种名为动脉自旋标记MRI的技术已经证明，在没有放射性或注射的情况下，能够提供高质量的CBF图像。然而，由于患者运动的破坏性影响，用于对抗这些运动效应的快速回波平面成像技术的图像质量较差，以及无法在合理的检查周期内从整个大脑获取图像，这一技术的进步受到了限制。申请人建议通过改进一种新的背景抑制方法来克服这些限制。在图像采集之前，将使用多个反转脉冲来降低不感兴趣的信号的强度。这种方法可以在保留CBF信号的同时将与运动相关的误差减少到原来的100倍。由于运动相关错误的显著减少，一种优越的3D快速自旋回波成像方法可以在不到6分钟的时间内提供来自整个大脑的CBF图像，其灵敏度是以前方法的两倍。我们建议通过以下方法来实现这种方法的潜力：1.优化用于背景抑制的RF脉冲的设计，以最小化CBF信号损失和大脑顶部和底部附近的系统误差。2.使用非线性最小化策略来优化反转的时间，以实现理想的背景抑制3.开发一种将与3D快速自旋回波序列兼容并且对脑脊液(CSF)的存在不敏感的脑组织T1量化策略测量脑血流量需要测量脑脊液，但会受到体素中少量脑脊液的污染。4.测量背景抑制序列的效率。效率将作为标记平面位置的函数来测量，以指导后续应用的参数选择。5.测量优化的脑血流显像方法在正常对照组和痴呆患者中的重测信度，并与未抑制的方法进行比较。这些信息是设计和解释诊断测试、药物评估和其他使用CBF MRI的研究所必需的。这些进展将使动脉自旋标记的可靠的CBF成像成为一种广泛应用的诊断成像技术。