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Determining properties of subvoxel objects from MRI images

从 MRI 图像中确定亚体素对象的属性

基本信息

批准号：
8121506
负责人：
Yu-chung Norman Cheng
金额：
$ 21.89万
依托单位：
WAYNE STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-07-01 至 2013-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8121506
关键词：
Accounting Affect Aging Algorithms Alzheimer&apos s Disease Amyloid Animals Biochemical Biological Biological Markers Brain Calcified Calcium Cells Clinical Research Complex Contrast Media Data Dementia Deposition Diagnosis Disease Disease Progression Electromagnetics Goals Human Human body Image Indium Individual Iron Knowledge Label Lead Magnetic Resonance Imaging Magnetism Mathematics Measurement Measures Medicine Methods Modeling Monitor Multiple Sclerosis Noise Phase Physics Predisposition Prevalence Procedures Property Public Health Research Resolution Senile Plaques Signal Transduction Solutions Source Spottings Staging Stroke Study Section Tissues Traumatic Brain Injury Uncertainty Veins Water Work base cranium design electromagnetism human data improved in vivo interest magnetic field molecular imaging nanoparticle novel object shape public health relevance research study simulation skills theories tool tumor two-dimensional

项目摘要

DESCRIPTION (provided by applicant): The measurement of magnetic properties of tissues in the human body is fast becoming a key element in studying disease with magnetic resonance imaging (MRI) and in molecular imaging. The magnetic properties of a subvoxel object usually cannot be determined from a given magnitude image in MRI. Although the magnetic susceptibility difference between an object and its surrounding tissue leads to a signal loss in the nearby tissue, the combination of magnitude and phase images can be used to quantify the magnetic property of any given object in MR images. A novel inverse method using this feature will be fully developed in this proposal, especially for a few voxel or subvoxel objects. This method requires the use of complex MRI data and naturally accounts for the partial volume effect, dephasing effect (i.e., signal loss), and the phase aliasing effect. Compared to other methods, this method does not require any a priori information of the object of interest. The uncertainty of the method depends on the signal-to-noise ratio and resolution of images. Three specific aims are proposed in this research. The first aim is to determine the magnetic moment of a spherical object and an infinitely long cylindrical object. The former represents a 3D problem while the latter represents a 2D problem. Fundamental electromagnetism guarantees that the magnetic moment of any small object in 3D can be well approximated by the magnetic moment of a sphere. Both simulations and phantom experiments will be conducted to validate the method and investigate the uncertainty of the method. The second aim is to apply the method on existing human and animal images. This is to demonstrate the feasibility of the method on practical images. The third aim is to resolve the magnetic susceptibility and volume of the object individually. Since it is obvious that the volume of an object much less than a voxel such as a nanoparticle in images cannot be determined, it is important to study the limitation of the proposed method. This work could have a major impact on studying aging or molecular imaging through the use of nanoparticles. Evidence indicates that 2-amyloid plaque is related to Alzheimer's disease. Animal studies have shown that amyloid deposits lead to hypointense spots at an early stage of Alzheimer's disease. Quantification of the property of each individual dark spot may become a predictor for monitoring the progression of the disease. Currently, no non-invasive tool other than number counting is available for accurately quantifying microbleeds or hypointense spots in the brain. Nanoparticles have been widely used in MRI for tagging cells in molecular imaging. A reliable in vivo method is needed to quantify the concentration of nanoparticles labeling cells that interact with diseased tissue. This method can do that with numerous identical nanoparticles. In summary, this research has the potential to contribute to the better diagnosis and function of disease in MRI. PUBLIC HEALTH RELEVANCE: The proposed method may become a predictor of Alzheimer's disease in the long run. It may become a useful tool for the design of personalized medicine. The benefit of this research to the public health is obvious.

描述(申请人提供)：人体组织磁性的测量正在迅速成为利用磁共振成像(MRI)和分子成像研究疾病的关键因素。在磁共振成像中，亚体素对象的磁特性通常不能从给定的震级图像中确定。尽管物体与其周围组织之间的磁化率差异导致附近组织中的信号丢失，但幅度和相位图像的组合可用于量化MR图像中任何给定物体的磁性。在该方案中，将充分开发一种使用该特征的新的逆方法，特别是对于少数体素或亚体素对象。这种方法需要使用复杂的MRI数据，并自然地考虑了部分体积效应、去相效应(即信号损失)和相位混叠效应。与其他方法相比，该方法不需要感兴趣对象的任何先验信息。该方法的不确定度取决于图像的信噪比和分辨率。本研究提出了三个具体目标。第一个目标是确定球形物体和无限长圆柱物体的磁矩。前者代表3D问题，而后者代表2D问题。基本电磁学保证了3D中任何小物体的磁矩都可以很好地用球体的磁矩来近似。将通过仿真和模型实验来验证该方法，并研究该方法的不确定度。第二个目标是将该方法应用于现有的人和动物图像。这是为了在实际图像上验证该方法的可行性。第三个目标是分别求解物体的磁化率和体积。由于图像中远小于体素的物体(如纳米颗粒)的体积显然无法确定，因此研究所提出的方法的局限性是很重要的。这项工作可能会对研究衰老或通过使用纳米粒子进行分子成像产生重大影响。有证据表明，2-淀粉样斑块与阿尔茨海默病有关。动物研究表明，淀粉样蛋白沉积会导致阿尔茨海默病早期的低信号斑点。量化每个个体黑斑的性质可能成为监测疾病进展的一个预测指标。目前，除了数字计数外，还没有其他非侵入性工具可用于准确量化大脑中的微出血或低信号斑点。纳米粒子在磁共振成像中被广泛用于标记分子成像中的细胞。需要一种可靠的体内方法来量化标记与疾病组织相互作用的细胞的纳米颗粒的浓度。这种方法可以用大量相同的纳米颗粒做到这一点。综上所述，本研究有可能有助于MRI对疾病的更好的诊断和功能。公共卫生相关性：从长远来看，建议的方法可能成为阿尔茨海默病的预测指标。它可能成为个性化药物设计的有用工具。这项研究对公众健康的好处是显而易见的。