MRI Diffusion in Tumors Using Oscillating Gradients

使用振荡梯度进行肿瘤 MRI 扩散

• 批准号: 7577357
• 负责人: John C Gore
• 金额: $ 26.46万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-03-15 至 2011-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7577357
• 关键词: Affect; Aftercare; Animal Model; Animals; Apoptosis; Behavior; Brain Neoplasms; Cell Density; Cell Size; Cells; Cellular Morphology; Cellular Structures; Cellularity; Characteristics; Computer Simulation; Data; Data Set; Diffuse; Diffusion; Diffusion Magnetic Resonance Imaging; Frequencies; Hela Cells; Histology; Image; Immunochemistry; In Vitro; Magnetic Resonance Imaging; Malignant Neoplasms; Mammary Neoplasms; Measurement; Measures; Methods; Microtubules; Mitosis; Mitotic Cell Cycle; Modeling; Monitor; Motivation; Mus; Nuclear; Organelles; Pharmaceutical Preparations; Pharmacological Treatment; Physiologic pulse; Research; Structure; Surface; Suspension substance; Suspensions; System; Techniques; Time; Tissues; Variant; Water; Water Movements; Weight; base; density; imaging modality; in vivo; in vivo Model; neoplastic cell; novel; novel strategies; oscillating gradient spin echo; response; time interval; tool; tumor; tumor growth; tumor progression; water diffusion

The aims of the research proposed are to develop new magnetic resonance imaging methods that measure the apparent diffusion coefficient (ADC) of water in tissues as a function of temporal frequency, and to evaluate whether so-called diffusion spectra are useful for characterizing tumors and for monitoring their response to treatment. Variations of ADC of water occur within tissues in various pathological conditions including cancer, and give rise to the image contrast depicted in diffusion-weighted magnetic resonance imaging (DWI). Diffusion measurements have proven useful in small animal imaging for characterizing the state and response of tumors, and reveal information on tissue characteristics such as cellularity not obtainable by other means. Conventional measurements of ADC reveal the effects of restrictions to free diffusion on a specific spatial scale determined by the diffusion time interval, and typically this is several microns. Variations in ADC are thus dominated by variations in the density of restricting barriers of this spacing, and no information is available from ADC measurements about structural changes that occur at a smaller scale. We aim to develop a new approach to diffusion imaging by measuring so-called diffusion spectra using novel gradient waveforms. Measurements will thereby be obtained that are very sensitive to those structural features that affect restriction over very much shorter time scales. Images will thus be obtained in which the contrast is more sensitive to variations within cells. Oscillating gradient methods are uniquely capable of providing information on diffusion in the regime in which inferences can be drawn about the intracellular tissue structures that modify diffusion. We will further develop these methods to measure diffusion over much shorter times and finer spatial scales, and will then apply these methods to derive new information on tumors in vivo. To achieve these aims we will implement oscillating gradient spin echo (OGSE) measurements of diffusion of water at 9.4T to probe tissue structure on a scale ¿ 1 micron. From these data we will produce images related to the pore (cell) size, intrinsic water diffusion rates and surface to volume ratio of spaces within tissues. We will establish whether OGSE methods can detect intracellular changes in cells following pharmacological treatments and during mitosis, and what changes are detectable in tumor bearing animals before and after treatment. The MR measurements will be correlated with histological image data and immunochemistry. In addition, we will predict the results of OGSE measurements by performing computer simulations of water in compartmental systems that replicate tissue structure.

提出的研究的目的是开发测量新的磁共振成像方法 组织中水的明显扩散系数（ADC）是临时频率的函数， 评估所谓的扩散光谱是否可用于表征肿瘤并监测其 对治疗的反应。在各种病理条件下组织中ADC的变化发生 包括癌症，并引起扩散加权磁共振中描述的图像对比度 成像（DWI）。事实证明，扩散测量在小动物成像中有用用于表征 肿瘤的状态和反应，并揭示有关组织特征（例如细胞）的信息 可以通过其他方式获得。 ADC的常规测量揭示了限制自由的影响 在特定的空间尺度上扩散由扩散时间间隔确定，通常这是几个 微米。因此，ADC的变化主要由限制障碍的密度变化 间距，并且没有从ADC测量中获得有关发生结构变化的信息 较小的规模。我们旨在通过测量所谓的差异来开发一种新的扩散成像方法 使用新型梯度波形的光谱。因此，将获得非常敏感的测量 那些影响限制时间尺度较短的结构特征。因此图像将是 获得的对比度对细胞内的变化更敏感。振荡梯度方法是 独特的能力提供有关在制度中传播的信息，在该制度中可以借鉴信息 修饰扩散的细胞内组织结构。我们将进一步开发这些方法来衡量 在较短的时间和更细的空间尺度上扩散，然后将这些方法应用于新的 有关体内肿瘤的信息。为了实现这些目标，我们将实施振荡梯度旋转回声 （OGSE）水在9.4T处的扩散以探测量表上的组织结构的测量。1微米。从 这些数据我们将产生与孔（单元）大小，内在水扩散率和表面相关的图像 组织内空间的体积比。我们将确定OGSE方法是否可以检测到细胞内 药物治疗后和有丝分裂期间细胞的变化，以及可检测到的变化 在治疗前后的肿瘤轴承中。 MR测量将与 组织学图像数据和免疫化学。此外，我们将预测OGSE的结果 通过在复制组织的隔室系统中对水的计算机模拟进行测量 结构。