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.

该研究的目的是开发新的磁共振成像方法来测量 组织中水的表观扩散系数（ADC）作为时间频率的函数，并且 评估所谓的扩散光谱是否有助于表征肿瘤和监测其 不同病理条件下组织内水的 ADC 发生变化。 包括癌症，并产生扩散加权磁共振中描绘的图像对比度 扩散成像（DWI）已被证明在小动物成像中非常有用。 肿瘤的状态和反应，并揭示有关组织特征的信息，例如细胞结构 可通过其他方式获得 ADC 的常规测量结果，揭示限制对自由的影响。 在特定空间尺度上的扩散由扩散时间间隔决定，通常是几个 因此，ADC 的变化主要由该限制势垒的密度变化决定。 间距，并且从 ADC 测量中无法获得有关在某个位置发生的结构变化的信息。 我们的目标是通过测量所谓的扩散来开发一种新的扩散成像方法。 因此，将获得使用新颖的梯度波形的光谱，该测量对光谱非常敏感。 因此，那些影响更短时间尺度的限制的结构特征将是。 获得的对比度对细胞内的变化更敏感。 具有独特的能力，能够提供有关制度中扩散的信息，并可从中得出推论 我们将进一步开发这些方法来测量改变扩散的细胞内组织结构。 在更短的时间和更精细的空间尺度上扩散，然后应用这些方法来衍生新的 为了实现这些目标，我们将实施振荡梯度自旋回波。 (OGSE) 测量 9.4T 的水扩散，以在刻度上探测组织结构 ¿ 1微米。 我们将根据这些数据生成与孔隙（细胞）尺寸、固有水扩散速率和表面相关的图像。 我们将确定 OGSE 方法是否可以检测细胞内空间的体积比。 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 荷瘤动物治疗前和治疗后的 MR 测量值将与治疗前和治疗后的结果相关。 此外，我们将预测OGSE的结果。 通过对复制组织的隔室系统中的水进行计算机模拟来进行测量 结构。