DIFFUSION TENSOR IMAGING: A CLINICAL DTI PROTOCOL

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。本研究的目标是继续完善和改善扩散张量成像（DTI）的研究人员和合作者的P41 RR 09784？斯坦福大学的先进磁共振技术中心？努力扩散张量成像（DTI）是一种很有前途的新技术，用于评估白色物质（WM）的结构完整性和连接性。我们已经将DTI添加到各种各样的脑MR协议中，例如急性和慢性中风，创伤，多发性硬化症，早产儿以及许多精神病学协议。各种研究的初步结果表明，DTI可以从这4分钟的扫描中预测患者的认知和运动表现。沿沿着六个非共线方向测量扩散。对于每个梯度方向，采集四个图像并取平均值。采集了两张无弥散加权（B = 0 s/mm 2）的图像，并采集了一组B = 0 s/mm 2的CSF归零反转恢复（IR）图像;这些图像用于解扭曲弥散加权图像，这导致了比使用非IR B=0图像更稳健的解扭曲。DTI序列需要4分钟。DTI的一个更有趣的方面涉及大脑中白色物质方向的3-D可视化。虽然分数各向异性图通常以灰度显示，但实际的水质子扩散矢量可以叠加到彩色图上。我们一直在评估各种方式显示复杂的质子扩散信息在一个有意义的和翔实的格式。一种这样的方法涉及原始数据的过采样，随后是放置在3-D配色方案和纤维跟踪算法模型中的矢量流。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The goal of this research continues to refine and improve the methodology of diffusion tensor imaging (DTI) for the investigators and collaborators on the P41 RR09784 ?Center for Advanced MR Technology at Stanford? effort. Diffusion tensor imaging (DTI) is a promising new technique for the assessment of white matter (WM) structural integrity and connectivity. We have added DTI to a wide variety of brain MR protocols such as acute and chronic stroke, trauma, multiple sclerosis, premature babies as well as to a number of psychiatric protocols. Preliminary results from a variety of studies suggest that DTI may predict the cognitive and motor performances of a patient from this 4-minute scan. Diffusion is measured along six non-collinear directions. For each gradient direction, four images were acquired and averaged. Two images with no diffusion weighting (b = 0s/mm2) were acquired and a set of Inversion Recovery (IR) images for CSF nulling were acquired with b = 0s/mm2; these images were used to unwarp the diffusion weighted images, which resulted in a more robust unwarping than using the non-IR b=0 images. The DTI sequence requires 4 minutes. One of the more interesting aspects of DTI involves the 3-D visualization of the white matter orientation in the brain. While the fractional anisotropy maps are typically displayed in a gray scale, the actual water proton diffusion vectors may be overlaid onto a color map. We have been evaluating various ways of displaying the complex proton diffusion information in a meaningful and informative format. One such approach involves oversampling of the original data followed by a vector stream placed within a 3-D color scheme and in models for fiber tracking algorithms.