HIGH RESOLUTION BOLD VENOGRAPHIC IMAGING

描述(逐字摘自申请者的摘要)：一种新的静脉成像方法已经开发出来，用于探测大脑功能。该方法依赖于 血液在静脉血中引起的磁共振信号变化 氧合水平依赖(BOLD)效应 脱氧血红蛋白。这些变化导致磁共振图像中的信号损失，原因是 取消静脉血与周围脑实质的联系。当这件事 信号损失是作为回波时间的函数进行检查的，它揭示了 信号，非指数衰减，指示氧的状态 组织中的饱和度和静脉血容量。在这项提案中，我们计划 使用这种大胆的静脉造影(HRBV)方法的高分辨率3D版本来 覆盖大脑中感兴趣的大片区域。具体来说，我们希望 了解血管内和血管外效应在导致这种情况中的作用 信号损失是血管大小、血氧饱和度和场强的函数。 有了这些知识，我们将尝试预测静脉血氧饱和度 和静脉血容量。这一能力将在许多情况下使用 大脑中使用氧气和Diamox的生理障碍状态。它是 预计将开发并验证强大的3D方法，以使 这种方法在未来的临床应用中总体上是可行的。作为以下内容的一部分 为了达到这个目标，我们将重温血氧饱和度和血液的量化 使用T1降低造影剂进行体积测量。这将导致 更高质量的图像以及更高的准确度和精确度。最后，我们会 测试一种新的脑功能成像方法，它提供了以下优势 对场失真及其相关信号损失的敏感度降低 当使用非常长的回声时间时。今天，已经有了精致的技术来处理 实现这些目标所需的许多关键实验问题。这个 这项研究的成功可能为评估脑功能提供了一种更好的手段 功能磁共振实验，用于诊断隐匿性静脉病变，研究肿瘤和其他 血管相关疾病。

DESCRIPTION (Verbatim from the Applicant's Abstract): A new venographic imaging method has been developed to probe brain function. The method relies on the changes induced in the MR signal in venous blood caused by the blood oxygenation level dependent (BOLD) effect from the presence of de-oxyhemoglobin. These changes cause a signal loss in the MR images due to the cancellation of venous blood with surrounding brain parenchyma. When this signal loss is examined as a function of echo time it reveals a unique signature, a non-exponential decay, indicative of the state of oxygen saturation and venous blood volume in the tissue. In this proposal, we plan to use a high resolution 3D version of this BOLD venographic (HRBV) method to cover a large region of interest in the brain. Specifically, we wish to understand the roles of intravascular and extravascular effects in causing this signal loss as a function of vessel size, oxygen saturation and field strength. Given this knowledge, we will attempt to predict both venous oxygen saturation and venous blood volume. This capability will be used under a number of physiologically challenged states in the brain using oxygen, and diamox. It is expected that a robust 3D methodology will be developed and validated to make this approach generally viable for clinical utility in the future. As part of this goal, we will revisit the quantification of oxygen saturation and blood volume measurements using a T1 reducing contrast agent. This will lead to higher quality images and improved accuracy and precision. Finally, we will test a new approach to functional brain imaging which offers the advantage of having a reduced sensitivity to field distortion and its associated signal loss when very long echo times are used. Today, refined techniques exist to handle many of the key experimental issues needed to accomplish these goals. The success of this research may offer a better means to evaluate brain function in fMRI experiments, to diagnose occult venous lesions, to study tumors and other vascular related diseases.