HIGH RESOLUTION BOLD VENOGRAPHIC IMAGING

描述（申请人摘要中的逐字引用）：一种新的静脉造影成像 已经开发出一种方法来探测大脑功能。该方法依赖于 由血液引起的静脉血中MR信号的变化 氧合水平依赖性（BOLD）效应 脱氧血红蛋白这些变化导致MR图像中的信号损失， 静脉血与周围脑实质的抵消。当这个 信号损失被检查为回波时间的函数，它揭示了一个独特的 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。在这份提案中，我们计划 使用这种BOLD静脉造影（HRBV）方法的高分辨率3D版本， 覆盖了大脑中很大一部分区域具体而言，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， 作为血管尺寸、氧饱和度和场强的函数的信号损失。 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。这一能力将在一些 大脑中的生理挑战状态，使用氧气和二乙酰唑胺。是 预计将开发和验证一种强大的3D方法， 这种方法在将来的临床应用中通常是可行的。的一部分 为了实现这一目标，我们将重新审视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 更高质量的图像和更高的准确性和精度。最后我们将 测试一种新的脑功能成像方法， 对场失真及其相关的信号损失具有降低的灵敏度 当使用非常长的回波时间时。今天，先进的技术可以处理 实现这些目标所需的许多关键实验问题。的 这项研究的成功可能会提供一种更好的方法来评估大脑功能， 功能磁共振成像实验，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.