Biophysical Basis of Brain iDQC MR Imaging

大脑 iDQC MR 成像的生物物理基础

基本信息

批准号：
6733610
负责人：
JIANHUI ZHONG
金额：
$ 26.24万
依托单位：
UNIVERSITY OF ROCHESTER
依托单位国家：
美国
项目类别：
财政年份：
2002
资助国家：
美国
起止时间：
2002-04-01 至 2007-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6733610
关键词：
bioengineering /biomedical engineering bioimaging /biomedical imaging biophysics brain imaging /visualization /scanning clinical research human subject image enhancement image processing laboratory rat magnetic resonance imaging phantom model technology /technique development

项目摘要

The broad, long-term objective of this application is to develop intermolecular double-quantum coherence (iDQC) MR imaging with particular focus on applications in the brain. This is based on the primary hypothesis that iDQC provides novel and unique imaging contrast which is relevant to and potentially useful in a wide variety of important MRI applications, including brain fMRI, detection of hypoxia in tumors, diffusion-weighted imaging, and characterization of trabecular bones. However, owing to the early nature of the technique, we believe that it is crucial to gain a better understanding of fundamentals of iDQC imaging contrast mechanisms, and to determine the key factors for imaging optimization before applications of iDQC imaging become practical. The specific aims of this proposal are therefore to quantify the novel iDQC image contrast in terms of intrinsic parameters (including relaxation, diffusion, sensitivity to magnetic susceptibility distributions, and dependence of iDQC signals on microstructures) and experimental parameters (field strength, pulse timing, coherence selection, detection method). These aims are achieved via research designs and methods in development of optimal iDQC imaging techniques with high SNR and unique contrast characteristics, guided by theoretical analyses and computer simulations, and validated with measurements in phantoms and rat brains at 1.5 9.4 and 14T, and brains of normal human volunteers at 1.5T. Our pulse sequence optimization will be approached from signal excitation, signal detection, and image post-processing, based on the unique characteristics of iDQC signals. The outcome of this study should lead to quantitation of essential factors for iDQC imaging contrast, and much improved imaging techniques applicable for a variety of novel applications at different field strengths.

该应用的广泛、长期目标是开发分子间双量子相干 (iDQC) MR 成像，特别关注大脑中的应用。这是基于 iDQC 提供新颖且独特的成像对比度的主要假设，该成像对比度与各种重要 MRI 应用相关并可能有用，包括脑 fMRI、肿瘤缺氧检测、扩散加权成像和小梁表征骨头。然而，由于该技术的早期性质，我们认为在 iDQC 成像应用变得实用之前，更好地了解 iDQC 成像对比度机制的基本原理并确定成像优化的关键因素至关重要。因此，该提案的具体目标是根据内在参数（包括弛豫、扩散、对磁化率分布的敏感性以及 iDQC 信号对微观结构的依赖性）和实验参数（场强、脉冲定时、相干选择、检测方法）。这些目标是通过研究设计和开发具有高信噪比和独特对比度特性的最佳 iDQC 成像技术的方法来实现的，以理论分析和计算机模拟为指导，并通过在 1.5、9.4 和 14T 下的体模和大鼠大脑以及正常人类志愿者在 1.5T 下。我们将根据iDQC信号的独特特性，从信号激励、信号检测和图像后处理等方面进行脉冲序列优化。这项研究的结果应该能够对 iDQC 成像对比度的基本因素进行定量，并大大改进成像技术，适用于不同场强下的各种新颖应用。