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的双量子相干性（IDQC）MR成像，特别关注大脑中的应用。这是基于以下主要假设：IDQC提供了与各种重要的MRI应用有关的新颖而独特的成像对比度，这些对比度与多种重要的MRI应用有关，包括脑FMRI，肿瘤中缺氧的检测，扩散加权成像以及小梁骨的表征。但是，由于该技术的早期性质，我们认为对IDQC成像对比机制的基本原理有更好的理解并确定在IDQC成像的应用之前确定成像优化的关键因素至关重要。因此，该提案的具体目的是根据固有参数（包括放松，扩散，对磁敏感性分布的敏感性以及IDQC信号对微结构对微结构的依赖性）和实验参数（磁场强度，脉冲时刻，脉冲时机，相干选择，检测方法）来量化新型IDQC图像对比度。这些目标是通过研究设计和方法在开发具有高SNR和独特对比度特征的最佳IDQC成像技术方面的发展，并在理论分析和计算机模拟的指导下，并通过1.5 9.4和14t的幻象和大鼠大脑进行验证，在1.5 9.4和14t，正常人类志愿者在1.5T处的脑袋进行了验证。我们的脉冲序列优化将根据IDQC信号的唯一特征来从信号激发，信号检测和图像后处理中进行接近。这项研究的结果应导致对IDQC成像对比的基本因素的定量，并大大改进了适用于不同田间强度下各种新型应用的成像技术。