DEVELOPMENT OF ADVANCED CHEMICAL SHIFT IMAGING (CSI) TECHNIQUES

化学位移成像（CSI）是用于体内成像的首选方法。 定域光谱学 然而，仍有一些持续存在的障碍， 仍然适用于质子以外的原子核，特别是31P 和19F CSI在本申请的项目中提出。 一是 灵敏度低。 第二和几个后果，测量 是长的，因此，在临床会话中只能观察到一个核， 即使来自另一个人的信息是重要的和需要的。 三是 目前傅立叶重建方法，广泛使用，因为他们 计算的便利性和简单性，导致 将来自一个体素的信号与其相邻体素的信号混合。 这个艺术品 称为体素出血，导致光谱污染并影响CSI 梗概. 我们建议从三个角度解决这些困难。 第一，使用 从1H到不太敏感的31P的偏振转移技术， 增加后者的信号，并将用于项目II。 二是 开发同时采集技术，允许1H去耦 单次临床检查期间的31 P和19 F CSI采集。 第三、 开发非傅立叶变换技术， 将提高CSI的准确性 重建

Chemical Shift Imaging (CSI) is the method of choice for in vivo localized spectroscopy. However, several persistent obstacles still remain in its application to nuclei other than protons, specifically 31P and 19F CSI proposed in projects of this application. First, the sensitivity is low. Second and several consequents, the measurements are long, thus, only one nucleus can be observed in a clinical session, even if information from another is significant and sought. Third, the current Fourier reconstruction methods, widely used because of their computational convenience and simplicity, result in an artifact that intermixes signal from one voxel, with its its neighbors. This artifact, known as A voxel bleed, leads to spectral-contamination and impacts CSI in general. We propose to address these difficulties from three angles. First, to use polarization transfer techniques from 1H to the less sensitive 31P to increase the signal of the latter and to be used in project II. Second, to develop simultaneous acquisition techniques that will allow 1H decoupled 31P and 19F CSI acquisition during a single clinical examination. Third, to develop non-Fourier transform techniques that, using prior knowledge from the proton images, will improve the accuracy of CSI reconstruction.