QUANTIFICATION OF CEST CONTRAST AGENT CONCENTRATION USING PROTON SPIN-LOCK MRI

这个子项目是许多利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 MRI造影剂通过改变磁共振成像的弛豫时间来改善身体结构的可见性。 周围组织使用的化学交换依赖饱和转移（CEST）技术 与具有质子交换位点的试剂组合可用作对照 通过显著改变水质子信号的幅度来实现该机制。各种 化学交换位点已经被开发为外源性CEST造影剂， 生理条件。使用非共振辐射的磁化转移（MT）技术 的大分子质子池目前用于基于这些产生对比度 大分子-质子相互作用我们的假设是，基于T1的MRI将更少 易受线形变化的影响，并在检测CEST试剂中提供更高的灵敏度。 该子项目的目的是开发一种敏感和稳健的方法， 通过评估在组织中摄取的表现出CEST效应的药剂的浓度， 通过自旋锁定的化学交换速率。 研究目的： 1.开发一种分离CEST造影剂的存在并定量CEST造影剂的方法， 存在的代理数量。 2.为了验证我们的模型，使用在不同pH下用几种CEST试剂创建的幻影， 浓度的 3.证明我们的模型可以可靠地用于量化CEST造影剂 在动物模型中的浓度。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. MRI Contrast agents improve the visibility of body structures by altering the relaxation times of surrounding tissue. Chemical exchange dependant saturation transfer (CEST) techniques used in combination with agents that possess a proton exchange site can be used as a contrast mechanism by significantly changing the magnitude of the water proton signal. Various chemical exchange sites have been developed as exogenous CEST contrast agents under physiological conditions. Magnetization transfer (MT) techniques using off-resonance irradiation of the macromolecular proton pool are currently utilized to generate contrast based on these macromolecule-proton interactions. Our hypothesis is that T1¿ based MRI will be less susceptible to line shape changes and provide higher sensitivity in detecting CEST agents. The purpose of this subproject is to develop a sensitive and robust method to quantify the concentration of an agent exhibiting a CEST effect taken up in tissues by assessing the chemical exchange rates via spin locking. Study Aims: 1. To develop a method to isolate the presence of a CEST contrast agent and quantify the amount of agent present. 2. To validate our model using phantoms created with several CEST agents at varying pH's and concentrations. 3. To demonstrate that our model can be reliably used to quantify CEST contrast agent concentration in animal models.