PHYSIOLOGICAL MECHANISMS OF MYOCARDIAL FORCE GENERATION

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 目的：在最佳麻醉方式和剂量下，应用应变张量相图结合位移编码的刺激回波和径向投影成像，可以准确、准确地表征小鼠心脏的整体机械功能和血流灌注。 工作包 --心脏核磁共振研究用射频(RF)线圈的开发和测试。 --开发用于心脏功能小鼠研究的致密脉冲序列。 --利用核磁共振技术为麻醉下的正常小鼠的高通量采集开发全面的心脏功能。 方法：对于核磁共振研究，脉冲序列、成像方案和硬件测试将通过模拟和在CIVM-Duke使用幻影和小鼠的实验来验证 290只正常小鼠(雌雄各半，CB57L、CD-1和FVB株，体重20-30g)将用于LBI和CIVM的[WP 3-4，5-8]的研究。对于LBI研究，小鼠将从塞浦路斯神经学和遗传学研究所或美国杰克逊实验室购买。更多的小鼠将在CIVM订购和使用，以测试和验证拟议的心脏MRI研究。所有研究将按照杜克大学和机构动物保护和使用委员会的研究道德行为规则、塞浦路斯农业部制定的国家规则和欧洲动物研究指令进行。项目协调员和LBI获得塞浦路斯农业部的完全许可，可以在MICE上进行拟议的实验工作 脉冲序列开发和测试：7.0特斯拉扫描仪(在Excite GE操作台上)将用于硬件(鸟笼发射[TX]/接收[RX]线圈和RX相控阵)和密集/灌注脉冲序列的实施、模拟和测试。密集序列将在内部实施，并在模拟器、静止幻影和老鼠上进行测试。一种动态增强的MRI灌注脉冲序列，以前在CIVM的啮齿类动物的肺灌注中实施，将被修改用于心脏小鼠的研究。该序列基于交错径向成像和“滑动窗口锁孔重建”。其他商业上可用的脉冲序列将被测试和优化，用于小鼠心脏功能研究，包括Radial、Carr Purcell Meiom Gill(CPMG)、劣质草[SPGR]和闪光型序列。

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. AIM: Global mechanical function and perfusion of the mouse heart can be accurately and precisely characterized with strain tensor phase mapping with Displacement Encoding with Stimulated Echoes and radial projection imaging, under optimal anesthesia types and doses, using MRI. WORK PACKAGES -- Development and Testing of Radiofrequency (RF) coils for Cardiac MRI studies. -- Development of a DENSE pulse sequence for cardiac functional mouse studies. -- Development of a comprehensive cardiac function for high-throughput acquisitions in normal mice under anesthesia using MRI. METHODOLOGY: For MRI studies, pulse sequences, imaging protocols and hardware tests, will be validated with simulations and in experiments using phantoms and mice at CIVM-Duke 290 normal mice (male and female, CB57L, CD-1, and FVB strains, weightH20-30g) will be used for the studies of [WP 3-4, 5-8], at LBI and CIVM. For the LBI studies, mice will be purchased from the Cyprus Institute of Neurology and Genetics or from The Jackson Laboratory, USA. Additional mice will be ordered and used at CIVM for testing and validation of the proposed cardiac MRI studies. All studies will be performed in accordance with the rules of ethical conduct of research at Duke University and the Institutional Animal Care and Use Committee, and in accordance with national rules set by the Ministry of Agriculture in Cyprus and according to the European Animal Research directives. The project coordinator and the LBI are fully licensed by the Ministry of Agriculture in Cyprus to conduct the proposed experimental work with mice Pulse Sequence Development and Testing: The 7.0 Tesla scanner (on an Excite GE operating console) will be used for implementation, simulation, and testing of hardware (birdcage transmit [TX]/receive [RX] coil, and RX phased array) and the DENSE/perfusion pulse sequences. A DENSE sequence will be implemented in-house, and tested on the simulator, and on stationary phantoms, and mice. A dynamic contrast enhanced MRI perfusion pulse sequence, previously implemented for pulmonary perfusion in rodents at CIVM, will be modified for use in cardiac mice studies. The sequence is based on interleaved radial imaging and a 'sliding window keyhole reconstruction'. Other commercially available pulse sequences will be tested and optimized for mouse cardiac functional studies, including Radial, Carr Purcell Meiboom Gill (CPMG), Spoiled Grass [SPGR], and FLASH type sequences.