GRADIENT ECHO PHASE AND SUSCEPTIBILITY IMAGING OF THE MOUSE BRAIN

小鼠大脑的梯度回波相位和磁化率成像

• 批准号: 8363205
• 负责人: CHARLES R DIBB
• 金额: $ 0.61万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8363205
• 关键词: Animals; Attention; Brain; Dependence; Disease; Early Diagnosis; Exhibits; Funding; Gadolinium; Grant; Image; Iron; Magnetism; Microscopy; Mus; National Center for Research Resources; Nuclear; Perfusion; Phase; Predisposition; Principal Investigator; Prohance; RHOA gene; Research; Research Infrastructure; Resolution; Resources; Saline; Scanning; Series; Source; Symptoms; Tissues; United States National Institutes of Health; cost; gadolinium oxide; in vivo; nervous system disorder; sample fixation

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The early diagnosis of a neurological disease often aids in the treatment of disease symptoms. Among other things, iron accumulation has been associated with several neurological diseases (Sehgal et al. 2005). Differences in magnetic susceptibility images are particularly sensitive to tissues containing iron. In nuclear MR, susceptibility imaging exploits these susceptibility differences to extract phase information from a gradient echo sequence scan and generate images that achieve a form of contrast not found in standard magnitude images. In 2005, it was suggested by Sehgal et al that susceptibility imaging will be faster and yield better SNR at higher field strengths. Characterizing magnetic susceptibility differences at different field strengths would allow the improvements from increasing the field strength used for susceptibility imaging to be quantified. The specific aims of this project are to examine and characterize: 1) the effect of perfusion fixations on susceptibility images, noting differences in scans performed in vivo and ex vivo following perfusion. 2) any field strength dependence exhibited in the susceptibility images. 3) T2* decay by taking a series of scans varying TE, paying particular attention to non-exponential decay and its relationship to phase using combined magnitude and phase images. I will gather phase and susceptibility images of the mouse brain using a gradient echo sequence (GPSW). The mice brains will be scanned under each of the following 3 conditions: 1) In vivo at 7T, with TE H12 ms, TR H 100 ms, alpha H 20 degrees, averaging enough excitations offline to arrive at a SNR similar to condition 2 at 9T. 2) Perfusion with saline at 1T, 2T, 7T, and 9T. 3) Perfusion with gadolinium (ProHance) at 1T, 2T, 7T, and 9T, TE H7ms, TR H100 ms, alpha H90 degrees, NEX = 2 Scan resolution for the 7T and 9T scans will be 256 x 128 x 128 for a 22mm x 11mm x 11mm, 3D isotropic rectangle image. For 1T and 2T, resolution will be 128 x 64 x 64. After the in vivo scans, it is desired, but not necessary, to perform perfusion on the brains of the mice that survive for use in conditions (2) and (3) above. If those animals are not suitable for perfusion for some reason, then additional mice will be required for the perfusion studies.

该子项目是利用资源的众多研究子项目之一 由 NIH/NCRR 资助的中心拨款提供。子项目的主要支持 并且子项目的主要研究者可能是由其他来源提供的， 包括其他 NIH 来源。 子项目可能列出的总成本 代表子项目使用的中心基础设施的估计数量， NCRR 赠款不直接向子项目或子项目工作人员提供资金。 神经系统疾病的早期诊断通常有助于治疗疾病症状。 除其他外，铁积累与多种神经系统疾病有关（Sehgal 等，2005）。磁化率图像的差异对含铁组织特别敏感。 在核磁共振中，磁化率成像利用这些磁化率差异从梯度回波序列扫描中提取相位信息，并生成可实现标准幅度图像中未发现的对比度形式的图像。 2005 年，Sehgal 等人提出，磁化率成像在更高的场强下会更快，并产生更好的信噪比。 表征不同场强下的磁化率差异将允许量化增加用于磁化率成像的场强所带来的改进。 该项目的具体目标是检查和表征： 1) 灌注固定对磁敏图像的影响，注意灌注后体内和离体扫描的差异。 2) 磁化率图像中表现出的任何场强依赖性。 3) 通过进行一系列改变 TE 的扫描来进行 T2* 衰减，特别注意使用组合幅度和相位图像的非指数衰减及其与相位的关系。 我将使用梯度回波序列 (GPSW) 收集小鼠大脑的相位和磁化率图像。 将在以下 3 种条件下对小鼠大脑进行扫描： 1) 体内 7T，TE H12 ms、TR H 100 ms、α H 20 度，离线平均足够的激励，以达到与 9T 条件 2 类似的 SNR。 2) 1T、2T、7T、9T 生理盐水灌注。 3) 在 1T、2T、7T 和 9T 下使用钆 (ProHance) 进行灌注，TE H7ms、TR H100 ms、α H90 度、NEX = 2 对于 22mm x 11mm x 11mm 3D 各向同性矩形图像，7T 和 9T 扫描的扫描分辨率将为 256 x 128 x 128。 对于 1T 和 2T，分辨率将为 128 x 64 x 64。 体内扫描后，需要但不是必须对存活的小鼠的大脑进行灌注，以供在上述条件（2）和（3）中使用。 如果这些动物由于某种原因不适合灌注，则需要额外的小鼠进行灌注研究。