Sparsely Sampled 3D EPSI and Compressed Sensing Reconstruction of HIV Adults

HIV 成人的稀疏采样 3D EPSI 和压缩感知重建

• 批准号: 8732451
• 负责人: Rajakumar Nagarajan
• 金额: $ 18.7万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-01 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8732451
• 关键词: 13 year old; AIDS Dementia Complex; AIDS neuropathy; Acceleration; Acquired Immunodeficiency Syndrome; Adult; Age; Algorithms; American; Anisotropy; Attention; Basal Ganglia; Biochemical; Brain; Brain Mapping; Brain Part; Brain region; CD4 Lymphocyte Count; Centers for Disease Control and Prevention (U.S.); Cerebrum; Chemicals; Choline; Clinical; Clinical dementia rating scale; Cognitive; Cognitive deficits; Complex; Corpus Callosum; Creatine; Data; Data Set; Dementia; Development; Diagnosis; Diffuse; Diffusion; Diffusion Magnetic Resonance Imaging; Dimensions; Disease; Gender; Glutamates; Glutamine; Glutathione; HIV; HIV Infections; HIV Seropositivity; Human; Image; Imaging Techniques; Imaging technology; Individual; Infection; Inflammatory; Inositol; Life; Literature; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Measurement; Measures; Metabolic; Methods; Metric; Modeling; Monitor; N-acetylaspartate; Neuraxis; Neurocognitive; Neurologic Symptoms; Neurons; Outcome; Outcome Study; Pathology; Patients; Pharmaceutical Preparations; Phase; Process; Process Assessment; Protocols documentation; Protons; Reporting; Research; Research Personnel; Resolution; Role; Sampling; Scanning; Scheme; Signal Transduction; Staging; Taurine; Techniques; Time; Tissues; base; clinically relevant; data acquisition; disorder prevention; gamma-Aminobutyric Acid; improved; in vivo; innovation; magnetic resonance spectroscopic imaging; neurochemistry; neuroimaging; neuroinflammation; novel; public health relevance; reconstruction; scyllo-inositol; spectroscopic imaging; tool; two-dimensional; water diffusion; white matter

DESCRIPTION (provided by applicant): The Center for Disease Control and Prevention estimates that 1,148,200 Americans aged 13 years and older are living with HIV infection, including 207,600 (18.1%) who are unaware of their infection. According to pathological data, central nervous system (CNS) involvement is commonly found during the early phase of infection. In vivo proton magnetic resonance spectroscopy studies of HIV-infected humans have demonstrated significant changes of metabolites observed in the brain N-acetylaspartate, creatine, choline, glutamate, glutamine, myo-inositol with varying changes in different brain regions. Diffusion tensor imaging (DTI) can be used to derive quantitative in vivo measurements of region-specific and diffuse brain alterations. DTI studies have demonstrated changes of mean diffusivity (MD) and fractional anisotropy (FA) in the various parts of brain. Diffusion abnormalities involving the frontal white matter and the corpus callosum have also been observed in patients infected with HIV. Single-voxel or two-dimensional (2D) magnetic resonance spectroscopic imaging (MRSI) technique with long and short echo time (TE) has been used for many years to study HIV. A drawback of the three-dimensional (3D) MRSI technique using conventional phase encoding in three directions to traverse k-space is the long time required to acquire large-volume 3D datasets. Hence, the scan time necessary for the acquisition of 3D high- resolution MRSI data with adequate spatial coverage may be prohibitively long for clinical exams. Thus, new imaging and bio-chemical characterization techniques are needed to allow repeated, non-invasive assessment of these processes in vivo. There is a need for whole brain 3D-EPSI using short TE to get 3D maps of brain metabolite distributions even though the current version of the 3D EPSI uses long TE and the total duration is more than 20 minutes. Novel acquisition using non- uniformly under sampled (NUS) 3D EPSI with compressed sensing (CS) reconstruction can further accelerate the MRSI acquisition by approximately 3-4 times. Hence the specific aims of the study are as follows: (1) to implement and optimize a volumetric 3D NUS based EPSI sequence on a Siemens 3T Skyra MRI scanner, and to reconstruct the NUS data using CS reconstruction with excellent signal fidelity; (2) to record NUS-based 3D EPSI data and DTI in 30 HIV patients and to compare the outcome with 30 healthy controls (3) to combine DTI derived FA and MD and to compare the findings with metabolite concentrations and nadir CD4 cell count. We hypothesize that the NUS based 3D EPSI acquisition will be 4 times faster than that of the current fully encoded version. An expected outcome of this study is the development of a volumetric 3D EPSI scan in HIV patients that can select metabolites from multiple brain regions in less than 10 minutes. The whole brain neurochemical changes measured by the 3D EPSI technique will be correlated with that of DTI and nadir CD4 cell count to better understand the role of CNS involvement in HIV pathology.

描述（由申请人提供）：预防疾病控制与预防中心估计，1,148,200名13岁及以上的美国人患有艾滋病毒感染，其中包括207,600（18.1％），他们不知道自己的感染。根据病理数据，中枢神经系统（CNS）的参与通常在感染的早期阶段发现。对感染HIV的人的体内质子磁共振光谱研究研究表明，在脑N-乙酰天冬氨酸，肌酸，胆碱，谷氨酸，谷氨酸，肌醇，肌醇，肌醇，不同大脑区域的变化变化的代谢物发生了显着变化。扩散张量成像（DTI）可用于在区域特异性和弥漫性脑改变的体内测量中得出定量。 DTI研究表明，大脑各个部分中平均扩散率（MD）和分数各向异性（FA）的变化。在感染HIV的患者中，还观察到涉及额叶白质和call体的扩散异常。单腔或二维（2D）磁共振光谱成像（MRSI）技术具有长时间和短回声时间（TE）多年来研究HIV。三维（3D）MRSI技术的缺点，使用传统的相位编码在三个方向上以遍历k空间，这是获取大量3D数据集所需的长时间。因此，在临床检查中，获得足够空间覆盖的3D高分辨率MRSI数据所需的扫描时间可能会很长。因此，需要新的成像和生物化学表征技术，以便在体内重复对这些过程进行无创的评估。即使当前的3D EPSI的当前版本使用较长的te，并且总持续时间超过20分钟，也需要使用短TE获得整个大脑3D-EPSI获得脑代谢物分布的3D地图。在采样（NUS）3D EPSI下使用压缩传感（CS）重建的新型采集可以进一步加速MRSI的收购约3-4次。因此，该研究的具体目的如下：（1）在Siemens 3T Skyra MRI扫描仪上实施和优化基于3D NUS的EPSI序列，并使用具有出色信号忠诚度的CS重建来重建NUS数据； （2）在30名HIV患者中记录基于NUS的3D EPSI数据和DTI，并将结果与​​30个健康对照组（3）进行比较，以结合DTI衍生的FA和MD，并将结果与​​代谢物浓度和NADIR CD4细胞计数进行比较。我们假设基于NUS的3D EPSI采集将比当前完全编码的版本快4倍。这项研究的预期结果是在HIV患者中开发了体积3D EPSI扫描，可以在不到10分钟的时间内从多个大脑区域中选择代谢物。通过3D EPSI技术测量的整个大脑神经化学变化将与DTI和NADIR CD4细胞计数相关，以更好地了解CNS参与在HIV病理学中的作用。