Separation of 23Na Compartments and Semi-Quantitative Determination of the Intracellular Sodium Concentration Using Ultra High Field Magnetic Resonance Imaging

超高场磁共振成像分离 23Na 室并半定量测定细胞内钠浓度

• 批准号: 236524675
• 负责人: Professor Dr. Armin Nagel, Ph.D.
• 金额: --
• 依托单位: Institut für Angewandte Physiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/236524675?language=en
• 关键词: Separation; 23Na; Compartments; Semi; Quantitative

The aim of the current project is the non-invasive separation of different sodium compartments in vivo and the semi-quantitative determination of the intracellular sodium concentration. Different sequences for ultra-high field magnetic resonance imaging (MRI) (7 Tesla) will be developed and evaluated.First, a new sequence that allows for shorter acquisition time and SNR- and SAR-efficient detection of the bi-exponential weighted sodium signal will be developed. To separate different sodium compartments the exact knowledge of the relaxation times is inevitable. Thus, a triple-quantum-filtered (TQF) single voxel spectroscopy (SVS) sequence will be implemented that allows for a rapid measurement of the local (e.g. in tumor tissue) bi-exponential relaxation times.To provide sufficient accuracy and reproducibility for the determination of signal intensities of the different 23Na-MRI techniques, several corrections have to be performed. In addition to the correction of inhomogeneities of the static magnetic field (B0) and the sensitivity profiles of the radiofrequency coils (B1), high resolution information from 1H-MRI will be used to enable a better quantification of the 23Na-MRI signals. In the human body sodium is dissolved in water. Therefore, the tissue sodium concentration should be normalized to the local water content. Thus, a technique for quantitative water mapping will be implemented. In muscular diseases fatty infiltration are often present. The sizes of these structures are often smaller than the spatial resolution of 23Na-MRI. Therefore, a quantitative determination of the muscular fat content and a highly resolved visualization of the fat infiltrations is necessary the correct for partial volume effects. Furthermore, prior knowledge from 1H-MRI data (e.g. bone tissue gives no 23Na-signal) will be incorporated to enable a better 23Na-MR image quality regarding SNR and spatial resolution. Based upon the newly developed techniques and the sequences that are available from prior work, models that allow for a semi-quantitative determination of the intracellular sodium concentration will be developed. After a successful check of the developed method in measurements of well suited phantoms, in vivo evaluation in healthy subjects will be performed. Models for the semi-quantitative determination of the intracellular sodium concentration will be provided for brain and muscle tissue.Finally, examinations of patients with well-defined muscular channelopathies as model diseases will be performed. In these diseases provocation (cooling and muscle exercise) leads to an increase of the intracellular sodium concentration. This increase can be provoked with high reproducibility. Measurements before and after provocation of the muscle tissue will be performed to evaluate the potential to visualize an increase of the intracellular sodium content with the developed methods.

目前项目的目的是无创分离体内不同的钠区室和半定量测定细胞内钠浓度。将开发和评估不同的超高场磁共振成像（MRI）序列（7特斯拉）。首先，将开发一种新的序列，该序列允许更短的采集时间以及对双指数加权钠信号的信噪比和sar有效检测。为了分离不同的钠隔室，必须精确了解弛豫时间。因此，三量子滤波（TQF）单体素光谱（SVS）序列将被实现，允许快速测量局部（例如在肿瘤组织中）双指数弛豫时间。为了提供足够的准确性和可重复性来确定不同的23Na-MRI技术的信号强度，必须进行几次修正。除了校正静态磁场（B0）的不均匀性和射频线圈（B1）的灵敏度曲线外，还将使用来自1H-MRI的高分辨率信息来更好地量化23Na-MRI信号。在人体内，钠溶解在水中。因此，组织钠浓度应与局部含水量归一化。因此，将实施定量水图绘制技术。肌肉疾病常伴有脂肪浸润。这些结构的尺寸通常小于23Na-MRI的空间分辨率。因此，肌肉脂肪含量的定量测定和脂肪浸润的高分辨率可视化是必要的，以正确的部分体积效应。此外，将纳入h - mri数据的先验知识（例如，骨组织没有23na信号），以获得更好的23Na-MR图像质量，包括信噪比和空间分辨率。基于新开发的技术和从先前工作中获得的序列，将开发允许半定量测定细胞内钠浓度的模型。在成功检查所开发的方法在合适的幻影测量后，将在健康受试者中进行体内评估。将为脑和肌肉组织提供半定量测定细胞内钠浓度的模型。最后，对明确的肌肉通道病变作为模型疾病的患者进行检查。在这些疾病中，刺激（降温和肌肉运动）导致细胞内钠浓度增加。这种增加可以引起高再现性。在激发肌肉组织之前和之后进行测量，以评估使用所开发的方法可视化细胞内钠含量增加的潜力。

项目成果

7-T (35)Cl and (23)Na MR Imaging for Detection of Mutation-dependent Alterations in Muscular Edema and Fat Fraction with Sodium and Chloride Concentrations in Muscular Periodic Paralyses.

7-T (35)Cl 和 (23)Na MR 成像用于检测肌肉周期性麻痹中钠和氯浓度引起的肌肉水肿和脂肪分数的突变依赖性变化

• DOI: 10.1148/radiol.2016151617
• 发表时间: 2016
• 期刊: Radiology
• 影响因子: 19.7
• 作者: Weber MA;Nagel AM;Marschar AM;Glemser P;Jurkat-Rott K;Wolf MB;Ladd ME;Schlemmer HP;Kauczor HU;Lehmann-Horn F
• 通讯作者: Lehmann-Horn F

Partial volume correction for in vivo 23Na-MRI data of the human brain

• DOI: 10.1016/j.neuroimage.2015.03.025
• 发表时间: 2015-05-15
• 期刊: NEUROIMAGE
• 影响因子: 5.7
• 作者: Niesporek, Sebastian C.;Hoffmann, Stefan H.;Nagel, Armin M.
• 通讯作者: Nagel, Armin M.