HIGH FIELD CURRENT DENSITY IMAGING

高场电流密度成像

• 批准号: 7369589
• 负责人: ROSALIND J SADLEIR
• 金额: $ 0.58万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7369589
• 关键词: FIELD; CURRENT; DENSITY; IMAGING

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. When we inject current into an electrically conducting subject such as the human body, it induces voltage, current density, and magnetic flux density distributions. These distributions are determined by the geometry, electrode configuration, and conductivity distribution of the subject. Information about the conductivity and current density distribution is of significant importance in many biomedical applications, such as modeling of tissues in bioelectricity, estimation of current distributions during electrical stimulations, monitoring of physiological functions, lesion detections, and so on. Conductivity image reconstruction has been the active research goal of Electrical Impedance Tomography (EIT) since early 1980s. EIT utilizes the measured current-voltage data on the boundary to provide cross-sectional images of a conductivity distribution. Mathematical analysis of this imaging problem indicates that it has fundamental limitations due to the ill-posed nature of the corresponding inverse problem. Magnetic Resonance Electrical Impedance Tomography (MREIT) has been suggested to overcome this ill-posedness of the image reconstruction problem in EIT. The key idea is to utilize the internal magnetic flux density data measured by an MRI scanner to produce cross-sectional images of conductivity and current density distributions. Lately, several image reconstruction algorithms have been developed based on the measurement of only one component of the magnetic flux density without rotating the subject within the MRI scanner. After discussing the measurement techniques in MREIT, we will present experimental data and reconstructed conductivity and current density images. Summarizing latest outcomes of the MREIT research, we will present future research directions to make MREIT a new clinically applicable conductivity and current density imaging technique.

该子项目是利用 NIH/NCRR 资助的中心拨款提供的资源的众多研究子项目之一。子项目和研究者 (PI) 可能已从另一个 NIH 来源获得主要资金，因此可以在其他 CRISP 条目中得到体现。列出的机构是中心的机构，不一定是研究者的机构。当我们将电流注入人体等导电物体时，它会感应出电压、电流密度和磁通密度分布。这些分布由受试者的几何形状、电极配置和电导率分布决定。有关电导率和电流密度分布的信息在许多生物医学应用中非常重要，例如生物电组织建模、电刺激期间电流分布的估计、生理功能监测、病变检测等。自 20 世纪 80 年代初以来，电导率图像重建一直是电阻抗断层扫描 (EIT) 的积极研究目标。 EIT 利用边界上测量的电流-电压数据来提供电导率分布的横截面图像。该成像问题的数学分析表明，由于相应反问题的不适定性质，它具有根本的局限性。磁共振电阻抗断层扫描 (MREIT) 已被建议用来克服 EIT 中图像重建问题的不适定性。关键思想是利用 MRI 扫描仪测量的内部磁通密度数据来生成电导率和电流密度分布的横截面图像。最近，基于仅测量磁通密度的一个分量而无需在 MRI 扫描仪内旋转对象的情况下，开发了几种图像重建算法。在讨论 MREIT 中的测量技术后，我们将展示实验数据以及重建的电导率和电流密度图像。总结 MREIT 研究的最新成果，我们将提出未来的研究方向，使 MREIT 成为一种新的临床适用的电导率和电流密度成像技术。