Advanced Source Reconstruction Techniques for Fetal Magnetocardiography

胎儿心磁图的先进源重建技术

• 批准号: 7694284
• 负责人: MIHAI POPESCU
• 金额: $ 18.66万
• 依托单位: UNIVERSITY OF KANSAS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-30 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7694284
• 关键词: Abdomen; Accounting; Affect; Algorithms; Anatomy; Boundary Elements; Cardiac; Clinical; Clinical Management; Congenital Heart Defects; Congestive Heart Failure; Data; Databases; Defect; Detection; Development; Diabetes Mellitus; Drug Formulations; Ductus Arteriosus; Early Diagnosis; Effectiveness; Electrocardiogram; Electromagnetics; Electrophysiology (science); Environmental Risk Factor; Evaluation; Fetal Growth Retardation; Fetal Heart; Fetus; Future; Gestational Age; Growth; Hand; Heart; Heart Hypertrophy; Individual; Intervention; Investigation; Labor Presentation; Liquid substance; Live Birth; Location; Long QT Syndrome; Longitudinal Studies; Measures; Methodology; Methods; Metric; Modality; Modeling; Monitor; Morphology; Myocardial; Organ; Pathologic; Pattern; Physiology; Positioning Attribute; Pregnancy; Property; Public Health; Pulmonary valve structure; Relative (related person); Risk; Role; Scanning; Screening procedure; Signal Transduction; Solutions; Source; Stenosis; Structure; Supraventricular tachycardia; System; Techniques; Testing; Tetralogy of Fallot; Thick; Third Pregnancy Trimester; Time; Tissues; Translating; Ultrasonography; Validation; Variant; Ventricular; Ventricular Septal Defects; Vernix Caseosa; Work; base; clinical application; clinically significant; cohort; congenital heart disorder; fetal; heart electrical activity; improved; in utero; magnetic field; public health relevance; reconstruction; sensor; spatiotemporal; tool; vector; ventricular hypertrophy

DESCRIPTION (provided by applicant): The early detection of congenital heart anomalies is critical for monitoring or prompt interventions, which can reduce the risks of congestive heart failure. This calls for sustained efforts to improve the existing tools and methodologies used for the non-invasive screening of the fetal heart structure and physiology. Recently, fetal magnetocardiography (fMCG) has emerged as an attractive technique for the in-utero assessment of the fetal cardiac electrophysiology, which can offer vastly superior capabilities to those, attainable by alternative methods. However, a significant concern consists in the large variability in position and orientation of the fetuses relative to the biomagnetic sensing system, which may introduce confounding effects on the morphology of the signals recorded over the maternal abdomen. The paucity of data on detailed fMCG signal morphology is a direct consequence of these confounds, since it is often difficult to explain the intersubject variations in signal distribution across the sensor array as being generated by fundamental differences in the cardiac electrophysiology, common inconsistencies in the fetal presentation or variable anatomy of the fetal- maternal unit. The current study will focus on the development of new strategies for augmenting the clinical utility the fMCG recordings, aiming at examining the cardiac activity in source space (rather than sensor space), where the above described physical factors become non-salient. The proposed approach relies on estimating the spatio temporal parameters of a multi-dipolar model of the fetal cardiac source using a recursive subspace scanning algorithm. To account for the geometry and conductivity properties of the feto-abdominal tissues, the study seeks establishing a versatile strategy for incorporating 3D anatomical information about the feto-abdominal volume conductor obtained from free-hand ultrasound images into the discrete formulation of the forward electromagnetic problem based on boundary element methods. The study will initiate the development of a longitudinal normative data-base for metrics derived from the reconstructed cardiac vectors in fMCG recordings of low-risk pregnancies. Fetal subjects with abnormal increase in the thickness of the free ventricular walls documented by ultrasound will also be studied to probe the sensitivity of the proposed approach for detecting hallmarks of abnormal heart electrophysiology. The investigation aims to represent a substantial contribution in promoting the role of fMCG for the non- invasive screening of fetal cardiac development and for the detection of electrophysiological abnormalities. The successful clinical validation of the methodology will highly recommend fMCG as an investigational tool for studying fetal cardiac electrophysiology in a broad range of conditions, particularly those associated with increased risk of ventricular hypertrophy, e.g. intra-uterine growth retardation, diabetes, pulmonary valve and aortic stenosis, closure of the ductus arteriosus, tetralogy of Fallot, or ventricular septal defect. PUBLIC HEALTH RELEVANCE: Congenital heart anomalies are more common than anomalies affecting any other organ; therefore, further advancement of the techniques used for fetal heart monitoring is likely to have a substantial impact upon public health. Fetal magnetocardiography (fMCG) offers unique capabilities for non-invasive screening of fetal cardiac electrophysiology; however, in order to attain clinical significance, fMCG must provide unequivocal and consistent measures of fetal cardiac activity. This investigation aims to represent a substantial contribution in promoting the role of fMCG for studying fetal cardiac development and electrophysiological abnormalities by means of advanced source reconstruction algorithms, which efficiently use the multichannel fMCG data and 3D ultrasound images of the feto-abdominal anatomy to provide reliable measures of fetal cardiac electrophysiology. The successful clinical validation of the methodology for fetuses with abnormal increase in ventricular wall thickness will highly recommend fMCG as an investigational tool for studying fetal cardiac electrophysiology in a broad range of conditions associated with increased risk of ventricular hypertrophy, e.g. intra-uterine growth retardation, diabetes, pulmonary valve and aortic stenosis, closure of the ductus arteriosus, tetralogy of Fallot, or ventricular septal defect.

描述（由申请人提供）：早期发现先天性心脏异常对于监测或及时干预至关重要，这可以降低充血性心力衰竭的风险。这需要持续努力，以改进现有的工具和方法，用于胎儿心脏结构和生理的非侵入性筛查。最近，胎儿心脏磁图（fMCG）已经成为一种有吸引力的技术，用于子宫内胎儿心脏电生理评估，它可以提供比其他方法更优越的能力。然而，一个值得关注的问题是，相对于生物磁传感系统，胎儿的位置和方向存在很大的可变性，这可能会对母体腹部记录的信号形态产生混淆效应。这些混乱直接导致了fMCG信号形态细节数据的缺乏，因为通常很难将传感器阵列上信号分布的主体间差异解释为心脏电生理的根本差异、胎儿表现的普遍不一致或胎儿-母体单位的不同解剖结构。目前的研究将侧重于开发新的策略，以增加临床应用的fMCG记录，旨在检查源空间（而不是传感器空间）的心脏活动，其中上述物理因素变得不突出。提出的方法依赖于使用递归子空间扫描算法估计胎儿心源的多偶极模型的时空参数。为了解释胎儿-腹部组织的几何和电导率特性，该研究寻求建立一种通用策略，将从徒手超声图像中获得的胎儿-腹部体积导体的三维解剖信息纳入基于边界元方法的正演电磁问题的离散公式中。该研究将启动一个纵向规范数据库的开发，该数据库来源于低风险妊娠的fMCG记录中重建的心脏载体。超声记录的自由心室壁厚度异常增加的胎儿受试者也将被研究，以探测所提出的检测异常心脏电生理标志的方法的敏感性。该研究的目的是在促进fMCG在胎儿心脏发育的非侵入性筛查和电生理异常检测中的作用方面做出实质性贡献。该方法的成功临床验证将强烈推荐fMCG作为广泛条件下研究胎儿心脏电生理的研究工具，特别是那些与心室肥厚风险增加相关的情况，例如子宫内生长迟缓、糖尿病、肺动脉瓣和主动脉狭窄、动脉导管关闭、法洛四联症或室间隔缺损。公共卫生相关性：先天性心脏异常比影响任何其他器官的异常更常见；因此，用于胎儿心脏监测的技术的进一步发展可能对公众健康产生重大影响。胎儿心脏磁图（fMCG）为胎儿心脏电生理的无创筛查提供了独特的能力；然而，为了获得临床意义，fMCG必须提供胎儿心脏活动的明确和一致的措施。本研究旨在通过先进的源重构算法，促进fMCG在研究胎儿心脏发育和电生理异常方面的作用，该算法有效地利用胎儿腹部解剖的多通道fMCG数据和3D超声图像，提供可靠的胎儿心脏电生理测量。对于心室壁厚度异常增加的胎儿，该方法的成功临床验证将强烈推荐fMCG作为研究与心室肥厚风险增加相关的广泛条件下胎儿心脏电生理的研究工具，例如子宫内生长迟缓、糖尿病、肺动脉瓣和主动脉瓣狭窄、动脉导管关闭、法洛四联症或室间隔缺损。