NMR-Based Rapid Fluid Assessment: Device Design and Signal Processing

基于核磁共振的液体快速评估：设备设计和信号处理 项目摘要 我们的目标是开发一种便携式、非侵入式、测量容积状态的方法，以提高质量 降低住院患者的发病率和死亡率。维持正常血容量 状态和适当的液体平衡对于健康和改善肾脏的结果是至关重要的， 心血管疾病和许多其他疾病类型，以及在健康人群中， 脱水，如运动员和士兵。我们的实验室以前建造了一个便携式 能够分辨单个流体的单侧磁共振（MR）传感器 隔室（皮下、肌内等）在组织内。这个传感器被用于一个飞行员 终末期肾病患者的临床试验。这些患者的定量MRI结果 表明血液透析患者液体超负荷的第一个迹象是扩大 骨骼肌细胞外液（ECF）间隙。这项技术的早期性质是 因为便携式传感器不能明确区分骨骼肌 组织从皮下组织。 该研究包括一种新型便携式低场MR传感器的设计， 改进的信号处理，使其能够捕获相同的定量评估， 目前可通过定量MRI（qMRI）实现的容量状态。我们测量局部流体 在靶体内组织区室中的分布。在液体容量状态的情况下， 假设局部骨骼肌测量值代表全身液体 基于先前研究结果的分布1。优化的传感器将具有灵敏的 磁场的区域设计为针对骨骼肌。现有和新 设计的便携式MR传感器将用于测量终末期肌内液体分布 接受透析治疗的肾病患者以及经历透析治疗的健康运动员 运动引起的体液流失。传感器测量将允许量化体积 超负荷（血容量过多）或耗竭（血容量不足），并允许其用于临床决策 制作。透析患者和运动员是以下建议的目标人群。的 在透析期和锻炼期间分别快速减少液体体积提供了 进行重复液体状态测量的理想临床环境。

NMR-Based Rapid Fluid Assessment: Device Design and Signal Processing PROJECT SUMMARY Our goal is to develop a portable, non-invasive, measurement of volume status to improve quality of life and reduce morbidity and mortality among hospitalized patients. Maintenance of euvolemic status and proper fluid balance are critical for health and improved outcomes for renal, cardiovascular, and many other disease types as well as in healthy populations prone to dehydration such as athletes and soldiers. Our laboratory has previously constructed a portable single sided magnetic resonance (MR) sensors that is capable of resolving individual fluid compartments (subcutaneous, intramuscular, etc.) within tissue. This sensor was used in a pilot clinical trial with end stage kidney disease patients. Quantitative MRI results on these patients demonstrated that the first sign of fluid overload among hemodialysis patients is an expanded skeletal muscle extracellular fluid (ECF) space. The early stage nature of the technology was evident in that study as the portable sensor could not unambiguously differentiate skeletal muscle tissue from subcutaneous tissue. The proposed research includes the design of a new portable low-field MR sensor and improved signal processing that will allow it to capture the same quantitative assessment of volume status currently achievable with quantitative MRI (qMRI). We measure local fluid distribution in the target in vivo tissue compartment. In the case of fluid volume status, our hypothesis is that a localized skeletal muscle measurement is representative of systemic fluid distribution based on results from a prior study1. The optimized sensor will have the sensitive region of the magnetic field designed to target the skeletal muscle. The existing and newly designed portable MR sensors will be used to measure intramuscular fluid distribution in end stage kidney disease patients undergoing dialysis treatment as well as in healthy athletes experiencing exercise induced fluid loss. The sensor measurement will allow for quantification of volume overload (hypervolemia) or depletion (hypovolemia) and allow for its use in clinical decision making. Dialysis patients and athletes are the target population for the following proposal. The rapid reduction in fluid volume during a dialysis session and exercise respectively provides the ideal clinical context for performing repeated fluid status measurements.