DIFFUSION CORRECTED RECONSTRUCTIONS OF PARTIAL PRESSURE OF OXYGEN

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 肺顺应性  定义为每单位压力变化的肺体积变化  是肺力学分析的基本参数之一，了解这一参数对肺部疾病的研究和诊断具有重要意义。 超极化（HP）3 He MRI测量局部氧分压提供了重要的洞察肺功能的生理和病理生理条件下。这源于肺与肺之间的独特相关性的稳态氧分压及其通气/灌注比;肺之间存在类似的关系氧降解率和局部肺泡灌注。 因此，这些措施是极大的兴趣，肺科医生和生理学家。 目前的HP氧测量技术假定在测量周期期间HP气体的扩散对测量的信号强度的影响可忽略不计。 我们表明，在许多条件下，这种假设是错误的，严重降低测量精度，我们提出了第一个直接氧重建算法测量区域氧紧张度的扩散HP造影剂的存在下。 数值模拟和实验结果，以及。

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. Pulmonary compliance  defined as the change in volume of the lung per unit change in pressure  is one of the fundamental parameters used in the analysis of lung mechanics, and knowledge of this parameter is important for the study and diagnosis of pulmonary diseases. Hyperpolarized (HP) 3He MRI measures of regional oxygen tensions provide important insight into lung function under physiologic and pathophysiologic conditions. This stems from the unique correlation between the lungs steady state oxygen tensions and its ventilation perfusion ratios; a similar relationship exists between the lungs the oxygen degradation rate and local alveolar perfusion. Thus these measures are of great interest to pulmonologists and physiologists. Current HP oxygen measurement techniques assume that diffusion of the HP gas during the measurement cycle affects the measured signal intensity negligibly. We show that under many conditions this assumption is false and severely degrades measurement accuracy; we present the first direct oxygen reconstruction algorithm for measuring regional oxygen tensions in the presence of a diffusing HP contrast agent. Numerical simulations and experimental results are presented as well.