Lungs Pathology Detection Using Hyperpolarized 129Xe

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DESCRIPTION (provided by applicant): The development of novel hyperpolarized 129Xe nuclear magnetic resonance (NMR) techniques is proposed to non-invasively assess global and regional lung function as well as physiology in-vivo, without the use of radioactive substances or ionizing radiation. It is hypothesized that xenon uptake and exchange dynamics can be reliably detected and exploited to provide pulmonological information that is unobtainable with any other diagnostic modality. In an optimized form these new techniques are expected to become a powerful addition to the arsenal of pulmunologists since they may permit the early detection of pathological changes in the lung parenchyma as well as the study of disease progression and the monitoring of treatment. Once the technologies have been developed they will be tested on an emphysema disease model in rabbits to evaluate whether they provide substantial advantages in the early diagnosis of COPD over existing methods. Although a suggested application is the detection of emphysematous lung the investigated methods will help characterize lung function and increase the sensitivity for lung pathology in general. These goals will be approached in three stages. First, using a series of frequency-selective RF pulses centered at the resonance for 129Xe dissolved in the lung parenchyma the uptake and exchange parameters in rabbits and dogs will be determined. The obtained parameter values are used to optimize xenon-polarization-transfer-contrast magnetic resonance imaging sequences, which can be sensitized to map the surface-to-volume ratio or the lung tissue density. In a second step, the methods will be further refined to distinguish gas exchange between alveoli and tissue from exchange between alveoli and red blood cells. Finally, the performance of the optimized NMR pulse sequence techniques will be evaluated by detecting and monitoring the development of emphysema in a rabbit model.