GAS EXCHANGE IMAGING IN THE LUNG USING MRI

描述(改编自申请人的摘要)：总体目标 这里提出的是开发和测试磁共振(MR)方法，该方法 允许通过测量气体来评估肺腺泡结构的功能 交换。为了增强信号，该技术使用了激光偏振的(129)Xe。 激光偏振使热(129)Xe的信号增加了1倍 10(4)-10(5)。(129)Xe之所以被选中，是因为它是Xe的十倍以上 可溶于组织中的剩余选择，(3)氦，因为光谱 来自气体的峰和溶解在组织相中的峰之间的间隔为-200/ppm。 这使得这两个阶段的观测都很容易观察到。这个 研究人员建议通过以下方法测量腺泡结构中的气体交换率 观察各谱峰的驰豫恢复率。这个 研究人员建议在组织(溶解)相饱和信号 并观察到由于气体空间的交换而在此阶段产生的信号。 在第一年中，磁共振方法将在模体中优化，然后在大鼠中进行， 其中将使用呼吸机来控制肺容量以确定是否 交换量与肺表面积成正比，这与肺有关。 音量。在人体上的试验将在第二年进行。 肺泡间隔表面是气体交换的部位；其 根据局部表面积与体积的比率进行量化是一个重要的 肺活量的决定因素。这一级别的错乱包括 肺气肿等破坏性疾病的面积减少，以及增厚 肺纤维化等间质性疾病中血/气屏障的研究 和浮肿。临床医学的一个主要缺口是所有现有技术的失败 非侵入性地评估这一重要参数的技术，甚至在 活着。气体交换成像代表了一种全新的潜力 无创性评价肺功能的区域差异。早些时候 检测肺泡表面积的丢失是一种严重的公共卫生问题 迫在眉睫，因为慢性阻塞性肺疾病现在是Th的主导 在美国的死因。

DESCRIPTION (Adapted from the applicant's abstract): The broad objective proposed here is to develop and test a magnetic resonance (MR) method that allows functional evaluation of the lung acinar structures by measuring gas exchange. To enhance the signal, the technique uses laser-polarized (129)Xe. Laser polarization increases the signal over thermal (129)Xe by a factor of 10(4)- 10(5). (129)Xe is chosen because it is more than ten times more soluble in tissue than the remaining choice, (3)He, and because the spectral peaks from the gas and dissolved in tissue phases are separated by -200/ppm. This makes the observation of both phases easily observable. The investigators propose to measure the gas exchange rate in acinar structures by observing the relaxation recovery rate of the spectral peaks. The investigators propose to saturate the signal in the tissue (dissolved) phase and observe the signal in this phase due to exchange from the gas spaces. During the 1st year, MR methods will be optimized in phantoms and then rats, where a ventilator will be used to control the lung volume to determine if the exchange is proportional to the lung surface area, which is related to lung volume. Trial experiments on humans will be performed in the 2nd year. The surface of the alveolar septa is the site of gas exchange; its quantification in terms of the local surface to volume ratio is an important determinant of the efficiency of the lung. Derangements at this level include loss of area in destructive diseases such as emphysema, as well as thickening of the blood/gas barrier in interstitial diseases such as pulmonary fibrosis and edema. A major gap in clinical medicine is the failure of all current techniques to evaluate this important parameter noninvasively, or even in vivo. Gas exchange imaging represents a radically new potential for noninvasive evaluation of regional differences in pulmonary function. Early detection of the loss of alveolar surface area is a serious public health imperative, since chronic obstructive pulmonary disease is now the Th leading cause of death in the US.