GAS EXCHA03NGE IMAGING IN THE LUNG USING MRI

描述（改编自申请人的摘要）：广泛的目标 这里提出的是开发和测试磁共振（MR）方法， 允许通过测量气体来评估肺腺泡结构的功能 交易所 为了增强信号，该技术使用激光偏振（129）偏振。 激光偏振使热（129）散射信号增加了一个因子， 10（4）- 10（5）。 （129）选择“”是因为它是十倍以上 可溶于组织中的剩余选择，（3）He，因为光谱 来自气体的峰和溶解在组织相中的峰相隔-200/ppm。 这使得两个阶段的观察都很容易观察到。 的 研究者建议通过以下方法测量腺泡结构中的气体交换率 观察谱峰的弛豫恢复率。 的 研究者建议在组织（溶解）相中使信号饱和 并观察由于来自气体空间的交换而在该相中的信号。 在第一年，将在幻影和大鼠中优化MR方法， 其中将使用呼吸机来控制肺容量以确定 交换与肺表面积成正比，这与肺 音量. 第二年将进行人体试验。 肺泡隔的表面是气体交换的场所;其 在局部表面与体积比方面的量化是重要的 肺的效率的决定因素。 这一级别的紊乱包括 肺气肿等破坏性疾病的面积损失，以及增厚 肺纤维化等间质性疾病中的血/气屏障 和水肿。 临床医学中的一个主要差距是所有当前的 技术来评估这一重要参数非侵入性，甚至在 vivo.气体交换成像代表了一种全新的潜力， 无创性评估肺功能的区域差异。 早期 检测肺泡表面积的损失是一个严重的公共健康问题 慢性阻塞性肺疾病是目前世界上 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.