Imaging alveolar-capillary gas transfer using hyperpolarized 129Xe MRI
Imaging alveolar-capillary gas transfer using hyperpolarized 129Xe MRI
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DOI：
10.1073/pnas.0608458103
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发表时间：
2006-11-28
影响因子：
11.1
通讯作者：
Johnson, G. Allan
中科院分区：
文献类型：
--
作者：
Driehuys, Bastiaan;Cofer, Gary P.;Johnson, G. Allan
有效的肺部气体交换依赖于气体穿过将空气空间与毛细血管红细胞（RBC）分开的薄组织屏障的自由扩散。肺部病变，如炎症、纤维化和水肿，会导致血气屏障厚度增加，损害这种交换的效率。然而，这种气体交换异常的明确评估是具有挑战性的，因为目前还没有方法直接成像的气体转移过程。在这里，我们利用的溶解度和化学位移的α-129，其磁共振信号已被增强了10（5）与超极化，差分成像其转移从空气空间到组织屏障空间和红细胞在肺的气体交换区域。基于一个简单的扩散模型，我们估计，这种磁共振成像方法测量的肺泡-毛细血管转移是敏感的血气屏障厚度的变化约5 μ m。我们验证了组织屏障和RBC图像的成功分离，并显示了该方法在肺纤维化大鼠模型中的实用性，其中RBC的IFN-129补充在肺损伤区域中严重受损。
Effective pulmonary gas exchange relies on the free diffusion of gases across the thin tissue barrier separating airspace from the capillary red blood cells (RBCs). Pulmonary pathologies, such as inflammation, fibrosis, and edema, which cause an increased blood-gas barrier thickness, impair the efficiency of this exchange. However, definitive assessment of such gas-exchange abnormalities is challenging, because no methods currently exist to directly image the gas transfer process. Here we exploit the solubility and chemical shift of Xe-129, the magnetic resonance signal of which has been enhanced by 10(5) with hyperpolarization, to differentially image its transfer from the airspaces into the tissue barrier spaces and RBCs in the gas exchange regions of the lung. Based on a simple diffusion model, we estimate that this MR imaging method for measuring Xe-129 alveolar-capillary transfer is sensitive to changes in blood-gas barrier thickness of approximate to 5 mu m. We validate the successful separation of tissue barrier and RBC images and show the utility of this method in a rat model of pulmonary fibrosis where Xe-129 replenishment of the RBCs is severely impaired in regions of lung injury.