Quantitative evaluation of pulmonary gas-exchange function using hyperpolarized 129Xe CEST MRS and MRI
Quantitative evaluation of pulmonary gas-exchange function using hyperpolarized 129Xe CEST MRS and MRI
复制标题
使用超极化 129Xe CEST MRS 和 MRI 定量评估肺气体交换功能
DOI：
10.1002/nbm.3961
复制
发表时间：
2018-09-01
影响因子：
2.9
通讯作者：
Zhou, Xin
中科院分区：
文献类型：
--
作者：
Li, Haidong;Zhang, Zhiying;Zhou, Xin
超极化Xe-129气体MR由于自旋极化的极高增强、在肺实质中良好的溶解性以及对其周围环境优异的化学敏感性，已成为评估肺结构和功能的有力工具。通常，通过采用化学位移饱和恢复（CSSR）和氙偏振转移对比（XTC）技术，使用超极化Xe-129来评估肺的定量结构和功能信息。超极化Xe-129化学交换饱和转移（Hyper-CEST）是另一种利用氙信号根据其不同化学位移进行交换来量化超极化Xe-129交换信息的方法，已广泛应用于体外生物传感器研究。然而，使用超极化 Xe-129 CEST 量化体内肺气体交换功能的可行性仍不清楚。在本研究中，CEST 技术分别通过超极化 Xe-129 MRS 和 MRI 定量评估肺部全局和区域的气体交换。定义了一个新参数，肺表观气体交换时间常数 (T-app)，与对照组相比，慢性阻塞性肺病 (COPD) 大鼠（由香烟烟雾和脂多糖暴露引起）从 0.63 秒增加到 0.95 秒，具有显着差异 (P = 0.001)。此外，COPD大鼠肺实质中T-app的空间分布图与健康大鼠相比呈现区域性明显增加。这些结果表明，超极化Xe-129 CEST MR是全球和区域量化肺气体交换功能的有效方法，有助于诊断与气体交换相关的肺部疾病，例如COPD。
Hyperpolarized Xe-129 gas MR has been a powerful tool for evaluating pulmonary structure and function due to the extremely high enhancement in spin polarization, the good solubility in the pulmonary parenchyma, and the excellent chemical sensitivity to its surrounding environment. Generally, the quantitative structural and functional information of the lung are evaluated using hyperpolarized Xe-129 by employing the techniques of chemical shift saturation recovery (CSSR) and xenon polarization transfer contrast (XTC). Hyperpolarized Xe-129 chemical exchange saturation transfer (Hyper-CEST) is another method for quantifying the exchange information of hyperpolarized Xe-129 by using the exchange of xenon signals according to its different chemical shifts, and it has been widely used in biosensor studies in vitro. However, the feasibility of using hyperpolarized Xe-129 CEST to quantify the pulmonary gas exchange function in vivo is still unclear. In this study, the technique of CEST was used to quantitatively evaluate the gas exchange in the lung globally and regionally via hyperpolarized Xe-129 MRS and MRI, respectively. A new parameter, the pulmonary apparent gas exchange time constant (T-app), was defined, and it increased from 0.63s to 0.95s in chronic obstructive pulmonary disease (COPD) rats (induced by cigarette smoke and lipopolysaccharide exposure) versus the controls with a significant difference (P=0.001). Additionally, the spatial distribution maps of T-app in COPD rats' pulmonary parenchyma showed a regionally obvious increase compared with healthy rats. These results indicated that hyperpolarized Xe-129 CEST MR was an effective method for globally and regionally quantifying the pulmonary gas exchange function, which would be helpful in diagnosing lung diseases that are related to gas exchange, such as COPD.