Department of Radiology, Johannes Gutenberg-University, Mainz, Germany.
Magn Reson Med. 2010 Nov;64(5):1478-83. doi: 10.1002/mrm.22528.
High-frequency oscillatory ventilation is looked upon as a lung-protective ventilation strategy. For a further clarification of the physical processes promoting gas transport, a visualization of gas flow and the distribution of ventilation are of considerable interest. Therefore, fluorine-19 magnetic resonance imaging of the imaging gas octafluorocyclobutane (C(4) F(8) ) during high-frequency oscillatory ventilation was performed in five healthy pigs. For that, a mutually compatible ventilation-imaging system was set up and transverse images were acquired every 5 sec using FLASH sequences on a 1.5 T scanner. Despite a drop in signal-to-noise ratio after the onset of high-frequency oscillatory ventilation, for each pig, the four experiments could be analyzed. A mean wash-out time (τ) at 5 Hz of 52.7 ± 18 sec and 125.9 ± 39 sec at 10 Hz, respectively, were found for regions of interest including the whole lung. This is in agreement with the clinical findings, in that wash-out of respiratory gases is significantly prolonged for increased high-frequency oscillatory ventilation frequencies. Our study could be a good starting-point for a further optimization of high-frequency oscillatory ventilation.
高频振荡通气被视为一种肺保护通气策略。为了进一步澄清促进气体传输的物理过程，对气体流动和通气分布进行可视化具有重要意义。因此，在五头健康猪中进行了高频振荡通气时成像气体八氟环丁烷（C（4）F（8））的氟-19 磁共振成像。为此，建立了一个相互兼容的通气-成像系统，并在 1.5 T 扫描仪上使用 FLASH 序列每 5 秒采集一次横断面图像。尽管高频振荡通气开始后信噪比下降，但对于每头猪，都可以分析四个实验。包括整个肺在内的感兴趣区域的平均清除时间（τ）分别为 5 Hz 时为 52.7 ± 18 秒和 10 Hz 时为 125.9 ± 39 秒。这与临床发现一致，即高频振荡通气频率增加会导致呼吸气体的清除时间显著延长。我们的研究可以为进一步优化高频振荡通气提供一个良好的起点。
