Department of Medical Physics in Radiology, German Cancer Research Center (dkfz), Heidelberg, Germany.
Magn Reson Med. 2011 Oct;66(4):1109-15. doi: 10.1002/mrm.22871. Epub 2011 Mar 9.
An efficient breathing system was designed for direct (17)O MRI to perform oxygen metabolism studies of the human brain. The breathing system consists of a demand oxygen delivery device for (17)O(2) supply and a custom-built re-breathing circuit with pneumatic switching valve. To efficiently deliver the (17)O gas to the alveoli of the lungs, the system applies short gas pulses upon an inspiration trigger via a nasal cannula. During and after (17)O(2) administration, the exhaled gas volumes are stored and filtered in the re-breathing section to make the most efficient use of the rare (17)O gas. In an inhalation experiment, 2.2 ± 0.1 L of 70%-enriched (17)O(2) were administered to a healthy volunteer and direct (17)O MRI was performed for a total imaging time of 38 min with a temporal resolution of 50 s per 3D data set. Mapping of the maximum signal increase was carried out showing regional variations of oxygen concentration of up to 30% over the natural abundance of (17)O water.
设计了一种高效的呼吸系统，用于直接（17）O MRI 进行人脑氧代谢研究。该呼吸系统由用于（17）O 2 供应的需求氧气输送装置和带有气动开关阀的定制再呼吸回路组成。为了将（17）O 气体有效地输送到肺部的肺泡，该系统通过鼻插管在吸气触发时施加短的气体脉冲。在（17）O 2 给药期间和之后，呼出的气体体积被储存在再呼吸部分中并进行过滤，以最有效地利用稀有的（17）O 气体。在吸入实验中，向健康志愿者给予 2.2 ± 0.1 L 浓度为 70%的（17）O 2，并进行直接（17）O MRI，总成像时间为 38 分钟，每个 3D 数据集的时间分辨率为 50 秒。进行了最大信号增加的映射，显示了氧浓度的区域变化，与（17）O 水的自然丰度相比，氧浓度最高可达 30%。
