Department of Anaesthesiology, Johannes Gutenburg-University, Langenbeckstrasse 1, Mainz, Germany.
Acta Anaesthesiol Scand. 2009 Nov;53(10):1310-6. doi: 10.1111/j.1399-6576.2009.02069.x. Epub 2009 Aug 13.
In the acute respiratory distress syndrome potentially recruitable lung volume is currently discussed. (3)He-magnetic resonance imaging ((3)He-MRI) offers the possibility to visualize alveolar recruitment directly.
With the approval of the state animal care committee, unilateral lung damage was induced in seven anesthetized pigs by saline lavage of the right lungs. The left lung served as an intraindividual control (healthy lung). Unilateral lung damage was confirmed by conventional proton MRI and spiral-CT scanning. The total aerated lung volume was determined both at a positive end-expiratory pressure (PEEP) of 0 and 10 mbar from three-dimensionally reconstructed (3)He images, both for healthy and damaged lungs. The fractional increase of aerated volume in damaged and healthy lungs, followed by a PEEP increase from 0 to 10 mbar, was compared.
Aerated gas space was visualized with a high spatial resolution in the three-dimensionally reconstructed (3)He-MR images, and aeration defects in the lavaged lung matched the regional distribution of atelectasis in proton MRI. After recruitment and PEEP increase, the aerated volume increased significantly both in healthy lungs from 415 ml [270-445] (median [min-max]) to 481 ml [347-523] and in lavaged lungs from 264 ml [71-424] to 424 ml [129-520]. The fractional increase in lavaged lungs was significantly larger than that in healthy lungs (healthy: 17% [11-38] vs. lavage: 42% [14-90] (P=0.031).
The (3)He-MRI signal might offer an experimental approach to discriminate atelectatic vs. poor aerated lung areas in a lung damage animal model. Our results confirm the presence of potential recruitable lung volume by either alveolar collapse or alveolar flooding, in accordance with previous reports by computed tomography.
在急性呼吸窘迫综合征中，目前正在讨论潜在可复张的肺容积。（3）氦磁共振成像（（3）He-MRI）提供了直接可视化肺泡复张的可能性。
在获得国家动物护理委员会的批准后，通过对右侧肺进行盐水灌洗，在 7 只麻醉猪中诱导单侧肺损伤。左侧肺作为个体内对照（健康肺）。通过常规质子 MRI 和螺旋 CT 扫描确认单侧肺损伤。通过三维重建（3）He 图像，在呼气末正压（PEEP）为 0 和 10 mbar 时，分别确定健康和受损肺的总充气肺容积。比较 PEEP 从 0 增加到 10 mbar 时，健康和受损肺充气量的分数增加。
三维重建（3）He-MRI 图像可高空间分辨率可视化充气气体空间，灌洗肺中的充气缺陷与质子 MRI 中的区域性肺不张分布相匹配。在招募和 PEEP 增加后，健康肺的充气量从 415 ml [270-445]（中位数[最小-最大]）显著增加到 481 ml [347-523]，灌洗肺从 264 ml [71-424]显著增加到 424 ml [129-520]。灌洗肺的充气量增加分数明显大于健康肺（健康肺：17% [11-38] vs. 灌洗肺：42% [14-90]（P=0.031）。
（3）He-MRI 信号可能为区分肺损伤动物模型中肺不张与充气不良的肺区提供一种实验方法。我们的结果证实了肺泡塌陷或肺泡积水导致潜在可复张肺容积的存在，这与之前的 CT 报告一致。
