Morgan Sherwin E, Kestner John J, Hall Jesse B, Tung Avery
Department of Respiratory Therapy, The University of Chicago Hospitals, 5841 S Maryland Avenue, MC0981, Chicago IL 60637, USA.
Respir Care. 2002 Jan;47(1):61-8.
The unique electromagnetic environment of the magnetic resonance imaging (MRI) scanner presents particular problems for critically ill patients requiring mechanical ventilation during MRI. Most currently available MRI-compatible ventilators are limited in scope and function and thus may not be suitable for patients requiring high peak inspiratory pressure or flow.
To determine whether a standard critical care ventilator could be used under MRI conditions, we modified a Siemens Servo 900C by replacing the standard oxygen blender with an MRI-compatible blender. We then calibrated the ventilator and tested it on a mechanical lung during active MRI scanning at magnetic fields up to 1.5 tesla. After verifying adequate function, we used the ventilator to support 21 critically ill patients requiring mechanical ventilation during MRI.
In all cases we found no alterations in ventilator performance resulting from the electromagnetic interference typical of an MRI scan. We also found no abnormalities in the alarm systems for fraction of inspired oxygen, high inspiratory pressure, or minute volume. Finally, we found no degradation of MRI image quality resulting from ventilator operation during test scanning.
We conclude that with minor modifications the Siemens 900C ventilator can safely ventilate critically ill patients during MRI.
磁共振成像（MRI）扫描仪独特的电磁环境给在MRI检查期间需要机械通气的重症患者带来了特殊问题。目前大多数可用的MRI兼容呼吸机在范围和功能上都有限，因此可能不适用于需要高吸气峰压或流量的患者。
为了确定标准的重症监护呼吸机是否可在MRI条件下使用，我们对西门子Servo 900C呼吸机进行了改装，用MRI兼容的混合器替换了标准的氧气混合器。然后我们对呼吸机进行了校准，并在高达1.5特斯拉磁场的活跃MRI扫描期间在机械肺上对其进行了测试。在验证功能正常后，我们使用该呼吸机为21名在MRI检查期间需要机械通气的重症患者提供支持。
在所有病例中，我们发现MRI扫描典型的电磁干扰未导致呼吸机性能发生改变。我们还发现，在吸入氧分数、高吸气压力或分钟通气量的报警系统中没有异常。最后，我们发现在测试扫描期间呼吸机运行未导致MRI图像质量下降。
我们得出结论，经过 minor modifications，西门子900C呼吸机可在MRI检查期间安全地为重症患者通气。 （注：原文中“minor modifications”未明确具体内容，直译为“小的修改”）
