BACKGROUND Rapid application of external defibrillation, a crucial first-line therapy for ventricular fibrillation and cardiac arrest, is currently unavailable in the setting of magnetic resonance imaging (MRI), raising concerns about patient safety during MRI tests and MRI-guided procedures, particularly in patients with cardiovascular diseases. The objective of this study was to examine the feasibility and safety of defibrillation/pacing for the entire range of clinically useful shock energies inside the MRI bore and during scans, using defibrillation/pacing outside the magnet as a control. METHODS Experiments were conducted using a commercial defibrillator (LIFEPAK 20, Physio-Control, Redmond, Washington, USA) with a custom high-voltage, twisted-pair cable with two mounted resonant floating radiofrequency traps to reduce emission from the defibrillator and the MRI scanner. A total of 18 high-energy (200-360 J) defibrillation experiments were conducted in six swine on a 1.5 T MRI scanner outside the magnet bore, inside the bore, and during scanning, using adult and pediatric defibrillation pads. Defibrillation was followed by cardiac pacing (with capture) in a subset of two animals. Monitored signals included: high-fidelity temperature (0.01 °C, 10 samples/sec) under the pads and 12-lead electrocardiogram (ECG) using an MRI-compatible ECG system. RESULTS Defibrillation/pacing was successful in all experiments. Temperature was higher during defibrillation inside the bore and during scanning compared with outside the bore, but the differences were small (ΔT: 0.5 and 0.7 °C, p = 0.01 and 0.04, respectively). During scans, temperature after defibrillation tended to be higher for pediatric vs. adult pads (p = 0.08). MR-image quality (signal-to-noise ratio) decreased by ~ 10% when the defibrillator was turned on. CONCLUSIONS Our study demonstrates the feasibility and safety of in-bore defibrillation for the full range of defibrillation energies used in clinical practice, as well as of transcutaneous cardiac pacing inside the MRI bore. Methods for Improving MR-image quality in the presence of a working defibrillator require further study.

中文翻译：

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MRI 期间的高能体外除颤和经皮起搏：可行性和安全性。


背景 外部除颤是治疗心室颤动和心脏骤停的重要一线疗法，但目前在磁共振成像 (MRI) 环境中无法快速应用，这引起了人们对 MRI 测试和 MRI 引导手术期间患者安全的担忧，特别是在患有心血管疾病的患者。本研究的目的是检查 MRI 孔内和扫描期间临床上有用的整个范围的除颤/起搏的可行性和安全性，并使用磁体外部的除颤/起搏作为对照。方法 使用商用除颤器（LIFEPAK 20，Physio-Control，雷蒙德，华盛顿州，美国）进行实验，该除颤器配有定制高压双绞线，并带有两个安装的谐振浮动射频陷阱，以减少除颤器和 MRI 扫描仪的辐射。使用成人和儿童除颤垫，在磁体孔外、孔内以及扫描期间的 1.5 T MRI 扫描仪上，对 6 只猪进行了总共 18 次高能 (200-360 J) 除颤实验。对两只动物进行除颤后进行心脏起搏（带​​捕获）。监测信号包括：电极垫下的高保真温度（0.01 °C，10 个样本/秒）以及使用 MRI 兼容心电图系统的 12 导联心电图 (ECG)。结果 除颤/起搏在所有实验中均成功。与孔外相比，孔内除颤期间和扫描期间的温度较高，但差异很小（ΔT：0.5 和 0.7 °C，分别为 p = 0.01 和 0.04）。在扫描过程中，儿童电极片除颤后的温度往往高于成人电极片 (p = 0.08)。 当除颤器打开时，MR 图像质量（信噪比）下降约 10%。结论 我们的研究证明了临床实践中使用的各种除颤能量的孔内除颤以及 MRI 孔内经皮心脏起搏的可行性和安全性。在除颤器工作的情况下提高 MR 图像质量的方法需要进一步研究。