Time-varying magnetic field gradients involved in magnetic resonance examinations can damage implanted electronic systems. The quantity related to this side effect is the gradient slew rate, which is usually not directly available on magnetic resonance console. The present study proposes a low-cost approach in slew rate assessment, which is useful in risks versus benefits evaluation as well as in sequences optimization. The experimental method is based on an analog circuit, which senses the output voltage of the scanner waveform generator. This allows taking easy and reliable slew rate measurements, even during clinical examinations on patients. Whereas previous studies required managing a considerable amount of data, the present work addresses only the maximal slew rate of any clinical sequence. Experimental results show that the smooth gradient mode, selectable on the two scanners examined, is very effective in patient safety improvement. In particular, it reduces slew rate values in the range from 52.4 up to 132.4 T m-1 s-1 , i.e. far below the interval 216-346 T m-1 s-1 , indicated as slew rate tolerance limit of modern implanted electronic devices. Bioelectromagnetics. 2019;40:512-521. © 2019 Bioelectromagnetics Society.

中文翻译：

---

植入有源设备的患者的磁共振检查。摆率评估中的低成本方法。

磁共振检查中涉及的随时间变化的磁场梯度可能会损坏植入的电子系统。与此相关的副作用是梯度摆率，通常在磁共振控制台上不能直接获得。本研究提出了一种转换率评估的低成本方法，该方法可用于风险与收益评估以及序列优化。实验方法基于模拟电路，该电路可感测扫描仪波形发生器的输出电压。这样，即使在对患者进行临床检查时，也可以轻松，可靠地测量压摆率。尽管先前的研究需要管理大量数据，但当前的工作仅解决了任何临床序列的最大摆率。实验结果表明，可以在两个检查的扫描仪上选择的平滑梯度模式在提高患者安全性方面非常有效。特别是，它将压摆率值减小到从52.4到132.4 T m-1 s-1的范围，即远低于间隔216-346 T m-1 s-1，表示为现代植入式电子产品的压摆率公差极限设备。生物电磁学。2019; 40：512-521。©2019生物电磁学会。