Wendt R E, Rokey R, Vick G W, Johnston D L
Department of Radiology, Baylor College of Medicine, Houston, Texas 77030.
Magn Reson Imaging. 1988;6(1):89-95. doi: 10.1016/0730-725x(88)90528-0.
ECG gating and monitoring during NMR imaging may be achieved reliably by applying the principles in this tutorial. In order to use the ECG signal both for triggering and for patient monitoring it must have a prominent R-wave, while at the same time must have little artifact from gradient switches or the Lorentz voltage across the aorta, and not be significantly distorted by gradient switching artifacts. The twin goals of no image artifacts and minimal ECG artifacts may be achieved by the following means: (1) using ECG electrodes with minimal metal, (2) selecting electrodes and cables with no ferrous metals, (3) placing the limb electrodes close together, (4) placing the line between the limb electrodes and the leg electrode parallel to the magnetic flux lines and, if possible, parallel to the transverse component of the gradient flux lines, (5) keeping the area between the limb electrodes and the leg electrode small, (6) placing that area in the center of the imager and (7) twisting or braiding the cables. Following these principles allows artifact-free images and reliable ECG monitoring during ECG-gated NMR imaging examinations.
在核磁共振成像期间，通过应用本教程中的原理可以可靠地实现心电图门控和监测。为了将心电图信号用于触发和患者监测，它必须有明显的R波，同时必须几乎没有来自梯度切换或主动脉上洛伦兹电压的伪影，并且不会因梯度切换伪影而显著失真。可以通过以下方法实现无图像伪影和最小心电图伪影这两个目标：（1）使用金属最少的心电图电极；（2）选择无铁金属的电极和电缆；（3）将肢体电极靠近放置；（4）将肢体电极与腿部电极之间的连线平行于磁力线，并且如果可能的话，平行于梯度通量线的横向分量；（5）保持肢体电极与腿部电极之间的面积小；（6）将该区域放置在成像仪的中心；（7）将电缆绞合或编织。遵循这些原则可在心电图门控核磁共振成像检查期间获得无伪影的图像和可靠的心电图监测。
