Academic Radiology, Department of Cardiovascular Science, University of Sheffield, Sheffield, UK.
Sensors (Basel). 2013 Aug 23;13(9):11271-9. doi: 10.3390/s130911271.
We have developed a Magnetic Resonance Imaging (MRI)-compatible system to enable gating of a scanner to the heartbeat of a foetus for cardiac, umbilical cord flow and other possible imaging applications. We performed radiofrequency safety testing prior to a fetal electrocardiogram (fECG) gated imaging study in pregnant volunteers (n = 3). A compact monitoring device with advanced software capable of reliably detecting both the maternal electrocardiogram (mECG) and fECG simultaneously was modified by the manufacturer (Monica Healthcare, Nottingham, UK) to provide an external TTL trigger signal from the detected fECG which could be used to trigger a standard 1.5 T MR (GE Healthcare, Milwaukee, WI, USA) gating system with suitable attenuation. The MR scanner was tested by triggering rapidly during image acquisition at a typical fetal heart rate (123 beats per minute) using a simulated fECG waveform fed into the gating system. Gated MR images were also acquired from volunteers who were attending for a repeat fetal Central Nervous System (CNS) examination using an additional rapid cardiac imaging sequence triggered from the measured fECG. No adverse safety effects were encountered. This is the first time fECG gating has been used with MRI and opens up a range of new possibilities to study a developing foetus.
我们开发了一种磁共振成像（MRI）兼容系统，能够将扫描仪与胎儿的心跳同步，用于心脏、脐带血流和其他可能的成像应用。我们在孕妇志愿者（n=3）中进行了胎儿心电图（fECG）门控成像研究之前的射频安全测试。制造商（英国诺丁汉的 Monica Healthcare）对一款具有可靠检测母亲心电图（mECG）和 fECG 功能的紧凑型监测设备进行了改装，同时添加了先进的软件，该设备能够提供一个来自检测到的 fECG 的外部 TTL 触发信号，可用于触发标准的 1.5 T MR（美国威斯康星州密尔沃基的通用电气医疗系统）门控系统，并具有适当的衰减。该 MR 扫描仪通过使用输入到门控系统中的模拟 fECG 波形在图像采集过程中快速触发进行了测试，典型的胎儿心率为 123 次/分钟。还从接受额外快速心脏成像序列的志愿者那里获取了门控 MR 图像，该序列由测量的 fECG 触发。未发现任何不良安全影响。这是第一次将 fECG 门控技术用于 MRI，为研究发育中的胎儿开辟了一系列新的可能性。
