Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
Magn Reson Med. 2009 Nov;62(5):1211-20. doi: 10.1002/mrm.22114.
Contemporary coronary magnetic resonance angiography techniques suffer from signal-to-noise ratio (SNR) constraints. We propose a method to enhance SNR in gradient echo coronary magnetic resonance angiography by using sensitivity encoding (SENSE). While the use of sensitivity encoding to improve SNR seems counterintuitive, it can be exploited by reducing the number of radiofrequency excitations during the acquisition window while lowering the signal readout bandwidth, therefore improving the radiofrequency receive to radiofrequency transmit duty cycle. Under certain conditions, this leads to improved SNR. The use of sensitivity encoding for improved SNR in three-dimensional coronary magnetic resonance angiography is investigated using numerical simulations and an in vitro and an in vivo study. A maximum 55% SNR enhancement for coronary magnetic resonance angiography was found both in vitro and in vivo, which is well consistent with the numerical simulations. This method is most suitable for spoiled gradient echo coronary magnetic resonance angiography in which a high temporal and spatial resolution is required.
当代冠状动脉磁共振血管造影技术受到信噪比（SNR）的限制。我们提出了一种利用灵敏度编码（SENSE）来提高梯度回波冠状动脉磁共振血管造影 SNR 的方法。虽然利用灵敏度编码来提高 SNR 的想法似乎有违直觉，但通过在采集窗口期间减少射频激发的数量，同时降低信号读出带宽，从而提高射频接收与射频发射的占空比，就可以利用这一方法。在某些条件下，这会导致 SNR 提高。使用灵敏度编码来提高三维冠状动脉磁共振血管造影的 SNR，通过数值模拟以及离体和在体研究进行了研究。在离体和在体研究中均发现冠状动脉磁共振血管造影的 SNR 最高可提高 55%，这与数值模拟结果非常吻合。该方法最适合需要高时间和空间分辨率的扰相梯度回波冠状动脉磁共振血管造影。
