THE NMR PHASED-ARRAY
THE NMR PHASED-ARRAY
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DOI：
10.1002/mrm.1910160203
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发表时间：
1990-11-01
影响因子：
3.3
通讯作者：
MUELLER, OM
中科院分区：
文献类型：
--
作者：
ROEMER, PB;EDELSTEIN, WA;MUELLER, OM
我们描述了同时获取并随后结合来自众多紧密位置NMR接收线圈的数据的方法。该方法在概念上类似于阶段阵列雷达和超声波，因此我们将技术称为“ NMR分阶段阵列”。 NMR分阶段阵列提供了信号噪声比（SNR）和通常与身体成像相关的视场（FOV）的小表面线圈的分辨率，而成像时间没有增加。对于所有脉冲序列，NMR分阶段阵列都可以应用于成像和光谱。 （a）通过重叠相邻的线圈来消除附近表面线圈之间的有问题的相互作用，从而产生零相互感应，因此相互作用为零，以及（b）将低输入障碍前置放大器连接到所有线圈上。我们得出了一种算法，用于结合从分阶段阵列元素的数据，以产生最佳SNR的图像。探索了其他以较低SNR为代价实施的技术。用高分辨率（512。时间512、48厘米FOV和32厘米FOV）的胸腔和腰椎图像证明了分阶段阵列成像。数据是从四元素线性脊柱阵列中获取的，第一个由12厘米方形线圈和第二个正方形线圈制成。与单个15时的图像相比。 30厘米矩形线圈和相同的成像参数，分阶段的阵列产生2。时间。 3次。脊柱深度（.apprx。7厘米）处的SNR较高。
We describe methods for simultaneously acquiring and subsequently combining data from a multitude of closely positioned NMR receiving coils. The approach is conceptually similar to phased array radar and ultrasound and hence we call our techiques the "NMR phased array". The NMR phased array offers the signal-to-noise ratio (SNR) and resolution of a small surface coil over fields-of-view (FOV) normally associated with body imaging with no increase in imaging time. The NMR phased array can be applied to both imaging and spectroscopy for all pulse sequences. The problematic interactions among nearby surface coils is eliminated (a) by overlapping adjacent coils to give zero mutual inductance, hence zero interaction, and (b) by attaching low input impedance preamplifiers to all coils, thus eliminating interference among next nearest and more distant neighbors. We derive an algorithm for combining the data from the phased array elements to yield an image with optimum SNR. Other techniques which are easier to implement at the cost of lower SNR are explored. Phased array imaging is demonstrated with high resolution (512 .times. 512, 48-cm FOV, and 32-cm FOV) spin-echo images of the thoracic and lumbar spine. Data were acquired from four-element linear spine arrays, the first made of 12-cm square coils and the second made of 8-cm square coils. When compared with images from a single 15 .times. 30-cm rectangular coil and identical imaging parameters, the phased array yields a 2 .times. 3 .times. higher SNR at the depth of the spine (.apprx. 7 cm).