公开(公告)号：US20060091881A1

公开(公告)日：2006-05-04

申请号：US10980984

申请日：2004-11-03

申请人： John Clarke ,  Nathan Kelso ,  SeungKyun Lee ,  Michael Moessle ,  Whittier Myers ,  Robert McDermott ,  Bernard Haken ,  Alexander Pines ,  Andreas Trabesinger

发明人： John Clarke ,  Nathan Kelso ,  SeungKyun Lee ,  Michael Moessle ,  Whittier Myers ,  Robert McDermott ,  Bernard Haken ,  Alexander Pines ,  Andreas Trabesinger

IPC分类号： G01V3/00

CPC分类号： G01R33/326

摘要： Nuclear magnetic resonance (NMR) signals are detected in microtesla fields. Prepolarization in millitesla fields is followed by detection with an untuned dc superconducting quantum interference device (SQUID) magnetometer. Because the sensitivity of the SQUID is frequency independent, both signal-to-noise ratio (SNR) and spectral resolution are enhanced by detecting the NMR signal in extremely low magnetic fields, where the NMR lines become very narrow even for grossly inhomogeneous measurement fields. Additional signal to noise benefits are obtained by use of a low noise polarization coil, comprising litz wire or superconducting materials. MRI in ultralow magnetic field is based on the NMR at ultralow fields. Gradient magnetic fields are applied, and images are constructed from the detected NMR signals.

摘要翻译： 核磁共振（NMR）信号在微量场中检测。 随后用毫米级直流超导量子干涉仪（SQUID）磁力计检测millitesla场的预偏振。 由于SQUID的灵敏度是频率无关的，所以通过检测极低磁场中的NMR信号来提高信噪比（SNR）和光谱分辨率，即使对于非常不均匀的测量场，NMR线也变得非常窄。 通过使用包含绞合线或超导材料的低噪声极化线圈可以获得额外的噪声有益效果。 超低磁场中的MRI是基于超低场的NMR。 应用梯度磁场，并根据检测到的NMR信号构建图像。