| 摘要 |
<p>@ A method for rapid acquisition of NMR data utilizes excitation pulses which rotate the longitudinal magnetization through an angle smaller than 90° to create a relatively large transverse magnetization component. A first 180° RF pulse is then applied to create a spin-echo signal, while a second 180° RF pulse is used to rapidly return to equilibrium the residual longitudinal magnetization inverted by the first pulse. The combination of the excitation and the second 180° pulses permits the sequence repetition time to be shortened, thereby reducing the total data collection time. The method is applicable to, for example, two- and three-dimensional embodiments of Fourier transform and multiple-angle projection reconstruction NMR imaging methods.</p> |
