Biomedical and Metabolic Imaging Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA.
Magn Reson Med. 2012 Sep;68(3):822-9. doi: 10.1002/mrm.23305. Epub 2011 Dec 9.
Black-blood fast spin-echo imaging is a powerful technique for the evaluation of cardiac anatomy. To avoid fold-over artifacts, using a sufficiently large field of view in phase-encoding direction is mandatory. The related oversampling affects scanning time and respiratory chest motion artifacts are commonly observed. The excitation of a volume that exclusively includes the heart without its surrounding structures may help to improve scan efficiency and minimize motion artifacts. Therefore, and by building on previously reported inner-volume approach, the combination of a black-blood fast spin-echo sequence with a two-dimensionally selective radiofrequency pulse is proposed for selective "local excitation" small field of view imaging of the heart. This local excitation technique has been developed, implemented, and tested in phantoms and in vivo. With this method, small field of view imaging of a user-specified region in the human thorax is feasible, scanning becomes more time efficient, motion artifacts can be minimized, and additional flexibility in the choice of imaging parameters can be exploited.
黑血快速自旋回波成像是评估心脏解剖结构的强大技术。为了避免折叠伪影，在相位编码方向上使用足够大的视野是强制性的。相关的过采样会影响扫描时间，并且经常观察到呼吸胸部运动伪影。激发仅包括心脏而不包括其周围结构的体积可能有助于提高扫描效率并最小化运动伪影。因此，基于之前报道的内部体积方法，提出了一种结合黑血快速自旋回波序列和二维选择性射频脉冲的方法，用于心脏的选择性“局部激发”小视野成像。该局部激发技术已在体模和体内进行了开发、实现和测试。使用这种方法，可以对人体胸部的用户指定区域进行小视野成像，扫描变得更有效率，运动伪影可以最小化，并且可以在成像参数的选择方面具有更大的灵活性。
