Jakob P M, Griswold M A, Edelman R R, Sodickson D K
Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
MAGMA. 1998 Nov;7(1):42-54. doi: 10.1007/BF02592256.
Recently a new fast magnetic resonance imaging strategy, SMASH, has been described, which is based on partially parallel imaging with radiofrequency coil arrays. In this paper, an internal sensitivity calibration technique for the SMASH imaging method using self-calibration signals is described. Coil sensitivity information required for SMASH imaging is obtained during the actual scan using correlations between undersampled SMASH signal data and additionally sampled calibration signals with appropriate offsets in k-space. The advantages of this sensitivity reference method are that no extra coil array sensitivity maps have to be acquired and that it provides coil sensitivity information in areas of highly non-uniform spin-density. This auto-calibrating approach can be easily implemented with only a small sacrifice of the overall time savings afforded by SMASH imaging. The results obtained from phantom imaging experiments and from cardiac studies in nine volunteers indicate that the self-calibrating approach is an effective method to increase the potential and the flexibility of rapid imaging with SMASH.
最近，一种新的快速磁共振成像策略——SMASH被提出，它基于射频线圈阵列的部分并行成像。本文描述了一种使用自校准信号的SMASH成像方法的内部灵敏度校准技术。SMASH成像所需的线圈灵敏度信息是在实际扫描过程中，利用欠采样的SMASH信号数据与在k空间中具有适当偏移的额外采样校准信号之间的相关性获得的。这种灵敏度参考方法的优点是无需额外采集线圈阵列灵敏度图，并且它能在自旋密度高度不均匀的区域提供线圈灵敏度信息。这种自动校准方法只需少量牺牲SMASH成像所节省的总时间就可轻松实现。从模型成像实验和对9名志愿者的心脏研究中获得的结果表明，自校准方法是一种有效提高SMASH快速成像潜力和灵活性的方法。
