Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA.
Magn Reson Med. 2013 Mar 1;69(3):839-44. doi: 10.1002/mrm.24303. Epub 2012 May 3.
Three-dimensional cardiac magnetic resonance perfusion imaging is promising for the precise sizing of defects and for providing high perfusion contrast, but remains an experimental approach primarily due to the need for large-dimensional encoding, which, for traditional 3DFT imaging, requires either impractical acceleration factors or sacrifices in spatial resolution. We demonstrated the feasibility of rapid three-dimensional cardiac magnetic resonance perfusion imaging using a stack-of-spirals acquisition accelerated by non-Cartesian k-t SENSE, which enables entire myocardial coverage with an in-plane resolution of 2.4 mm. The optimal undersampling pattern was used to achieve the largest separation between true and aliased signals, which is a prerequisite for k-t SENSE reconstruction. Flip angle and saturation recovery time were chosen to ensure negligible magnetization variation during the transient data acquisition. We compared the proposed three-dimensional perfusion method with the standard 2DFT approach by consecutively acquiring both data during each R-R interval in cardiac patients. The mean and standard deviation of the correlation coefficients between time intensity curves of three-dimensional versus 2DFT were 0.94 and 0.06 across seven subjects. The linear correlation between the two sets of upslope values was significant (r = 0.78, P < 0.05).
三维心脏磁共振灌注成像是一种很有前途的技术,可以精确测量缺损的大小,并提供高灌注对比度,但由于需要大尺寸编码,因此仍然是一种实验方法,这对于传统的 3DFT 成像来说,要么需要不切实际的加速因子,要么需要牺牲空间分辨率。我们使用非笛卡尔 k-t SENSE 加速的螺旋堆栈采集方法证明了快速三维心脏磁共振灌注成像的可行性,该方法可以实现整个心肌的覆盖,并且在平面内分辨率为 2.4mm。使用最佳的欠采样模式来实现真实信号和混叠信号之间的最大分离,这是 k-t SENSE 重建的前提条件。翻转角和饱和恢复时间的选择是为了确保在短暂的数据采集过程中磁化强度变化可以忽略不计。我们通过在每个心动周期内连续采集两种数据,比较了提出的三维灌注方法和标准的 2DFT 方法。七个受试者的三维和二维时间强度曲线之间的相关系数的平均值和标准差分别为 0.94 和 0.06。两组斜率值之间存在显著的线性相关性(r = 0.78, P < 0.05)。