An optimal radial profile order based on the golden ratio for time-resolved MRI
An optimal radial profile order based on the golden ratio for time-resolved MRI
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DOI：
10.1109/tmi.2006.885337
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发表时间：
2007-01-01
影响因子：
10.6
通讯作者：
Doessel, Olaf
中科院分区：
文献类型：
--
作者：
Winkelmann, Stefanie;Schaeffter, Tobias;Doessel, Olaf
在动态磁共振成像(MRI)研究中，运动动力学或对比度变异性往往难以预测，这阻碍了图像更新率或时间分辨率的适当选择。研究了基于黄金比的恒定方位向轮廓间距(111.246度)对放射状磁共振成像中任意数目的轮廓图像重建的最优效果。在信噪比(SNR)和伪影水平方面对轮廓顺序进行评估并与均匀轮廓分布进行比较。在健康志愿者的两个应用中，这种配置文件顺序的有利特征得到了例证。首先，将一种先进的滑动窗口重建方案应用于动态心脏成像，重建窗口可以根据可接受的心脏运动程度灵活调整。其次，提出了一种对比度增强的k空间滤波器，它允许从一个原始数据集重建任意时间点的任意数量的图像。该滤波器被用来描述单个反转预脉冲后大脑的T1弛豫。虽然具有恒定角度增量的均匀轮廓分布对于固定和预定数量的轮廓是最佳的，但基于黄金比率的轮廓分布被证明是对于任意数量的轮廓的合适解决方案。
In dynamic magnetic resonance imaging (MRI) studies, the motion kinetics or the contrast variability are often hard to predict, hampering an appropriate choice of the image update rate or the temporal resolution. A constant azimuthal profile spacing (111.246 degrees), based on the Golden Ratio, is investigated as optimal for image reconstruction from an arbitrary number of profiles in radial MRI. The profile order is evaluated and compared with a uniform profile distribution in terms of signal-to-noise ratio (SNR) and artifact level. The favorable characteristics of such a profile order are exemplified in two applications on healthy volunteers. First, an advanced sliding window reconstruction scheme is applied to dynamic cardiac imaging, with a reconstruction window that can be flexibly adjusted according to the extent of cardiac motion that is acceptable. Second, a contrast-enhancing k-space filter is presented that permits reconstructing an arbitrary number of images at arbitrary time points from one raw data set. The filter was utilized to depict the T1-relaxation in the brain after a single inversion prepulse. While a uniform profile distribution with a constant angle increment is optimal for a fixed and predetermined number of profiles, a profile distribution based on the Golden Ratio proved to be an appropriate solution for an arbitrary number of profiles.