Direct and accelerated parameter mapping using the unscented Kalman filter.
Direct and accelerated parameter mapping using the unscented Kalman filter.
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DOI：
10.1002/mrm.25796
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发表时间：
2016-05
影响因子：
3.3
通讯作者：
Meyer CH
中科院分区：
文献类型：
--
作者：
Zhao L;Feng X;Meyer CH
为了加速参数映射使用一个新的范例，结合图像重建和模型回归作为一个参数状态跟踪问题。在T2映射中，T2映射首先通过多TE测量在参数空间中编码，然后通过具有读出/相位编码梯度的傅立叶变换编码。利用状态转移函数和测量函数，无迹卡尔曼滤波器可以将T2映射描述为动态系统，并直接从k空间数据估计T2映射。所提出的方法进行了验证与数字脑体模和志愿者实验与多重对比自旋回波序列。它的性能进行了比较，共轭梯度非线性反演方法在欠采样因子为2至8。在此基础上设计了一种加速脉冲序列，实现了预期欠采样。与非线性反演重建方法相比，该方法具有更高的重建精度，提高了结构相似性，降低了归一化均方根误差，在数字体模和志愿者研究中加速因子可达8。这项工作描述了一个新的角度参数映射的状态跟踪。无迹卡尔曼滤波器为T2映射提供了一个高度加速和有效的范例。
To accelerate parameter mapping using a new paradigm that combines image reconstruction and model regression as a parameter state-tracking problem. In T2 mapping, the T2 map is first encoded in parameter space by multi-TE measurements and then encoded by Fourier transformation with readout/phase encoding gradients. Using a state transition function and a measurement function, the unscented Kalman filter can describe T2 mapping as a dynamic system and directly estimate the T2 map from the k-space data. The proposed method was validated with a numerical brain phantom and volunteer experiments with a multiple-contrast spin echo sequence. Its performance was compared to a conjugate-gradient nonlinear inversion method at undersampling factors of 2 to 8. An accelerated pulse sequence was developed based on this method to achieve prospective undersampling. Compared to the nonlinear inversion reconstruction, the proposed method had higher precision, improved structural similarity and reduced normalized root mean squared error, with acceleration factors up to 8 in numerical phantom and volunteer studies. This work describes a new perspective on parameter mapping by state tracking. The unscented Kalman filter provides a highly accelerated and efficient paradigm for T2 mapping.