论文标题
使用关节传输并接收低级张量完成的加速无校准平行传输映射
Accelerated calibrationless parallel transmit mapping using joint transmit and receive low-rank tensor completion
论文作者
论文摘要
目的：评估无校准平行成像的算法，以重建针对身体和大脑的无效的平行传输场图。 方法：使用相对发射图的合成数据，身体和脑测量值，评估了连接传输低量张量完成算法的三种不同方法。这些方法包括：（i）使用接收和传输灵敏度的乘积的虚拟线圈，（ii）联合接收器线圈，该线圈在所有发送模式的接收线圈上强制执行低级结构，以及（iii）低级（TXLR）使用低等级结构的接收模式和同时传输模式。在8通道并行发射7T系统上，研究了不同的噪声水平和不同加速度的性能。 结果：虚拟线圈方法随着噪声水平的升高或加速度大于两个产生的RMS误差大于0.1。联合接收器线圈方法在四个加速度因子上表现良好，超过RMS误差超过0.1。而TXLR启用了八倍的加速度，大多数RMS错误仍低于0.1。 结论：这项工作表明，最多八倍的采样因子对于传输阵列映射是可行的，并且可以使用无校准平行成像方法重建。
Purpose: To evaluate an algorithm for calibrationless parallel imaging to reconstruct undersampled parallel transmit field maps for the body and brain. Methods: Using synthetic data, body, and brain measurements of relative transmit maps, three different approaches to a joint transmit-receive low-rank tensor completion algorithm are evaluated. These methods included: (i) virtual coils using the product of receive and transmit sensitivities, (ii) joint-receiver coils that enforces a low rank structure across receive coils of all transmit modes, and (iii) transmit low rank (TxLR) that uses a low rank structure for both receive and transmit modes simultaneously. The performance of each are investigated for different noise levels and different acceleration rates on an 8-channel parallel transmit 7T system. Results: The virtual coils method broke down with increasing noise levels or acceleration rates greater than two producing RMS error greater than 0.1. The joint receiver coils method worked well up to acceleration factors of four, beyond which the RMS error exceeded 0.1. While TxLR enabled an eight-fold acceleration with most RMS errors remaining below 0.1. Conclusion: This work demonstrates that under-sampling factors of up to eight-fold are feasible for transmit array mapping and can be reconstructed using calibrationless parallel imaging methods.
