压缩感知磁共振成像脉冲序列的设计与实现

Design and Implementation of Compressed Sensing MRI Pulse Sequence

为了进一步减少数据扫描时间,提高磁共振成像速度,我们对压缩感知MRI脉冲序列进行了研究。采用相位编码方向变密度欠采集的方式,设计了基于自旋回波的压缩感知序列;并采用PPL语言编程,在永磁和超导MR扫描仪上实现了该序列,对压缩感知欠采集与自旋回波全采集的数据进行了图象重建和分析。结果表明:该序列达到了压缩感知的要求,采集的头部和膝盖数据的最佳欠采样加速因子分别为2和4,大大节省了数据采集时间。该序列的实现使得低场强MR扫描仪在不提高梯度性能的情况下,便可实现快速成像,为提高我国在MR扫描仪上的研发水平奠定了基础。

To reduce the time of data scan and enhance the imaging speed in MRI,we make research on the compressed sensing MRI pulse sequence.Using variant density under -sampling acquisition,we designed a CS sequence based on the spin echo sequence. PPL language was used to program the sequence,which was realized on the permanent and super -conduct MR scanner.The under -sampling data from the CS sequence and the full sampling data from the spin -echo sequence were reconstructed and analyzed.The re-sult showed that the CS sequence met the speed requirement.The suitable acceleration factor was two and four for the data scanned on brain and knee respectively.The implementation of the CS pulse sequence makes it possible that rapid imaging can be realized on the low field MR scanner without improving the gradient performance.It has laid a foundation of improving the research and development level of the MR scanner in China.