title: Variable density sampling and non-Cartesian super-resolved reconstruction for spatiotemporally encoded single-shot MRI.
abstract: Spatiotemporally encoded (SPEN) single-shot MRI is an emerging ultrafast technique, which is capable of spatially selective acquisition and reduced field-of-view imaging. Compared to uniform sampling, variable density sampling has great potential in reducing aliasing artifacts and improving sampling efficiency. In this study, variable density spiral trajectory and non-Cartesian super-resolved (SR) reconstruction method are developed for SPEN MRI. The gradient waveforms design of spiral trajectory is mathematically described as an optimization problem subjected to the limitations of hardware. Non-Cartesian SR reconstruction with specific gridding method is developed to retrieve a resolution enhanced image from raw SPEN data. The robustness and efficiency of the proposed methods are demonstrated by numerical simulation and various experiments. The results indicate that variable density SPEN MRI can provide better spatial resolution and fewer aliasing artifacts compared to Cartesian counterpart. The proposed methods will facilitate the development of variable density SPEN MRI.
authors: Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Electronic Science, Xiamen University, Xiamen 361005, China; Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States. Electronic address: chenlin@stu.xmu.edu.cn.
authors: Lin
authors: L
authors: Chen
authors: Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Electronic Science, Xiamen University, Xiamen 361005, China. Electronic address: jphuang@stu.xmu.edu.cn.
authors: Jianpan
authors: J
authors: Huang
authors: Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Electronic Science, Xiamen University, Xiamen 361005, China. Electronic address: zt_nmr@stu.xmu.edu.cn.
authors: Ting
authors: T
authors: Zhang
authors: Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Electronic Science, Xiamen University, Xiamen 361005, China. Electronic address: lij416@163.com.
authors: Jing
authors: J
authors: Li
authors: Department of Communication Engineering, Xiamen University, Xiamen 361005, China. Electronic address: cbcai@xmu.edu.cn.
authors: Congbo
authors: C
authors: Cai
authors: Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Electronic Science, Xiamen University, Xiamen 361005, China. Electronic address: shcai@xmu.edu.cn.
authors: Shuhui
authors: S
authors: Cai
keywords: Gradient waveforms design; Spatiotemporal encoding; Super-resolved reconstruction; Ultrafast MRI; Variable density sampling