title: Referenceless one-dimensional Nyquist ghost correction in multicoil single-shot spatiotemporally encoded MRI.
abstract: Single-shot spatiotemporally encoded (SPEN) MRI is a novel fast imaging method capable of retaining the time efficiency of single-shot echo planar imaging (EPI) but with distortion artifacts significantly reduced. Akin to EPI, the phase inconsistencies between mismatched even and odd echoes also result in the so-called Nyquist ghosts. However, the characteristic of the SPEN signals provides the possibility of obtaining ghost-free images directly from even and odd echoes respectively, without acquiring additional reference scans. In this paper, a theoretical analysis of the Nyquist ghosts manifested in single-shot SPEN MRI is presented, a one-dimensional correction scheme is put forward capable of maintaining definition of image features without blurring when the phase inconsistency along SPEN encoding direction is negligible, and a technique is introduced for convenient and robust correction of data from multi-channel receiver coils. The effectiveness of the proposed processing pipeline is validated by a series of experiments conducted on simulation data, in vivo rats and healthy human brains. The robustness of the method is further verified by implementing distortion correction on ghost corrected data.
authors.affiliation: Center for Brain Imaging Science and Technology, Zhejiang University, Hangzhou, China. Electronic address: panschen@zju.edu.cn.
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Institute of Neuroscience and Medicine-4, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany. Electronic address: y.liao@fz-juelich.de.
authors.forename: Yupeng
authors.initials: Y
authors.lastname: Liao
authors.affiliation: Center for Brain Imaging Science and Technology, Zhejiang University, Hangzhou, China. Electronic address: lishayuan@zju.edu.cn.
authors.forename: Lisha
authors.initials: L
authors.lastname: Yuan
authors.affiliation: MR Collaboration Northeast Asia, Siemens Healthcare, Shanghai, China. Electronic address: lh.liu@siemens.com.
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.affiliation: Institute of Neuroscience and Medicine-4, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany. Electronic address: s.yun@fz-juelich.de.
authors.forename: Seong Dae
authors.initials: SD
authors.lastname: Yun
authors.affiliation: Institute of Neuroscience and Medicine-4, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany. Electronic address: n.j.shah@fz-juelich.de.
authors.forename: Nadim Joni
authors.initials: NJ
authors.lastname: Shah
authors.affiliation: Department of Electronic Science, Xiamen University, Xiamen, China. Electronic address: chenz@xmu.edu.cn.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Center for Brain Imaging Science and Technology, Zhejiang University, Hangzhou, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, China; Department of Imaging Sciences, University of Rochester, Rochester, USA. Electronic address: jzhong3@zju.edu.cn.
authors.forename: Jianhui
authors.initials: J
authors.lastname: Zhong
mesh_terms: D000818:Animals; D016477:Artifacts; D001921:Brain / Q000000981:diagnostic imaging*; D017352:Echo-Planar Imaging / Q000379:methods; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods*; D023421:Models, Animal; D019047:Phantoms, Imaging; D051381:Rats
keywords: Distortion correction; Multichannel MRI; Nyquist ghost correction; Reference free correction; Spatiotemporal encoding