Referenceless interleaved echo-planar imaging.
TL;DR: It is shown mathematically and experimentally that system time delays are orientation dependent, resulting from anisotropic physical gradient delays, and “Compensation blips” are proposed for time delay correction.
read more
Abstract: Interleaved echo-planar imaging (EPI) is an ultrafast imaging technique important for applications that require high time resolution or short total acquisition times. Unfortunately, EPI is prone to significant ghosting artifacts, resulting primarily from system time delays that cause data matrix misregistration. In this work, it is shown mathematically and experimentally that system time delays are orientation dependent, resulting from anisotropic physical gradient delays. This analysis characterizes the behavior of time delays in oblique coordinates, and a new ghosting artifact caused by anisotropic delays is described. ‘‘Compensation blips’’ are proposed for time delay correction. These blips are shown to remove the effects of anisotropic gradient delays, eliminating the need for repeated reference scans and postprocessing corrections. Examples of phantom and in vivo images are shown. Magn Reson Med 41:87‐94, 1999. r 1999 Wiley-Liss, Inc.
read more
Chat with Paper
AI Agents for this Paper
Find similar papers on Google Scholar, PubMed and Arxiv
Write a critical review of this paper
Analyze citations of this paper to find unaddressed research gaps
Citations
Centering the projection reconstruction trajectory: reducing gradient delay errors.
TL;DR: The projection reconstruction (PR) trajectory was investigated for the effect of gradient timing delays between the actual and requested start time of each physical gradient, and artifacts were reduced in phantom images and in volunteer studies.
188
Foundations of MRI phase imaging and processing for Quantitative Susceptibility Mapping (QSM)
TL;DR: Starting with the fundamental relation between MRI signal and tissue magnetic susceptibility this review covers the reconstruction of magnetic field maps from multi-channel phase images, background field correction, and provides an overview of state of the art QSM solution strategies.
133
Robust EPI Nyquist ghost elimination via spatial and temporal encoding.
TL;DR: This work proposes integrating PLACE into a PAGE‐based reconstruction process to yield significantly better Nyquist ghost correction that is more robust than PLACE or PAGE alone.
55
Free-breathing liver fat quantification using a multiecho 3D stack-of-radial technique.
Tess Armstrong,Isabel Dregely,Isabel Dregely,Alto Stemmer,Fei Han,Yutaka Natsuaki,Kyunghyun Sung,Holden H. Wu +7 more
TL;DR: A novel free‐breathing 3D stack‐of‐radial (FB radial) liver fat quantification technique is developed and evaluated in a preliminary study.
50
Automatic correction of echo‐planar imaging (EPI) ghosting artifacts in real‐time interactive cardiac MRI using sensitivity encoding
TL;DR: To develop a method that automatically corrects ghosting artifacts due to echo‐misalignment in interleaved gradient‐echo echo‐planar imaging (EPI) in arbitrary oblique or double‐oblique scan planes.
46
References
•Book
Discrete-Time Signal Processing
Alan V. Oppenheim,Ronald W. Schafer +1 more
- 01 Jan 1989
TL;DR: In this paper, the authors provide a thorough treatment of the fundamental theorems and properties of discrete-time linear systems, filtering, sampling, and discrete time Fourier analysis.
11.8K
Multi-planar image formation using nmr spin echoes.
TL;DR: In this paper, a two-dimensional spin density imaging by nuclear magnetic resonance (NMR) is proposed, which exploits the properties of spin echoes in time-dependent magnetic field gradients.
Echo-planar imaging: magnetic resonance imaging in a fraction of a second
TL;DR: Through shortened patient examination times, higher patient throughput, and lower cost per MRI examination, EPI may become a powerful tool for early diagnosis of some common and potentially treatable diseases such as ischemic heart disease, stroke, and cancer.
672
GRASE (Gradient-and Spin-Echo) imaging: A novel fast MRI technique
Koichi Oshio,David A. Feinberg +1 more
TL;DR: A fast multi‐section MR imaging technique that utilizes the speed advantages of gradient refocusing while overcoming the image artifacts arising from static field inhomogeneity and chemical shift is described.
393
Functional magnetic resonance imaging with echo planar imaging.
Kenneth K. Kwong
- 01 Jan 1996
TL;DR: In this report, a review is made of the mechanism behind the functional MRI (fMRI) signals and the advances made in many different areas of fMRI.
202