title: Correction for Eddy Current-Induced Echo-Shifting Effect in Partial-Fourier Diffusion Tensor Imaging.
abstract: In most diffusion tensor imaging (DTI) studies, images are acquired with either a partial-Fourier or a parallel partial-Fourier echo-planar imaging (EPI) sequence, in order to shorten the echo time and increase the signal-to-noise ratio (SNR). However, eddy currents induced by the diffusion-sensitizing gradients can often lead to a shift of the echo in k-space, resulting in three distinct types of artifacts in partial-Fourier DTI. Here, we present an improved DTI acquisition and reconstruction scheme, capable of generating high-quality and high-SNR DTI data without eddy current-induced artifacts. This new scheme consists of three components, respectively, addressing the three distinct types of artifacts. First, a k-space energy-anchored DTI sequence is designed to recover eddy current-induced signal loss (i.e., Type 1 artifact). Second, a multischeme partial-Fourier reconstruction is used to eliminate artificial signal elevation (i.e., Type 2 artifact) associated with the conventional partial-Fourier reconstruction. Third, a signal intensity correction is applied to remove artificial signal modulations due to eddy current-induced erroneous T2(∗) -weighting (i.e., Type 3 artifact). These systematic improvements will greatly increase the consistency and accuracy of DTI measurements, expanding the utility of DTI in translational applications where quantitative robustness is much needed.
authors.affiliation: Brain Imaging and Analysis Center, Duke University Medical Center, 2424 Erwin Road No. 501, Durham, NC 27705, USA.
authors.forename: Trong-Kha
authors.initials: TK
authors.lastname: Truong
authors.affiliation: Brain Imaging and Analysis Center, Duke University Medical Center, 2424 Erwin Road No. 501, Durham, NC 27705, USA.
authors.forename: Allen W
authors.initials: AW
authors.lastname: Song
authors.affiliation: Brain Imaging and Analysis Center, Duke University Medical Center, 2424 Erwin Road No. 501, Durham, NC 27705, USA.
authors.forename: Nan-Kuei
authors.initials: NK
authors.lastname: Chen
mesh_terms: D016477:Artifacts; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005583:Fourier Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*