title: Assessing the performance of different DTI motion correction strategies in the presence of EPI distortion correction.
abstract: Diffusion tensor imaging (DTI) is susceptible to several artifacts due to eddy currents, echo planar imaging (EPI) distortion and subject motion. While several techniques correct for individual distortion effects, no optimal combination of DTI acquisition and processing has been determined. Here, the effects of several motion correction techniques are investigated while also correcting for EPI distortion: prospective correction, using navigation; retrospective correction, using two different popular packages (FSL and TORTOISE); and the combination of both methods. Data from a pediatric group that exhibited incidental motion in varying degrees are analyzed. Comparisons are carried while implementing eddy current and EPI distortion correction. DTI parameter distributions, white matter (WM) maps and probabilistic tractography are examined. The importance of prospective correction during data acquisition is demonstrated. In contrast to some previous studies, results also show that the inclusion of retrospective processing also improved ellipsoid fits and both the sensitivity and specificity of group tractographic results, even for navigated data. Matches with anatomical WM maps are highest throughout the brain for data that have been both navigated and processed using TORTOISE. The inclusion of both prospective and retrospective motion correction with EPI distortion correction is important for DTI analysis, particularly when studying subject populations that are prone to motion. Hum Brain Mapp 37:4405-4424, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Human Biology, Faculty of Health Sciences, MRC/UCT Medical Imaging Research Unit, University of Cape Town, South Africa.|African Institute for Mathematical Sciences, Muizenberg, Western Cape, South Africa.|Scientific and Statistical Computing Core, National Institutes of Health, Bethesda, Maryland.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Taylor
authors.affiliation: Department of Human Biology, Faculty of Health Sciences, MRC/UCT Medical Imaging Research Unit, University of Cape Town, South Africa.
authors.forename: A
authors.initials: A
authors.lastname: Alhamud
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Andre
authors.initials: A
authors.lastname: van der Kouwe
authors.affiliation: Department of Human Biology, Faculty of Health Sciences, MRC/UCT Medical Imaging Research Unit, University of Cape Town, South Africa.
authors.forename: Muhammad G
authors.initials: MG
authors.lastname: Saleh
authors.affiliation: Department of Paediatrics and Child Health, Stellenbosch University, Children's Infection Diseases Clinical Research Unit, South Africa.
authors.forename: Barbara
authors.initials: B
authors.lastname: Laughton
authors.affiliation: Department of Human Biology, Faculty of Health Sciences, MRC/UCT Medical Imaging Research Unit, University of Cape Town, South Africa.
authors.forename: Ernesta
authors.initials: E
authors.lastname: Meintjes
mesh_terms: D016477:Artifacts; D001921:Brain / Q000000981:diagnostic imaging; D002648:Child; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009038:Motion; D066127:White Matter / Q000000981:diagnostic imaging
keywords: diffusion tensor imaging; echo planar imaging volumetric navigator; fractional anisotropy; motion correction; tractography