title: Reduced Field-of-View Diffusion-Weighted Imaging of the Lumbosacral Enlargement: A Pilot In Vivo Study of the Healthy Spinal Cord at 3T.
abstract: Diffusion tensor imaging (DTI) has recently started to be adopted into clinical investigations of spinal cord (SC) diseases. However, DTI applications to the lower SC are limited due to a number of technical challenges, related mainly to the even smaller size of the SC structure at this level, its position relative to the receiver coil elements and the effects of motion during data acquisition. Developing methods to overcome these problems would offer new means to gain further insights into microstructural changes of neurological conditions involving the lower SC, and in turn could help explain symptoms such as bladder and sexual dysfunction. In this work, the feasibility of obtaining grey and white matter (GM/WM) DTI indices such as axial/radial/mean diffusivity (AD/RD/MD) and fractional anisotropy (FA) within the lumbosacral enlargement (LSE) was investigated using a reduced field-of-view (rFOV) single-shot echo-planar imaging (ss-EPI) acquisition in 14 healthy participants using a clinical 3T MR system. The scan-rescan reproducibility of the measurements was assessed by calculating the percentage coefficient of variation (%COV). Mean FA was higher in WM compared to GM (0.58 and 0.4 in WM and GM respectively), AD and MD were higher in WM compared to GM (1.66 μm2ms-1 and 0.94 μm2ms-1 in WM and 1.2 μm2ms-1 and 0.82 μm2ms-1 in GM for AD and MD respectively) and RD was lower in WM compared to GM (0.58 μm2ms-1 and 0.63 μm2ms-1 respectively). The scan-rescan %COV was lower than 10% in all cases with the highest values observed for FA and the lowest for MD. This pilot study demonstrates that it is possible to obtain reliable tissue-specific estimation of DTI indices within the LSE using a rFOV ss-EPI acquisition. The DTI acquisition and analysis protocol presented here is clinically feasible and may be used in future investigations of neurological conditions implicating the lower SC.
authors.affiliation: NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, University College London, London, United Kingdom.
authors.forename: Marios C
authors.identifier: http://orcid.org/0000-0003-4986-446X
authors.initials: MC
authors.lastname: Yiannakas
authors.affiliation: NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, University College London, London, United Kingdom.
authors.forename: Francesco
authors.initials: F
authors.lastname: Grussu
authors.affiliation: NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, University College London, London, United Kingdom.
authors.forename: Polymnia
authors.initials: P
authors.lastname: Louka
authors.affiliation: NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, University College London, London, United Kingdom.|Translational Imaging Group, Centre for Medical Image Computing, Medical Physics and Biomedical Engineering, University College London, London, United Kingdom.|University College London / University College London Hospitals National Institute for Health Research (NIHR) Biomedical Research Centre, London, United Kingdom.
authors.forename: Ferran
authors.initials: F
authors.lastname: Prados
authors.affiliation: NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, University College London, London, United Kingdom.
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Samson
authors.affiliation: NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, University College London, London, United Kingdom.
authors.forename: Marco
authors.initials: M
authors.lastname: Battiston
authors.affiliation: NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, University College London, London, United Kingdom.|Department of Medical Statistics, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Altmann
authors.affiliation: Translational Imaging Group, Centre for Medical Image Computing, Medical Physics and Biomedical Engineering, University College London, London, United Kingdom.|University College London / University College London Hospitals National Institute for Health Research (NIHR) Biomedical Research Centre, London, United Kingdom.
authors.forename: Sebastien
authors.initials: S
authors.lastname: Ourselin
authors.affiliation: NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, University College London, London, United Kingdom.|University College London / University College London Hospitals National Institute for Health Research (NIHR) Biomedical Research Centre, London, United Kingdom.
authors.forename: David H
authors.initials: DH
authors.lastname: Miller
authors.affiliation: NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, University College London, London, United Kingdom.|Brain MRI 3T Mondino Research Center, C. Mondino National Neurological Institute, Pavia, Italy.|Department of Brain and Behavioral Sciences, University of Pavia, Pavia, PV, Italy.
authors.forename: Claudia A M
authors.initials: CA
authors.lastname: Gandini Wheeler-Kingshott
mesh_terms: D000328:Adult; D005260:Female; D066128:Gray Matter / Q000000981:diagnostic imaging; D064368:Healthy Volunteers; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio; D013116:Spinal Cord / Q000000981:diagnostic imaging*; D066127:White Matter / Q000000981:diagnostic imaging; D055815:Young Adult