title: Comparison of Diffusion MRI Acquisition Protocols for the In Vivo Characterization of the Mouse Spinal Cord: Variability Analysis and Application to an Amyotrophic Lateral Sclerosis Model.
abstract: Diffusion-weighted Magnetic Resonance Imaging (dMRI) has relevant applications in the microstructural characterization of the spinal cord, especially in neurodegenerative diseases. Animal models have a pivotal role in the study of such diseases; however, in vivo spinal dMRI of small animals entails additional challenges that require a systematical investigation of acquisition parameters. The purpose of this study is to compare three acquisition protocols and identify the scanning parameters allowing a robust estimation of the main diffusion quantities and a good sensitivity to neurodegeneration in the mouse spinal cord. For all the protocols, the signal-to-noise and contrast-to noise ratios and the mean value and variability of Diffusion Tensor metrics were evaluated in healthy controls. For the estimation of fractional anisotropy less variability was provided by protocols with more diffusion directions, for the estimation of mean, axial and radial diffusivity by protocols with fewer diffusion directions and higher diffusion weighting. Intermediate features (12 directions, b = 1200 s/mm2) provided the overall minimum inter- and intra-subject variability in most cases. In order to test the diagnostic sensitivity of the protocols, 7 G93A-SOD1 mice (model of amyotrophic lateral sclerosis) at 10 and 17 weeks of age were scanned and the derived diffusion parameters compared with those estimated in age-matched healthy animals. The protocols with an intermediate or high number of diffusion directions provided the best differentiation between the two groups at week 17, whereas only few local significant differences were highlighted at week 10. According to our results, a dMRI protocol with an intermediate number of diffusion gradient directions and a relatively high diffusion weighting is optimal for spinal cord imaging. Further work is needed to confirm these results and for a finer tuning of acquisition parameters. Nevertheless, our findings could be important for the optimization of acquisition protocols for preclinical and clinical dMRI studies on the spinal cord.
authors: Scientific Direction, Fondazione IRCCS Istituto Neurologico "Carlo Besta" Milan, Italy.
authors: Matteo
authors: M
authors: Figini
authors: Scientific Direction, Fondazione IRCCS Istituto Neurologico "Carlo Besta" Milan, Italy.
authors: Alessandro
authors: A
authors: Scotti
authors: Neurology IV-Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy.
authors: Stefania
authors: S
authors: Marcuzzo
authors: Neurology IV-Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy.
authors: Silvia
authors: S
authors: Bonanno
authors: Scientific Direction, Fondazione IRCCS Istituto Neurologico "Carlo Besta" Milan, Italy.
authors: Francesco
authors: F
authors: Padelli
authors: Neuronal and Tissue Regeneration Laboratory, Centro de Investigación Príncipe Felipe, Valencia, Spain.
authors: Victoria
authors: V
authors: Moreno-Manzano
authors: Unidad de Neurobiología comparada, Universidad de Valencia, Valencia, Spain.
authors: José Manuel
authors: JM
authors: García-Verdugo
authors: Neurology IV-Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy.
authors: Pia
authors: P
authors: Bernasconi
authors: Neurology IV-Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy.
authors: Renato
authors: R
authors: Mantegazza
authors: Neuroradiology, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy.
authors: Maria Grazia
authors: MG
authors: Bruzzone
authors: Scientific Direction, Fondazione IRCCS Istituto Neurologico "Carlo Besta" Milan, Italy.
authors: Ileana
authors: I
authors: Zucca
mesh_terms: D000483:Alleles; D000690:Amyotrophic Lateral Sclerosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D000818:Animals; D016880:Anisotropy; D004058:Diffusion; D038524:Diffusion Magnetic Resonance Imaging; D004195:Disease Models, Animal; D007091:Image Processing, Computer-Assisted; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009154:Mutation; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio; D013116:Spinal Cord / Q000000981:diagnostic imaging* / Q000503:physiopathology; D000072105:Superoxide Dismutase-1 / Q000235:genetics
chemical_list: C000606290:SOD1 protein, human; D000072105:Superoxide Dismutase-1