A modified damped Richardson–Lucy algorithm to reduce isotropic background effects in spherical deconvolution

Dell’Acqua, Flavio; Scifo, Paola; Rizzo, Giovanna; Catani, Marco; Simmons, Andrew; Scotti, Giuseppe; Fazio, Ferruccio

doi:10.1016/j.neuroimage.2009.09.033

Cited by 298 publications

(344 citation statements)

References 48 publications

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“…SD (Tournier et al, 2004, Kaden et al, 2007, Tournier et al, 2007, Descoteaux et al, 2009, Dell'Acqua et al, 2010 translates, for each voxel, the direction dependent signal attenuation into an fODF. The idea behind SD is that the measured signal profile can be expressed as convolution of a kernel K and the fODF Ψ.…”

Section: Theory Spherical Deconvolution (Sd)mentioning

confidence: 99%

Beyond fractional anisotropy: Extraction of bundle-specific structural metrics from crossing fiber models

et al. 2014

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Diffusion MRI (dMRI) measurements are used for inferring the microstructural properties of white matter and to reconstruct fiber pathways. Very often voxels contain complex fiber configurations comprising multiple bundles, rendering the simple diffusion tensor model unsuitable. Multi-compartment models deliver a convenient parameterization of the underlying complex fiber architecture, but pose challenges for fitting and model selection. Spherical deconvolution, in contrast, very economically produces a fiber orientation density function (fODF) without any explicit model assumptions. Since, however, the fODF is represented by spherical harmonics, a direct interpretation of the model parameters is impossible. Based on the fact that the fODF can often be interpreted as superposition of multiple peaks, each associated to one relatively coherent fiber population (bundle), we offer a solution that seeks to combine the advantages of both approaches: first the fiber configuration is modeled as fODF represented by spherical harmonics and then each of the peaks is parameterized separately in order to characterize the underlying bundle. In this work, the fODF peaks are approximated by Bingham distributions, capturing first and second order statistics of the fiber orientations, from which we derive metrics for the parametric quantification of fiber bundles. We propose meaningful relationships between these measures and the underlying microstructural properties. We focus on metrics derived directly from properties of the Bingham distribution, such as peak length, peak direction, peak spread, integral over the peak, as well as a metric derived from the comparison of the largest peaks, which probes the complexity of the underlying microstructure. We compare these metrics to the conventionally used fractional anisotropy (FA) and show how they may help to increase the specificity of the characterization of microstructural properties. While metric relying on the first moments of the Bingham distributions provide relatively robust results, second-order metrics representing the peak spread are only meaningful, if the SNR is very high and no fiber crossings are present in the voxel.

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Section: Theory Spherical Deconvolution (Sd)mentioning

confidence: 99%

Beyond fractional anisotropy: Extraction of bundle-specific structural metrics from crossing fiber models

et al. 2014

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“…Whole‐brain tractography was performed for each participant using the damped Richardson‐Lucy spherical deconvolution algorithm (Dell'acqua et al., 2010), which allows the recovery of multiple fiber orientations within each voxel, including those affected by partial volume. The tracking algorithm estimated peaks in the fiber orientation density function (fODF) at the center of each image voxel, and seed points were positioned at the vertices of a 2 × 2 × 2 mm grid superimposed over the image.…”

Section: Methodsmentioning

confidence: 99%

“…This study, therefore, employed the damped Richardson‐Lucy algorithm (Dell'acqua et al., 2010) for deterministic tractography on high angular resolution diffusion imaging data (HARDI) (Tuch et al., 2002) to visualize those axons linked, respectively, to the anterior hippocampus and to the posterior hippocampus. The extent of overlap between the reconstructions was then determined quantitatively.…”

Section: Introductionmentioning

confidence: 99%

Topographic separation of fornical fibers associated with the anterior and posterior hippocampus in the human brain: An MRI‐diffusion study

et al. 2016

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Background and ObjectiveEvidence from rat and nonhuman primate studies indicates that axons comprising the fornix have a characteristic topographical organization: projections from the temporal/anterior hippocampus mainly occupy the lateral fornix, whereas the more medial fornix contains fibers from the septal/posterior hippocampus. The aim of this study was to investigate whether the same topographical organization exists in the human brain.MethodsUsing high angular resolution diffusion MRI‐based tractography at 3T, subdivisions of the fornix were reconstructed in 40 healthy adults by selecting fiber pathways from either the anterior or the posterior hippocampus.ResultsThe tract reconstructions revealed that anterior hippocampal fibers predominantly comprise the lateral body of the fornix, whereas posterior fibers make up the medial body of the fornix. Quantitative analyses support this medial:lateral distinction in humans, which matches the topographical organization of the fornix in other primates.ConclusionThis novel tractography protocol enables the separation of fornix fibers from anterior and posterior hippocampal regions in the human brain and, hence, provides a means by which to compare functions associated with different sets of connections along the longitudinal axis of the hippocampus.

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“…Un faisceau longitudinal supé-rieur II plus gros dans l'hémisphère droit que dans l'hémisphère gauche est donc associé avec un traitement visuospatial plus rapide des évènements survenant à gauche comparé à ceux survenant à droite. En conclusion le degré de dominance de l'hémisphère droit pour le traitement visuospatial est associé à la taille du faisceau longitudinal supérieur II dans de 20 participants sains avec une nouvelle technologie d'imagerie par réso-nance magnétique qui permet d'explorer les connexions cérébrales chez l'être vivant : la tractographie des déconvolu-tions sphériques (SD) calculées à partir de l'imagerie par résonance magnétique (IRM) pondérée par la diffusion (DWI) [6,7] (voir Encadré). En parallèle, nous avons mesuré le degré de dominance de l'hémisphère cérébral droit avec des tests neuropsychologiques comme la bissection de ligne et une expérience simple de détection de cibles dans les champs visuels gauche et droit.…”

Section: Vers Des Applications Thérapeutiques ?unclassified

L’étude des connexions cérébrales révèle les bases anatomiques de la dominance de l’hémisphère droit pour l’attention spatiale

Schotten

2012

Med Sci (Paris)

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A modified damped Richardson–Lucy algorithm to reduce isotropic background effects in spherical deconvolution

Cited by 298 publications

References 48 publications

Beyond fractional anisotropy: Extraction of bundle-specific structural metrics from crossing fiber models

Beyond fractional anisotropy: Extraction of bundle-specific structural metrics from crossing fiber models

Topographic separation of fornical fibers associated with the anterior and posterior hippocampus in the human brain: An MRI‐diffusion study

L’étude des connexions cérébrales révèle les bases anatomiques de la dominance de l’hémisphère droit pour l’attention spatiale

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