Validation of in vitro probabilistic tractography

Dyrby, Tim B.; Søgaard, Lise Vejby; Parker, Geoffrey; Alexander, Daniel C.; Lind, Nanna Marie; Baaré, William F.C.; Hay‐Schmidt, Anders; Eriksen, Nina; Pakkenberg, Bente; Paulson, Olaf B.; Jelsing, Jacob

doi:10.1016/j.neuroimage.2007.06.022

Cited by 206 publications

(198 citation statements)

References 40 publications

Supporting

Mentioning

191

Contrasting

Order By: Relevance

“…However, in these studies the validation was based primarily on qualitative observations. Studies that assessed the accuracy of DWI tractography by quantifying the overlap fraction between tracer-labeled regions and tractography (39,40) found that DWI tractography missed some of the tracer-labeled target regions (i.e., false negatives). However, these previous studies differ from the present study in three ways.…”

Section: Discussionmentioning

confidence: 99%

“…However, the gain in sensitivity comes at the cost of reduced specificity. Second, in the previous studies, the tractography results were constrained either by waypoints (34,39) or orientation-specific ROIs (38). Using a priori anatomical knowledge to constrain tractography is likely to reduce the occurrence of false-positive trajectories but precludes an objective assessment of the ability of the technique to reveal the trajectory of fiber pathways that are currently unknown.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Anatomical accuracy of brain connections derived from diffusion MRI tractography is inherently limited

Thomas

İrfanoğlu

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

708

633

View full text Add to dashboard Cite

Tractography based on diffusion-weighted MRI (DWI) is widely used for mapping the structural connections of the human brain. Its accuracy is known to be limited by technical factors affecting in vivo data acquisition, such as noise, artifacts, and data undersampling resulting from scan time constraints. It generally is assumed that improvements in data quality and implementation of sophisticated tractography methods will lead to increasingly accurate maps of human anatomical connections. However, assessing the anatomical accuracy of DWI tractography is difficult because of the lack of independent knowledge of the true anatomical connections in humans. Here we investigate the future prospects of DWI-based connectional imaging by applying advanced tractography methods to an ex vivo DWI dataset of the macaque brain. The results of different tractography methods were compared with maps of known axonal projections from previous tracer studies in the macaque. Despite the exceptional quality of the DWI data, none of the methods demonstrated high anatomical accuracy. The methods that showed the highest sensitivity showed the lowest specificity, and vice versa. Additionally, anatomical accuracy was highly dependent upon parameters of the tractography algorithm, with different optimal values for mapping different pathways. These results suggest that there is an inherent limitation in determining long-range anatomical projections based on voxelaveraged estimates of local fiber orientation obtained from DWI data that is unlikely to be overcome by improvements in data acquisition and analysis alone.T he creation of a comprehensive map of the connectional neuroanatomy of the human brain would be a fundamental achievement in neuroscience. However, despite the numerous efforts to date (for a historical review, see ref. 1), creating this map remains a challenge. A major limitation is that the current goldstandard technique for mapping structural connections, which requires the injection of axonal tracers, cannot be used in humans. The introduction of diffusion-weighted MRI (DWI) (2-4) and the subsequent advent of diffusion tensor MRI (DTI) (5) opened the possibility of exploring the structural properties of white matter in the living human brain (6). Local DWI measures are used clinically for the early detection of stroke and for the characterization of neurological disorders such as multiple sclerosis, epilepsy, and brain gliomas, among others (7). In addition, tractography approaches (8-12) that can infer structural brain connectivity based on brain-wide local DWI measurement have been developed (for reviews, see refs. 13 and 14). The success of DWI tractography as a method for studying fiber trajectories has led to a systematic characterization of large white-matter pathways of the living human brain (e.g., ref. 15), and now it is used routinely to provide a structural explanation for aspects of human brain function (16).A major limitation of DWI tractography is that its characterization of axonal pathways is based on indirec...

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Anatomical accuracy of brain connections derived from diffusion MRI tractography is inherently limited

Thomas

İrfanoğlu

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

708

633

View full text Add to dashboard Cite

show abstract

“…that the anisotropic diffusion signal formed by the small fraction of axonal collaterals in the dense white matter could be detected with simple DT (Lundell et al 2011). Finally, although the fact that tractography produces robust results across subjects do not guarantee the validity of the findings (Dyrby et al 2007), the consistency of results obtained with tracing and DT encouraged extending the study to the in vivo human brain.…”

Section: Dt Topographymentioning

confidence: 98%

The Crossed Projection to the Striatum in Two Species of Monkey and in Humans: Behavioral and Evolutionary Significance

et al. 2016

Self Cite

View full text Add to dashboard Cite

The corpus callosum establishes the anatomical continuity between the 2 hemispheres and coordinates their activity. Using histological tracing, single axon reconstructions, and diffusion tractography, we describe a callosal projection to n caudatus and putamen in monkeys and humans. In both species, the origin of this projection is more restricted than that of the ipsilateral projection. In monkeys, it consists of thin axons (0.4-0.6 μm), appropriate for spatial and temporal dispersion of subliminal inputs. For prefrontal cortex, contralateral minus ipsilateral delays to striatum calculated from axon diameters and conduction distance are <2 ms in the monkey and, by extrapolation, <4 ms in humans. This delay corresponds to the performance in Poffenberger's paradigm, a classical attempt to estimate central conduction delays, with a neuropsychological task. In both species, callosal cortico-striatal projections originate from prefrontal, premotor, and motor areas. In humans, we discovered a new projection originating from superior parietal lobule, supramarginal, and superior temporal gyrus, regions engaged in language processing. This projection crosses in the isthmus the lesion of which was reported to dissociate syntax and prosody. The projection might originate from an overproduction of callosal projections in development, differentially pruned depending on species.

show abstract

“…Using the porcine brain Dyrby et al (2007) quantitatively and qualitatively assessed the anatomical validity and reproducibility of in vitro multi-fiber probabilistic tractography against two invasive tracers. They demonstrated that probabilistic tractography reliably detected specific pathways and concluded that tractography can be a precise tool in studying anatomical brain connectivity.…”

Section: Validation Of Mr Tractography and Connectivity Mapsmentioning

confidence: 99%

MR connectomics: Principles and challenges

Hagmann

Cammoun

Gigandet

et al. 2010

Journal of Neuroscience Methods

257

207

View full text Add to dashboard Cite

a b s t r a c t MR connectomics is an emerging framework in neuro-science that combines diffusion MRI and whole brain tractography methodologies with the analytical tools of network science. In the present work we review the current methods enabling structural connectivity mapping with MRI and show how such data can be used to infer new information of both brain structure and function. We also list the technical challenges that should be addressed in the future to achieve high-resolution maps of structural connectivity. From the resulting tremendous amount of data that is going to be accumulated soon, we discuss what new challenges must be tackled in terms of methods for advanced network analysis and visualization, as well data organization and distribution. This new framework is well suited to investigate key questions on brain complexity and we try to foresee what fields will most benefit from these approaches.

show abstract

Validation of in vitro probabilistic tractography

Cited by 206 publications

References 40 publications

Anatomical accuracy of brain connections derived from diffusion MRI tractography is inherently limited

Anatomical accuracy of brain connections derived from diffusion MRI tractography is inherently limited

The Crossed Projection to the Striatum in Two Species of Monkey and in Humans: Behavioral and Evolutionary Significance

MR connectomics: Principles and challenges

Contact Info

Product

Resources

About