Meeting Banner
Abstract #1104

Validation of Tractography Against in vivo Tracing in the Macaque Visual System Effect of Distance Correction

Hojjatollah Azadbakht1, 2, Laura M. Parkes1, 2, Hamied A. Haroon1, 2, Mark Augarth3, Nikos K. Logothetis3, Alex de Crespigny4, Helen E. DArceuil4, Geoffrey J M Parker1, 2

1Imaging Science and Biomedical Engineering, School of Cancer and Imaging Sciences, University of Manchester, Manchester, United Kingdom; 2The Biomedical Imaging Institute, University of Manchester, Manchester, United Kingdom; 3Max Planck Institute for Biological Cybernetics, Tubingen, Germany; 4Athinoula A. Martinos Center, MGH, Charlestown, MA, United States

Validation of diffusion imaging has proved difficult due to the lack of an adequate gold-standard. In this work, the macaque visual system is used as a model, in which due to an extensive literature of in-vivo and post-mortem tracer studies, true connections are well-established. We performed probabilistic tractography on diffusion imaging data from two in-vitro macaque brains, and comparisons were made between identified connections at different thresholds of connection strength, and connections identified in the visual system wiring map of Felleman & van Essen. The effects of streamline-length based correction of the distance bias of probabilistic tractography were also explored.

Keywords

absent acceptance accuracy acquisition affected agreement assumed atlas available berg beyond bins biological biomedical bore boundary brain brains caret certain chance collinear connect connection connections connectivity correction corrections correctly cortical cybernetics dataset datasets declines deconvolution density derived described despite detailed determined developed difficult diffusion distance emerging examination explore explored extend fact false formalin function gold good greatly hemisphere hours identification identified implemented important improvements in vivo influence institute interconnection interpretation interrogate invasive isotropic kingdom known lack length lesions linear long macaque made many markedly matrices matrix measure measuring model multiplied needed negatives notes optimum overall parker part partitioning passed paths percentage performance positive post previous previously probabilistic probability protocols proved reflect reported residual resolution respectively role scaled scanner school science seed series shots software spatially spherical spin square straightest streamline streamlines strength strengths studies subjected success system though threshold thresholded thresholds tool tracer tracing trans transformation true uncorrected understanding validation vertical visible visual