Magnetic resonance diffusion imaging promises a long-sought noninvasive method for mapping neural connectivity in vivo. However, the connectivity estimates derived from diffusion imaging have not been experimentally validated in any systematic way, nor has the method been applied to test any novel anatomic hypotheses. In order for the connectivity maps obtained from diffusion imaging to be interpreted with any reasonable confidence, it will be necessary to validate the technique against """"""""gold-standard"""""""" tracer methods such as horse radish peroxidase histochemistry. In this project we propose to validate the connectivity maps obtained from diffusion imaging against the known cortical connectivity of the macaque monkey. The diffusion-based connectivity maps will exploit a novel diffusion imaging acquisition method called q-ball imaging, which is able to resolve complex intravoxel fiber crossings. The validation connectivity data set will be obtained from the CoCoMac neuroinformatics database that contains results from thousands of invasive tracer experiments in the macaque. This comparison will allow us to systematically evaluate the strengths and weaknesses of the diffusion method against a battery of classical histological techniques. We will then apply the optimized diffusion imaging method to test a series of hypotheses on the cortical connectivity of macaque visual system.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Mentored Quantitative Research Career Development Award (K25)
Project #
5K25NS046532-02
Application #
6799966
Study Section
NST-2 Subcommittee (NST)
Program Officer
Chen, Daofen
Project Start
2003-09-15
Project End
2008-08-31
Budget Start
2004-09-01
Budget End
2005-08-31
Support Year
2
Fiscal Year
2004
Total Cost
$146,151
Indirect Cost
Name
Massachusetts General Hospital
Department
Type
DUNS #
073130411
City
Boston
State
MA
Country
United States
Zip Code
02199
Khachaturian, Mark H; Arsenault, John; Ekstrom, Leeland B et al. (2008) Focal reversible deactivation of cerebral metabolism affects water diffusion. Magn Reson Med 60:1178-89
Whitcher, Brandon; Tuch, David S; Wisco, Jonathan J et al. (2008) Using the wild bootstrap to quantify uncertainty in diffusion tensor imaging. Hum Brain Mapp 29:346-62
Khachaturian, Mark H; Wisco, Jonathan J; Tuch, David S (2007) Boosting the sampling efficiency of q-Ball imaging using multiple wavevector fusion. Magn Reson Med 57:289-96
Ziyan, Ulas; Tuch, David; Westin, Carl-Fredrik (2006) Segmentation of thalamic nuclei from DTI using spectral clustering. Med Image Comput Comput Assist Interv 9:807-14
Rosas, H Diana; Tuch, David S; Hevelone, Nathanael D et al. (2006) Diffusion tensor imaging in presymptomatic and early Huntington's disease: Selective white matter pathology and its relationship to clinical measures. Mov Disord 21:1317-25
Tuch, David S; Salat, David H; Wisco, Jonathan J et al. (2005) Choice reaction time performance correlates with diffusion anisotropy in white matter pathways supporting visuospatial attention. Proc Natl Acad Sci U S A 102:12212-7
Tuch, David S; Wisco, Jonathan J; Khachaturian, Mark H et al. (2005) Q-ball imaging of macaque white matter architecture. Philos Trans R Soc Lond B Biol Sci 360:869-79
Tuch, David S (2004) Q-ball imaging. Magn Reson Med 52:1358-72
Tuch, David S; Reese, Timothy G; Wiegell, Mette R et al. (2003) Diffusion MRI of complex neural architecture. Neuron 40:885-95