Differential information content in staggered multiple shell hardi measured by the tensor distribution function

Diffusion tensor imaging has accelerated the study of brain connectivity, but single-tensor diffusion models are too simplistic to model fiber crossing and mixing. Hybrid diffusion imaging (HYDI) samples the radial and angular structure of local diffusion on multiple spherical shells in qspace, combining the high SNR and CNR achievable at low and high b-values, respectively. We acquired and analyzed human multi-shell HARDI at ultra-high field-strength (7 Tesla; b=1000, 2000, 3000 s/mm2 ). In experiments with the tensor distribution function (TDF), the b-value affected the intrinsic uncertainty for estimating component fiber orientations and their diffusion eigenvalues. We computed orientation density functions by least-squares fitting in multiple HARDI shells simultaneously. Within the range examined, higher b-values gave improved orientation estimates but poorer eigenvalue estimates; lower b-values showed opposite strengths and weaknesses. Combining these strengths, multiple-shell HA...

• Type: Journal
• Year: 2011
• Where: ISBI
• Authors: Liang Zhan, Alex D. Leow, Iman Aganj, Christophe Lenglet, Guillermo Sapiro, Essa Yacoub, Noam Harel, Arthur W. Toga, Paul M. Thompson
• Keywords: Diffusion Imaging, Diffusion Models, Diffusion Tensor Imaging, ISBI 2011, Medical Imaging