In Vivo Imaging of Kurtosis Tensor Eigenvalues in the Brain at 3 T

Eric Edward Sigmund¹, Mariana Lazar¹, Jens H. Jensen¹, Joseph A. Helpern¹

Diffusion kurtosis imaging (DKI) quantifies the well-known non-gaussianity of apparent diffusion in biological tissue, and its directionally averaged mean kurtosis (MK) has potential clinical utility in the brain. However, the complete rank-4 kurtosis tensor contains more information that may be reduced, as in diffusion tensor diagonalization, to characteristic properties. The present study applies the recently described spectral decomposition to derive the eigenvalues/eigentensors of the kurtosis tensor, and resolve them spatially in a full brain 3 T DW-MRI scan. Maps of kurtosis eigenvalues and composite eigensurfaces derived from eigentensor projections present new contrast, potentially involving fiber crossing and barrier-density anisotropy.