Vishal Patel1, Mariko Fitzgibbons1, Paul M Thompson2, Arthur W Toga2, and Noriko Salamon1
1University of California, Los Angeles, Los Angeles, CA, United States, 2University of Southern California, Los Angeles, CA, United States
To avoid the assumptions inherent in diffusion modeling and tractography, we develop a new approach for studying global white matter development that operates on diffusion-weighted MR images directly. We apply a sparse coding method, K-SVD, to decompose a diffusion-weighted series. We quantify the efficiency of the resulting encoding by computing the Gini coefficient. We then show that this measure increases in a predictable manner throughout normal pediatric development. Our results support the hypotheses that more organized white matter can be more sparsely encoded and that the sparsity of the encoding may thus be used to infer the state of development.