Abstract #3335

Quantitative Phenotype Characterization of Developing Mouse Brains by Diffusion Tensor Imaging: Application for the Frizzled-4-/- Mutant Mice

Manisha Aggarwal¹, Xin Ye², Jeremy Nathans^2,3, Michael I. Miller^1,4, Susumu Mori⁵, Jiangyang Zhang⁵

¹Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA; ²Department of Molecular Biology & Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA; ³Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA; ⁴Center of Imaging Science, Johns Hopkins University, Baltimore, MD, USA; ⁵Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA

Population-based quantitative analyses of DTI data was used to characterize phenotypic changes during development in the Frizzled-4 knockout (Fz4-/-) mutant mouse brain. Population-averaged anisotropy indices computed from normalized diffusion tensor fields for wild type and Fz4-/- mouse brains at postnatal day 7 (P7), P14, P21 and P30 were used to investigate the developmental abnormalities at each stage. DTI results indicated progressive disorganization of the cerebellar cellular architecture, consistent with previous histological findings, and revealed developmental anomalies characterized by differences in diffusion anisotropy in the dentate gyrus, olfactory bulb and several axonal tracts.