Abstract #1647

CSF Contamination Correction in DTI Tractography of the Fornix in Elderly Subjects

Sinchai Tsao¹, Darryl H. Hwang¹, Manbir Singh,¹²

¹Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States; ²Department of Radiology, University of Southern California, Los Angeles, CA, United States

The microstructural integrity of the limbic regions is frequently compromised in neurodegenerative diseases such as Alzheimer Disease (AD). A key limbic region is the fornix located proximal to the ventricles. Given the relatively large voxel size used in most clinical DTI acquisitions, the probability of CSF contamination in the fornix is high, often leading to interruption of tracts due to either a reduction in FA or misdirection due to erroneous eigenvector estimation, particularly in AD where ventricles are enlarged. FLAIR DTI has been used by many investigators to suppress CSF (e.g. [1,2,3,4]) but at the expense of SNR and data acquisition time and to our knowledge, FLAIR DTI is rarely used in clinical studies. Aiming toward eventual quantification of DTI metrics such as FA and tract density in the fornix and other limbic pathways in AD, the objective of this work was to develop a post-processing strategy to correct partial volume effects such that it could be used to analyze existing clinical DTI data.