Connectome-derived diffusion characteristics of the fornix in Alzheimer's disease

Publication date: 2018Source: NeuroImage: Clinical, Volume 19Author(s): Rodrigo D. Perea, Jennifer S. Rabin, Megan G. Fujiyoshi, Taylor E. Neal, Emily E. Smith, Koene R.A. Van Dijk, Trey HeddenAbstractThe fornix bundle is a major white matter pathway of the hippocampus. While volume of the hippocampus has been a primary imaging biomarker of Alzheimer's disease progression, recent research has suggested that the volume and microstructural characteristics of the fornix bundle connecting the hippocampus could add relevant information for diagnosing and staging Alzheimer's disease. Using a robust fornix bundle isolation technique in native diffusion space, this study investigated whether diffusion measurements of the fornix differed between normal older adults and Alzheimer's disease patients when controlling for volume measurements. Data were collected using high gradient multi-shell diffusion-weighted MRI from a Siemens CONNECTOM scanner in 23 Alzheimer's disease and 23 age- and sex-matched control older adults (age range = 53–92). These data were used to reconstruct a continuous fornix bundle in every participant's native diffusion space, from which tract-derived volumetric and diffusion metrics were extracted and compared between groups. Diffusion metrics included those from a tensor model and from a generalized q-sampling imaging model. Results showed no significant differences in tract-derived fornix volumes but did show altered diffusion metrics within tissue classif...

Source: NeuroImage: Clinical - July 10, 2018 Category: Radiology Source Type: research