A diffusion kurtosis MRI signature of subjective cognitive decline

• DOI: 10.1002/alz.091495
• Publication Date: 2025-01-09T12:12:27Z
• Authors: Ryn Flaherty; Yu Veronica Sui; Mu Li; Ana Ardelean; Henry Rusinek; Arjun V. Masurkar; Mariana Lazar
• Keywords: Kurtosis; Cognitive Decline

Abstract Background Diffusion weighted imaging (DWI) of brain white matter is better at predicting future cognitive decline and medial temporal lobe atrophy than cerebrospinal fluid biomarkers in subjective (SCD) 1 . However, few studies have investigated gray DWI SCD, despite the importance regional changes as a biomarker for Alzheimer’s Disease related dementias. Method 316 cognitively normal participants from Cam‐CAN 2 (123 SCD) older 55 were included analysis. Participants placed SCD group if they endorsed problems with their memory. Imaging data was collected on 3T Siemens Trio scanner 0, 1000 2000 s/mm b‐values 30 gradient directions, processed using MrTrix3, PyDesigner, AMICO to apply diffusion tensor (DTI), kurtosis (DKI), neurite orientation density dispersion (NODDI) models. FreeSurfer T1w T2w images used segment subcortical cortical regions (Figure 1B&C), then calculate volume thickness. Segmentations also registered generate averages metrics. Uncorrected p<0.05 according Wilcoxon tests considered significant. Result The metric most differences fractional anisotropy (KFA) DKI, an indicator structural complexity. KFA significantly lower 17 84 regions, including hippocampus 2‐3B). DTI showed reduced 2‐3C) increased mean diffusivity 2‐3D) but fewer KFA. NODDI free water 2‐3E), 2‐3F), 3G) SCD. Volume thickness higher 5 3 2‐3A). Only hippocampus. Conclusion more sensitive consistent volume, thickness, all other This may indicate signature across whole matter. Selnes P, Aarsland D, Bjornerud A, et al. J Alzheimers Dis. 2013;33(3):723‐36. Shafto MA, Tyler LK, Dixon M, BMC Neurol. 2014;14(1):1‐25.