What can DTI tell about early cognitive impairment? - Differentiation between MCI subtypes and healthy controls by

Gyula Gyebnár1, Ádám Szabó1, Enikő Sirály2

  • 1Magnetic Resonance Research Centre, Semmelweis University, Budapest, Hungary.

Insights

Diffusion tensor imaging (DTI) using diffusion-weighted MRI (DWI) can differentiate subtypes of mild cognitive impairment (MCI). DTI metrics aid in the early detection of Alzheimer Disease (AD) and other dementias.

Area of Science:

  • Neuroimaging
  • Neurology
  • Radiology

Background:

  • Mild cognitive impairment (MCI) is a precursor to dementia, with amnestic MCI (aMCI) having a higher conversion rate to Alzheimer Disease (AD).
  • Differentiating MCI subtypes is crucial for early diagnosis and intervention.
  • Diffusion-weighted MRI (DWI) and diffusion tensor imaging (DTI) offer insights into white matter integrity.

Purpose of the Study:

  • To investigate the utility of DTI metrics in distinguishing between aMCI, non-amnestic MCI (naMCI), and healthy controls.
  • To explore the relationship between DTI findings and cognitive performance.
  • To assess the potential of DTI in improving the diagnostic accuracy of MCI subtypes.

Main Methods:

  • Acquisition of high-resolution 3D T1-weighted and DWI images at 3T from patients with aMCI (n=18), naMCI (n=20), and controls (n=27).
  • Processing of imaging data using ExploreDTI and SPM software.
  • Voxel-wise and region of interest (ROI) analyses of fractional anisotropy (FA) and mean diffusivity (MD) using ANCOVA, with logistic regression for diagnostic discrimination.

Main Results:

  • Higher mean diffusivity (MD) in aMCI compared to controls and naMCI, particularly in temporal lobe grey and white matter regions.
  • Lower fractional anisotropy (FA) in white matter regions, such as the left Cingulum, in aMCI.
  • Significant correlations between DTI metrics and cognitive functions (verbal fluency, memory).
  • Combined FA of the crus of fornix and grey matter volumetry improved aMCI discrimination from naMCI.

Conclusions:

  • DTI metrics can effectively differentiate between MCI subtypes and healthy individuals.
  • DTI analysis provides valuable information for the preclinical detection of AD.
  • DTI may aid in the early identification of non-Alzheimer dementias.