Predicting conversion to dementia in mild cognitive impairment by volumetric and diffusivity measurements of the...

Area of Science:

• Neuroimaging
• Neurology
• Biomedical Engineering

Background:

• Mild cognitive impairment (MCI) is a transitional stage between normal aging and dementia.
• Accurate prediction of MCI conversion to dementia is crucial for timely intervention.
• Diffusion tensor imaging (DTI) offers insights into white matter microstructure.

Purpose of the Study:

• To investigate the utility of diffusion tensor imaging (DTI) in predicting dementia conversion in amnestic MCI.
• To compare the predictive power of hippocampal mean diffusivity (MD) and hippocampal volumes for dementia conversion.

Main Methods:

• Prospective study involving 13 amnestic MCI patients.
• Baseline DTI was used to measure left hippocampal mean diffusivity (MD).
• Hippocampal volumes, verbal memory, and MMSE scores were also assessed.
• Patients were followed clinically for a mean of 1.12 years.

Main Results:

• MCI patients who converted to dementia (6/13) exhibited slightly elevated left hippocampal MD at baseline.
• No significant differences in hippocampal volumes, verbal memory, or MMSE were found between converters and stable MCI patients.
• Hippocampal diffusivity demonstrated superior predictive ability for dementia conversion compared to hippocampal volumes.

Conclusions:

• Elevated hippocampal mean diffusivity at baseline may indicate an increased risk of dementia conversion in MCI.
• DTI-derived hippocampal diffusivity is a promising biomarker for predicting dementia progression in MCI.
• Hippocampal diffusivity offers a more sensitive marker for predicting dementia conversion than volumetric measures.