MR approaches in neurodegenerative disorders

Area of Science:

• Neuroimaging
• Neurology
• Radiology

Background:

• Neurodegenerative diseases involve neuron degeneration, leading to brain dysfunction and death.
• Alzheimer's disease (AD) is the most common, affecting millions globally, with dementia with Lewy bodies (DLB) being the second most prevalent.
• Current definitive diagnosis relies on post-mortem neuropathological assessment of protein deposits.

Purpose of the Study:

• To review Magnetic Resonance (MR)-based measurements for diagnosing neurodegenerative diseases.
• To compare MR findings in Alzheimer's disease (AD) and dementia with Lewy bodies (DLB).
• To explore the potential of advanced MR techniques and multimodal approaches for improved diagnosis.

Main Methods:

• Conventional T1-weighted (T1w) MRI to assess structural brain changes, particularly medial temporal lobe atrophy.
• Diffusion tensor imaging (DTI) to evaluate white matter microstructure integrity.
• Atrophy-corrected Magnetic Resonance Spectroscopy (MRS) to assess neuronal density and metabolic alterations.

Main Results:

• T1w MRI reveals significant medial temporal lobe atrophy in AD, often preserved in DLB, aiding clinical diagnosis.
• DTI shows widespread microstructural changes in white matter, with subtle differences suggested between AD and DLB.
• MRS indicates reduced healthy neuron density in affected brain regions, correlating with perfusion changes and protein deposits.

Conclusions:

• MR imaging techniques provide valuable insights into structural and microstructural brain changes in AD and DLB.
• Current MR methods show limitations in detecting early disease stages and achieving non-invasive diagnostic certainty.
• Future advancements may involve combining MR with other modalities like PET and utilizing AI for comprehensive data analysis.