MAGNETIC RESONANCE IMAGING FOR EARLY DETECTION AND DIAGNOSIS OF DEMENTIA DUE TO ALZHEIMER’S DISEASE

Abstract

Background: Alzheimer’s disease (AD) is the most common cause of dementia worldwide and is characterized by progressive neurodegeneration involving the hippocampus, medial temporal structures, association cortices, and related networks. Magnetic resonance imaging (MRI) enables in-vivo visualization of these structural changes and is increasingly recognized as a core biomarker modality for early detection and diagnosis of AD.

Objective: To evaluate MRI-based structural biomarkers for early detection and diagnosis of dementia due to Alzheimer’s disease and to analyze their relationship with patient age.

Methods: A cross-sectional study was conducted on 48 patients clinically suspected of having dementia due to AD and referred for brain MRI at tertiary care hospitals in Lahore, Pakistan. Standard MRI protocols (1.5T/3T) included T1-weighted, T2-weighted, FLAIR, diffusion-weighted imaging, and volumetric sequences. Structural biomarkers assessed were hippocampal atrophy, entorhinal cortex atrophy, temporal, parietal, frontal and cingulate gyrus atrophy, cortical thinning, and ventricular enlargement. Descriptive statistics were generated, and non-parametric tests (Mann–Whitney U) were used to assess associations between age and MRI findings.

Results: The mean age of participants was 69.5 ± 10.1 years (range: 55–85); 54.2% were male. Hippocampal atrophy was present in 81.3% of patients, temporal lobe atrophy in 79.2%, ventricular enlargement in 77.1%, entorhinal cortex atrophy in 66.7%, frontal and cingulate gyrus atrophy each in 60.4%, parietal lobe atrophy in 58.3%, and cortical thinning in 45.8%. None of the MRI biomarkers showed a statistically significant association with age (p > 0.05 for all comparisons), indicating that the structural abnormalities predominantly reflected disease-related neurodegeneration rather than physiological aging.

Conclusion: MRI is a highly sensitive modality for detecting characteristic structural patterns of Alzheimer’s disease, particularly medial temporal lobe atrophy and ventricular enlargement. The high prevalence of these biomarkers and their lack of association with age support MRI as a powerful tool for early diagnosis and staging of AD. Routine incorporation of MRI, including medial temporal atrophy assessment, is recommended in the diagnostic workup of patients presenting with early cognitive complaints.