Morphologic (CT) and functional (rCBF-SPECT) correlates in Alzheimer's disease

Area of Science:

• Neurology
• Radiology
• Neuroimaging

Background:

• Alzheimer's disease (AD) is a progressive neurodegenerative disorder.
• Assessing structural and functional brain changes is crucial for AD diagnosis and monitoring.

Purpose of the Study:

• To investigate the correlation between structural changes (atrophy) on computed tomography (CT) and functional changes (regional cerebral blood flow - rCBF) using single photon emission computed tomography (SPECT) in patients with probable Alzheimer's disease.
• To evaluate the relationship between neuroimaging findings and cognitive performance.

Main Methods:

• 35 patients with probable AD underwent both CT and SPECT scans.
• Image analysis involved scoring for structural atrophy (CT) and perfusion deficits (SPECT).
• Spearman's rank correlation coefficients were used to analyze correlations between CT and SPECT scores, and between imaging scores and cognitive assessments (Mini-Mental State Examination and CAM-COG).

Main Results:

• A high concordance was observed between CT-detected atrophy and SPECT-detected perfusion deficits (33/35 patients).
• Regional CT and SPECT scores did not significantly correlate, but total and left hemisphere scores showed fair correlations.
• Perfusion scores demonstrated highly significant correlations with cognitive performance, whereas CT scores showed lower correlations.

Conclusions:

• The relationship between structural and functional brain changes in Alzheimer's disease is complex.
• Regional cerebral blood flow (rCBF) assessed by SPECT is a reliable indicator of cognitive deficits in Alzheimer's disease, potentially more so than structural changes alone.