Functional brain imaging with SPECT in normal aging and dementia. Methodological, pathophysiological, and diagnostic...

Area of Science:

• Neurology
• Radiology
• Nuclear Medicine

Background:

• Advancements in instrumentation, radiochemistry, and data analysis have propelled single photon emission computed tomography (SPECT) into a new era for brain imaging.
• The introduction of 99mTc-labeled brain-retained tracers has significantly improved perfusion studies.

Purpose of the Study:

• To review critical methodological issues in SPECT imaging for brain perfusion studies.
• To discuss the diagnostic significance of regional cerebral blood flow (rCBF) deficits in dementia, particularly Alzheimer's disease.
• To explore the potential of SPECT as a screening and monitoring tool in dementia research and clinical practice.

Main Methods:

• Review of methodological aspects including instrumentation, tracers, scanning procedures, and data analysis.
• Analysis of changes in regional cerebral blood flow (rCBF) in normal aging.
• Overview of the topography and significance of focal rCBF deficits in Alzheimer's disease and other dementias.

Main Results:

• SPECT demonstrates high sensitivity and specificity for detecting focal rCBF deficits in Alzheimer's disease, especially when combined with CT findings of medial temporal lobe atrophy.
• SPECT imaging, alongside neuropsychological testing, effectively maps brain dysfunction topography.
• SPECT provides supplemental diagnostic information in the clinical setting.

Conclusions:

• Functional brain imaging with SPECT is a crucial tool for the diagnosis, management, and research of dementia disorders.
• SPECT offers a less expensive and technically simpler alternative to PET for screening and clinical applications in dementia.
• Future applications of SPECT include neuroreceptor studies and treatment monitoring, aiding in patient selection and treatment evaluation.