Low blood flow is the number one brain imaging predictor of Alzheimer's disease.
"Blood flow—low blood flow is the number one brain imaging predictor of Alzheimer's disease." (said at 0:56:00)
Low cerebral blood flow (hypoperfusion, typically assessed via SPECT or arterial spin labeling MRI) is not the leading or "number one" neuroimaging predictor of Alzheimer's disease. In clinical diagnostic frameworks and comparative imaging studies, pathological hallmark imaging (amyloid-beta PET and tau PET), fluorodeoxyglucose (FDG) PET, and structural MRI (such as medial temporal lobe and hippocampal volumetry) are the primary, most accurate imaging biomarkers for Alzheimer's disease. While characteristic patterns of hypoperfusion (particularly in the posterior cingulate and temporoparietal cortices) are observed in Alzheimer's disease and can assist in differential diagnosis or prognostication of mild cognitive impairment, systematic reviews and comparative studies demonstrate that FDG-PET and specific amyloid/tau imaging biomarkers consistently demonstrate higher diagnostic accuracy and predictive power than perfusion imaging.
- contradicts: A comparison of FDG-PET and blood flow SPECT in the diagnosis of neurodegenerative dementi… (International journal of geriatric psychiatry 2014)
"Published studies of SPECT accuracy show that it is a useful tool for differential diagnosis, with sensitivities of 65-85% for diagnosing Alzheimer's disease (AD) and specificities (for other neurodegenerative dementias) of 72-87%. PET studies generally report higher accuracy, with sensitivities of 75-99% for AD and specificities of 71-93%." (abstract, results, passage verified)
pubmedfull study (doi) - contradicts: Systematic review and meta-analysis of diagnostic test accuracy (DTA) studies: the role of… (Annals of palliative medicine 2022)
"The meta-analysis results showed that the sensitivity and specificity of FDG-PET imaging was significantly higher than those of SPECT and MRI imaging, and the differences were statistically significant (P<0.05)." (abstract, results, passage verified)
pubmedfull study (doi) - contradicts: Prognostic Value of A/T/N Biomarkers: Comparing Plasma and Imaging Modalities in Alzheimer… (Clinical nuclear medicine 2025)
"Among 1,614 plasma cohort and 130 imaging subcohort participants, tau markers demonstrated the strongest predictive value... suggesting that combinations of amyloid and tau PET captures the most relevant prognostic information." (abstract, results)
pubmedfull study (doi)