Decreased quantitative transport mapping velocity in the middle cerebral artery–supplied temporal lobe in Alzheimer's disease

Abstract INTRODUCTION Reduced blood perfusion has been observed in patients with Alzheimer's disease (AD), but the patterns of blood perfusion changes during AD progression remain insufficiently explored. METHODS Quantitative transport mapping (QTM) is a novel biophysical modeling‐based method for quantifying blood perfusion velocity. In this study, we examined regional changes in perfusion velocity throughout AD progression by combining QTM velocity measurements with Granger causality analysis using cross‐sectional data, as a secondary and exploratory analysis following our previous QTM work, aiming to offer a comprehensive view of the QTM velocity patterns based on the arterial territories. RESULTS Reduced QTM velocity was observed in the middle cerebral artery (MCA)–supplied regions for patients with mild cognitive impairment. The MCA‐supplied temporal lobe is a driving region of QTM velocity changes in other brain regions. DISCUSSION The temporal lobe supplied by the MCA is the earliest brain region to exhibit changes in QTM velocity, indicating its potential as an early biomarker for AD diagnosis. Highlights Quantitative transport mapping (QTM) velocity was significantly reduced in the middle cerebral artery (MCA)–supplied regions among patients with mild cognitive impairment, compared to cognitively normal individuals. The temporal lobe supplied by the MCA is a driving region of QTM velocity changes in other brain regions. The temporal lobe supplied by the MCA has great potential as an early biomarker for AD diagnosis.