Evaluating age-associated cerebral blood flow variations in MCA-ASPECTS regions using 3D-ASL.

Background: Cerebral blood flow (CBF) regulation is fundamental to maintaining normal brain function and is known to vary with age. This study aimed to investigate the correlation between age and CBF within specific regions of the Middle Cerebral Artery-Alberta Stroke Project Early Computed Tomography Score (MCA-ASPECTS) framework by quantitatively assessing CBF in healthy individuals.

Methods: This cross-sectional study included healthy participants who underwent a series of imaging protocols, including head magnetic resonance imaging, three-dimensional arterial spin labeling (3D-ASL), and magnetic resonance angiography. CBF values were analyzed across all MCA-ASPECTS regions to establish reference CBF metrics and evaluate interhemispheric discrepancies. Comparisons were made between corresponding ASPECTS regions in the left and right hemispheres and among 10 unilateral ASPECTS regions. Pearson's correlation analysis was used to examine associations between CBF and age.

Results: The study included 22 healthy volunteers. Significant variations in CBF were observed in the bilateral insula, M1, and M4 regions (P < 0.05). Among the MCA-ASPECTS regions, the highest mean CBF values were found in the bilateral M3 regions and the right insula (55.63 ± 6.56, 57.24 ± 7.75, and 57.63 ± 7.97, respectively), while the lowest were observed in the bilateral internal capsule regions (34.15 ± 5.30 and 35.29 ± 5.23, respectively). The left-right brain CBF difference index was highest in the M1 region (x = 0.061 ± 0.038) and lowest in the M2 region (x = 0.022 ± 0.020). Significant differences in CBF were detected across the ten bilateral MCA-ASPECTS regions (P < 0.001), with most area-to-area comparisons showing statistical significance (P < 0.05). CBF demonstrated significant negative correlations with age in the bilateral insula, bilateral M2, the left caudate, and the right M1 regions, with correlation coefficients ranging from - 0.43 to -0.49 (P < 0.05). In contrast, a positive correlation was observed between age and CBF in the right internal capsule region (correlation coefficient = 0.4, P < 0.05).

Conclusions: Automated quantitative assessment of CBF in MCA-ASPECTS regions using 3D-ASL offers significant advantages, including repeatability, practicality, and clinical relevance. This approach facilitates precise evaluation of regional CBF variations and provides a critical foundation for the quantitative application of 3D-ASL in ischemic stroke diagnosis and management.