Cerebral blood flow measurements in infants using look-locker arterial spin labeling

Purpose: To measure cerebral blood flow (CBF) using Look-Locker arterial spin labeling (ASL) in children under 1 year of age and to investigate the advantages of using subject-specific estimates of ASL model parameters in this population. Materials and Methods: Of 12 scanned infants, we successfully acquired CBF maps in 7 (postmenstrual age: 32 to 78 weeks) using a Look-Locker ASL scheme and both adult literature-derived and subject-specific model parameters. ASL global CBF measurements were compared with independent global CBF measurements obtained in the same scanning session using phase-contrast angiography. Results: Measured global CBF values ranged from 24 to 56 mL/100g/min in the scanned infants, increasing significantly with postmenstrual age (ρ_Spearman = 0.89, P-value = 0.01). Using subject-specific model parameters yielded CBF estimates in significantly better agreement with phase-contrast angiography values (P-value: 0.80) than when standard adult parameters were used (P-value: 0.04). Conclusion: Look-Locker ASL can be used to measure CBF in infants and its accuracy is improved with the use of infant-specific auxiliary parameters, particularly blood and tissue T₁, which were much more variable in the imaged infants in than adults.