Multiparametric estimation of brain hemodynamics with MR fingerprinting ASL

Purpose: Assessment of brain hemodynamics without exogenous contrast agents is of increasing importance in clinical applications. This study aims to develop an MR perfusion technique that can provide noncontrast and multiparametric estimation of hemodynamic markers. Methods: We devised an arterial spin labeling (ASL) method based on the principle of MR fingerprinting (MRF), referred to as MRF-ASL. By taking advantage of the rich information contained in MRF sequence, up to seven hemodynamic parameters can be estimated concomitantly. Feasibility demonstration, flip angle optimization, comparison with Look-Locker ASL, reproducibility test, sensitivity to hypercapnia challenge, and initial clinical application in an intracranial steno-occlusive process, Moyamoya disease, were performed to evaluate this technique. Results: Magnetic resonance fingerprinting ASL provided estimation of up to seven parameters, including B₁^*, tissue T₁, cerebral blood flow (CBF), tissue bolus arrival time (BAT), pass-through arterial BAT, pass-through blood volume, and pass-through blood travel time. Coefficients of variation of the estimated parameters ranged from 0.2 to 9.6%. Hypercapnia resulted in an increase in CBF by 57.7%, and a decrease in BAT by 13.7 and 24.8% in tissue and vessels, respectively. Patients with Moyamoya disease showed diminished CBF and lengthened BAT that could not be detected with regular ASL. Conclusion: Magnetic resonance fingerprinting ASL is a promising technique for noncontrast, multiparametric perfusion assessment. Magn Reson Med 78:1812–1823, 2017.