Neonatal Brain Perfusion Imaging Protocol

The PASL images were acquired with perfusion model of PICORE Q2T from a 32-channel coil 3T Siemens scanner using the following parameters: bolus time TI₁=700ms, inversion time TI =1800ms, TR/TE=2600/14ms, 14 slices, FOV=200×200mm, 64×64 matrix, voxel size=3.1×3.1×6.0mm³, flip angle=90°, 45 label/control image pairs. The cerebral blood flow (CBF) map was computed from the pulsed PASL images with a single-compartment model[18 (link)] with image preprocessing by ASL data processing toolbox (ASLtbx)[19 (link)]. The parameters utilized in calculating the CBF map were: The blood-brain partition coefficient λ = 1.10 mL/g for neonates[20 (link)], T_1b = 1825ms and T_2b = 191ms for neonates[21 (link)], labeling efficiency α = 0.98 for PASL[18 (link)]. The relaxed equilibrium magnetization M_0b was calculated on cerebrospinal fluid (CSF), white matter (WM), and gray matter (GM) separately from the proton density-weighted image, with the signal ratios of the tissue type being R_CSF = 0.87, R_WM = 1.19, R_GM = 0.98 [22 ] and T_2CSF = 250ms, T_2WM = 222 ms, T_2GM = 143 m [23 (link)] used for neonates.