This study aims to optimize 4D flow MRI of cerebral vessels by reducing scan time while preserving quantitative accuracy. A rigid internal carotid artery phantom with three aneurysms (Elastrat, Switzerland) was scanned on a 3T system using the Siemens BEAT FQ 4D flow sequence. Flow was generated by an MCP-Z pump under steady conditions. Sequences with various acceleration factors, such as reduced spatial resolution, GRAPPA, and partial Fourier, were compared to a fully sampled reference using pointwise velocity correlations (R²), with accuracy defined as at least 90% of the velocity variance explained. Acquisition time was reduced to 21s (20.6-fold). With R2 values between 0.91 and 0.97, the optimized parameter set preserved velocity information with only 23% of the variance remaining unexplained. With simulated cardiac gating (75 bpm), scan time was 4min 27s (24.6-fold reduction). The proposed acceleration framework enables rapid, accurate 4D flow MRI of cerebral vessels for potential neurovascular applications.