Development and Evaluation with 4D Flow MR Imaging of a Ventricular Cerebrospinal Fluid Dynamics Phantom Driven by Simulated Lateral Ventricle Wall Pulsation

A controllable phantom is needed to evaluate MR measurements of slow, pulsatile cerebrospinal fluid motion. We developed a ventricular phantom in which a pulsatile pump acts on a closed cavity containing an elastic lateral ventricle model, such that wall deformation drives flow through the downstream ventricular pathway. Four-dimensional flow MRI was performed at 3T and 50 beats/min with nominal bidirectional pump displacement volumes of 0.4-2.0 mL/cycle, corresponding to 1-way syringe settings of 0.2-1.0 mL. Flow was visualized at the foramen of Monro, cerebral aqueduct, bilateral foramina of Luschka, and foramen of Magendie. Regional bidirectional stroke volume and mean velocity increased with pump setting, with the highest velocity in the aqueduct. An exploratory analysis of central-aqueduct at the middle setting, performed in 3 sessions on separate days, yielded a mean cycle-averaged speed of 3.75 ± 0.34 cm/s with a between-session coefficient of variation of 9.1%. This wall-deformation-driven phantom provides a controllable platform for studying pulsatile cerebrospinal fluid motion, with potential applications in the validation of flow-sensitive imaging techniques. Absolute measurement accuracy, physiological equivalence, and reproducibility across all pump settings remain to be established.