Amplified MR assessment of idiopathic Normal Pressure Hydrocephalus Pre-/Post-Shunt Surgery.

Motivation: This study aims to correlate variations in subvoxel displacement magnitudes with ventriculoperitoneal shunt status in patients with normal pressure hydrocephalus (NPH). Goal(s): We sought to evaluate intracranial voxel displacement as a non-invasive surrogate of intracranial compliance for risk assessment in NPH patients using amplified MRI (aMRI), a clinically feasible, cardiac-gated, cine-based method employing Eulerian video magnification to amplify and characterize subvoxel motion. Approach: NPH patients clinically necessitating ventriculoperitoneal shunt (VPS) placement underwent aMRI one-week before and 3 months after VPS surgery. Results: Percentage change in whole brain maximum displacement magnitude pre- and post-shunt surgery was the best predictor of VPS status (p=0.01). Impact: In this pilot study evaluating normal pressure hydrocephalus patients necessitating ventriculoperitoneal shunt (VPS) surgery, derived amplified MRI metrics correlate with VPS status (p=0.01), and may serve as a novel biomarker in assessing functional VPS status in clinical practice.