Programmable shunt valve stability after MRI: a 2-year institutional experience across valve types and field strengths.

Abstract

Objective: Programmable cerebrospinal fluid (CSF) shunt valves permit noninvasive adjustment of opening pressure but remain vulnerable to inadvertent setting changes when exposed to magnetic fields. This study evaluated the incidence, direction, and clinical significance of MRI-associated setting changes across six contemporary programmable valve models at both 1.5-T and 3-T field strengths.

Methods: All brain MRI scans performed between October 2023 and October 2025 in patients with cranially implanted programmable valves at a single tertiary pediatric center were prospectively documented using a standardized pre- and post-MRI valve-check protocol. Valve type, magnet strength, and setting changes were recorded, and statistical analyses incorporated Fisher's exact testing and mixed-effects logistic regression to account for repeated scans.

Results: A total of 240 MRI examinations were performed in 87 patients. Overall, 64/240 scans (26.7%) resulted in valve setting changes, with the highest rates occurring in Medtronic Strata valves (28/38, 73.7%), followed by Sophysa Polaris (21/68, 30.9%), Certas Plus (14/115, 12.2%), and proGAV (1/10, 10.0%). No setting changes occurred in Strata MR (0/3) or proGAV 2.0 (0/6) valves. Two valves were non-programmable during assessment. After adjustment for valve type and clustering by patient, magnet strength was not independently associated with valve change. No adverse neurological outcomes occurred.

Conclusions: MRI-related setting changes remain common in certain programmable valves despite newer designs. Brand is the dominant factor, whereas MRI strength alone does not predict risk. Routine pre- and post-MRI valve checks are recommended for all programmable valves.