Magnetic resonance imaging-related programmable ventriculoperitoneal shunt valve setting changes occur often

Area of Science:

• Neurosurgery
• Radiology
• Biomedical Engineering

Background:

• Programmable ventriculoperitoneal (VP) shunts are used to manage cerebrospinal fluid imbalances.
• MRI scans are often required for patients with VP shunts, necessitating evaluation for valve setting changes.

Purpose of the Study:

• To determine the incidence of inadvertent, MRI-related setting changes in programmable VP shunt valves.

Main Methods:

• Retrospective cohort study of 156 patients with programmable VP shunts undergoing 210 MRI examinations (2015-2018).
• Analysis of pre- and post-MRI skull radiographs to assess valve setting changes.
• Statistical analysis (chi-square test) to identify factors associated with setting changes, including valve type and MRI magnetic field strength.

Main Results:

• An MRI-related programmable VP shunt valve setting change rate of 56.7% was observed.
• Higher magnetic field strength (p=0.03) and Medtronic Strata™ valves (p<0.0001) were associated with significantly higher rates of setting changes compared to Codman Hakim™ valves.

Conclusions:

• Inadvertent MRI-related shunt valve setting changes are common, especially in valves lacking a locking mechanism.
• Manual reprogramming of valves after MRI, instead of pre- and post-MRI radiographs, is suggested to reduce radiation exposure and costs.
• Manufacturers should consider incorporating locking mechanisms into VP shunt valve designs to minimize unintended setting alterations.