RADIATION-INDUCED MENINGIOMA CONCEALED BY SHUNT VALVE ARTIFACT : CASE REPORT. Commentary

OBJECTIVE: Ventricular shunting is a common neurosurgical procedure. Metal-containing shunt components can cause artifacts on magnetic resonance imaging (MRI), obscuring visualization of the surrounding tissue. We present the case of a radiation-induced meningioma growing around a ventricular catheter that was not noted at an early stage as a result of artifact from an overlying shunt. CLINICAL PRESENTATION: We present the case of a 27-year-old survivor of a childhood medulloblastoma who required ventriculoperitoneal shunting as a consequence of hertreatment. As a result of radiation-induced meningiomas that developed in adolescence, the patient was screened biennially via contrasted MRI. Her most recent imaging revealed a new meningioma at the edge of the MRI artifact associated with the shunt valve. A contrasted computed tomographic scan demonstrated a large meningioma with mass effect on the surrounding brain. INTERVENTION: Complete surgical resection of the meningioma was obtained. The ventricular catheter was preserved and the shunt valve replaced with a newer system that is reported to generate less magnetic artifact. CONCLUSION: Artifact from shunt valves or other implanted metallic devices obscures the surrounding tissues on MRI. Patients with significant artifact who are at higher risk for development of intracranial pathology may benefit from periodic imaging through alternate modalities that are not susceptible to magnetic artifact.