Transorbital sonography and MRI reliability to assess optic nerve sheath diameter in idiopathic intracranial hypertension.

Background And Purpose: The purpose of this study was to evaluate the performance of magnetic resonance imaging (MRI) in measuring the optic nerve sheath diameter (ONSD) compared to the established method transorbital sonography (TOS) in patients with idiopathic intracranial hypertension (IIH).

Methods: Twenty-three patients with IIH were prospectively included applying IIH diagnostic criteria. All patients received a lumbar puncture with assessment of the cerebrospinal fluid (CSF) opening pressure to assure the IIH diagnosis.