Accuracy of 3.0 Tesla magnetic resonance imaging in the diagnosis of intracochlear schwannoma.

Intracochlear schwannomas (ICSs) are rare tumors. The diagnosis of ICS is based on high-resolution magnetic resonance imaging (MRI), which should be used for the accurate determination of the location of tumors. Recent advancements in imaging technologies and software enable the precise regional diagnosis of ICS. We experienced a case of intracochlear schwannoma with a diagnosis of progressive hearing loss and tinnitus. Audiometry revealed severe hearing loss in the right ear with remaining low-frequency hearing. MRI showed an abnormal lesion in the cochlea. Three-dimensional real inversion recovery (3D rIR) and constructive interference in steady state (CISS) MRI revealed the size and shape of the tumor via identification of the cochlear nerve and cochlear fluid space. CISS and 3D rIR sequences provide useful information regarding the boundaries of tumors and the tissues that surround them.