[Magnetic resonance imaging and CT diagnosis of small acoustic neuromas in the internal auditory canal].

The MRI findings of 6 small acoustic neuromas proved by surgery and pathology were analyzed in detail and compared with CT air cisternography. The MRI features of small acoustic neuromas include that small lesions produce thickening of the nerve or partial or entire filling of the internal auditory canal. In T1-weighted images, the tumor is of higher signal intensity than CSF, but is the same as the brain in T 2-weighted images, the tumor is brighter than the brain. MRI makes possible the diagnosis of small acoustic neuromas without subjecting the patients to invasive procedures or exposing them to X-radiation. Comparing MRI with CT air cisternography, we conclude that MRI is more convenient than CT and causes no postoperative complications.