A patient presents with acoustic neuroma (vestibular schwannoma). Which MRI sequence is the gold standard for its detection, and what does the tumor characteristically appear as?

• A T1-weighted MRI — hyperintense mass in the CPA without contrast
• B T2 FLAIR — dark mass suppressing CSF signal in the CPA
• C Diffusion-weighted imaging (DWI) — restricted diffusion mass in the CPA cistern
• D Gadolinium-enhanced T1 MRI — homogeneously or heterogeneously enhancing mass at the CPA centered on the IAC ✓

Explanation

Gadolinium-enhanced T1-weighted MRI is the gold standard for diagnosing acoustic neuroma (vestibular schwannoma). The tumor appears as an enhancing mass at the cerebellopontine angle, typically with an ice-cream cone or mushroom shape centered on the internal auditory canal, with the widened IAC creating the pathognomonic 'trumpet' appearance. Smaller intracanalicular tumors may only be visible on enhanced T1 or heavily T2-weighted (FIESTA/CISS) sequences showing filling defect in the CSF-filled IAC. DWI restriction is a feature of epidermoid cysts, not schwannomas.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.