Evaluating the role of magnetic resonance imaging scans in the surgical management of acoustic neuromas

Objective: To assess the reliability of magnetic resonance imaging (MRI) in predicting the size and position of an acoustic neuroma, with particular reference to the intracanalicular portion. Study Design: Prospective study comparing the position of the tumor in the internal auditory canal on fast spin-echo MRI with the actual position measured intraoperatively, Methods: The study was performed in a tertiary referral neurotology center, encompassing both the public and private health care systems, Fifteen consecutive patients admitted for acoustic neuroma removal via the translabyrinthine approach were studied. The main outcome measure was tumor position in the internal auditory canal expressed in millimeters, accurate to the nearest 0.5 nun. Results: The fast spin-echo MRI was accurate within an error of 1 mm in predicting the lateral extent of the tumor in the internal auditory canal. Conclusion: Fast spin-echo MRI can accurately predict the lateral extent of an acoustic neuroma and allow accurate planning of the surgical approach.