Scintigraphic diagnosis of acoustic neurofibromas.

Radioisotope brain scanning gave positive results in 57 out of 68 acoustic neurofibromas in three British neurosurgical centres. Acoustic neurofibromas over 2 cm in diameter may be expected to give a positive scintigraphic result, and tumours of this size also erode the petrous bone. Since most are 3-4 cm in diameter, correlation between the results of petrous radiography and cerebral scintigraphy often permits a specific diagnosis of acoustic neurofibroma to be made. No other radiological investigation may be necessary preoperatively.