[Diagnostic value of magnetic resonance imaging in the differential diagnosis of acoustic neuroma and meningiomas of the cerebellopontine angle].

OBJECTIVE

To estimate the diagnostic value of differential diagnostic criteria for acoustic neuromas and meningiomas of the cerebellopontine angle in the use of standard magnetic resonance imaging (MRI) modes.

SUBJECT AND

METHODS

The study enrolled 39 patients aged 54 +/- 8 years who had histologically verified acoustic neuromas (n=26) and meningiomas (n=13) of the cerebellopontine angle. MRI scans were compared in the outline and location of a tumor and its signal intensity and uniformity. The quantitative standardized coefficient of tumor signal intensity values was calculated by dividing of the latter by those of cerebrospinal fluid in the lateral ventricles and pons cerebelli.

RESULTS

The acoustic neuromas and meningiomas of the cerebellopontine angle exhibited differences in indicators, such as a wide base, the rate of penetration into the internal acoustic meatus, and heterogeneous contrast enhancement on T2-weighted images (T2-WI). The adjacent meninges were different in contrast. Neuromas were hyperintense to the pons varolii on T2-WI and had a low standardized coefficient of cerebrospinal fluid (1.73 +/- 0.3) and the pons (0.73 +/- 0.09) on T1-weighted images (T1-WI). Meningiomas were isointense to the pons varolii on T2-WI had a higher standardized coefficient of cerebrospinal fluid (2.23 +/- 0.36) and the pons (0.86 +/- 0.08) on T1-WI. ROC analysis determined the boundary values for the coefficients with the highest specificity.