[Magnetic resonance tomography in acoustic neurinomas]

The possibilities of MR and CT were compared in respect of neurinomas of the acoustic nerve (n. acusticus). The comparison showed that MR detection of tumours in the posterior of the cranial cavity is the more sensitive method, especially in respect of neurinomas of the acoustic nerve, although CT enables the use of the small-level technique with or without the addition of a contrast substance, as well as the application of pneumocisternography. The sensitivity of MR can be increased further by adding a contrast medium. Whereas in diagnosis of extrameatal neurinomas of the n. acusticus, CT and MR are of equal value, MR shows substantial advantages over CT in the diagnosis of intrameatal tumours (without enlargement of the inner ear canal). The same holds true for very small tumours of up to 1 mm diameter, the visualisation of which is greatly facilitated by the multidimensional possibilities of MR and by the administration of a contrast medium.