In a series of 571 vestibular schwannomas (VS) operated on in the period 1976-1992, via the translabyrinthine approach, 23 tumours (4 per cent) from 23 patients were radiologically, peroperatively and histologically identified as cystic VS. Neuroimaging examinations (CT and MRI) revealed 15 tumours (2.6 per cent) with extracystic formations and in eight cases (1.4 per cent) intratumoural cysts. In 15 cases (65 per cent), tumours were located extracanalicularly with no involvement of the internal auditory canal (IAC). The extracanalicular tumour extension including the cystic elements ranged between 10 and 60 mm with a mean of 45 mm. In eight cases out of 23 (35 per cent) other diagnostic possibilities such as trigeminal schwannoma, epidermoid cyst and meningioma were proposed at the primary evaluation. Deformation, displacement and/or impression of the fourth ventricle was demonstrated in 17 cases (74 per cent). Three patients (13 per cent) had obstructive hydrocephalus which demanded shunt insertion. Residual tumour was detected in two patients (9 per cent). Growth rate in four cases was more than 10 times higher when compared to the annual growth rate of noncystic VS. The results of this study provide data on cystic VS attenuation demonstrated by CT or MRI which may be valuable in neuroradiological diagnosis of these cystic lesions and emphasizes that the wait-and-see policy should not be applied to the cystic variant of VS.

Cystic vestibular schwannomas: neuroimaging and growth rate.

Acoustic neuroma: Assessment and management

Imaging of Acoustic Neuromas

Effects of contrast agent on water suppression and shimming of kidney single-volume proton MR spectroscopy at 3.0T.

The three original groups participating in our study used the EMI Mark I scanner from 1975 to the middle of 1977 and the EMI CT 1010 scanner after mid-1977. The Siemens Somatom DR has been used in Augsburg and Berlin since 1983, and the Philips Tomoscan CT 350 in Mainz since mid-1986.

Technique of CT and MR Examinations

The early results of the use of the MR specific contrast medium gadolinium-DTPA in 40 patients with intracranial tumours are reported. Optimal pulse sequences, contrast dose and timing are discussed. The relationship between the blood-brain barrier and contrast distribution within tumour tissue is elaborated. The clinical significance of the application of contrast agents in the diagnosis of brain tumours is evaluated.

[Contrast media in magnetic resonance tomography. A review. 2. Biological basis, research technic and clinical application of gadolinium-DTPA in the diagnosis of intracranial tumors].

W. Schorner

Papers

[Contrast media in magnetic resonance tomography. A review. 2. Biological basis, research technic and clinical application of gadolinium-DTPA in the diagnosis of intracranial tumors].