Computed tomography in the differential diagnosis of cerebellopontine angle tumors

27 cases of cerebellopontine (CP) angle tumor have been discovered in the Nagoya University Hospital and its affiliated hospitals since the introduction of the CT scanner. Out of the 27 cases, there are 18 cases acoustic neurinoma, 6 of meningioma, 2 of epidermoid, and 1 of astrocytoma. EMI 1000, EMI 1010, HITACHI, and ACTA scanner were used in both hospitals. All the acoustic neurinoma showed low or iso density on the plain CT picture and clear contrast enhancement. 13 cases showed a homogeneous high density, while 4 had a ring-like high density. A ring-like high density was observed exclusively in the large tumor (more than 3 cm in diameter). All the cases of meningioma appeared as a high-density mass on the plain CT and were well enhanced. On the contrary, two epidermoid cases showed a clear, homogeneous low density and no contrast enhancement. (author)