Air CT cisternography of the cerebellopontine angle

Air CT cisternographies were performed on 13 patients who suspected cerebellopontine angle lesions by neurootological examinations. Out of the 13 patients, 4 had acoustic neurinomas and underwent surgery, 8 had no tumor, and the situation of 1 was not clarified. Polytomography and CT scanning with intravenous contrast enhancement are initial radiological methods in patients with cerebellopontine angle lesions. However, these methods are less reliable than air CT cisternography in the case of a small mass, because they are apt to give more pseudopositive and pseudonegative diagnoses. In the 4 acoustic neurinomas which were demonstrated by air CT cisternograms, only 1 had been suspected of having a cerebellopontine angle tumor after intravenous contrast-enhanced CT. Our results suggest that air CT cisternography is superior to all other diagnostic methods in defining a small acoustic neurinoma. (author)