The Accuracy of Computed Tomography in Internal Acoustic Canal Tumors

Abstract

To evaluate the accuracy of computed tomography in the diagnosis of internal acoustic canal tumors. Fifty-one patients who admitted with the complaints of vertigo, tinnitus, hearing loss underwent contrast enhanced computed tomography examination of temporal bone with the suspicion of internal acoustic canal pathology. The mean age of the patients was 47. Magnetic resonance imaging confirmed tumoral pathology in 12 of 28 patients whose computed tomography examinations suggested tumor in the acoustic canal. The dimensions of the tumors range between 4-18 mm (mean: 7 mm). The remaining 6 patients were evaluated as normal. Computed tomography disclosed no differrence between the diameters of right and left canals in 17 of 39 patients who were found to have no tumor on magnetic resonance imaging, whereas a 1 to 3 mm (mean: 1.95 mm) difference was found at the canal diameters by computed tomography in the remaining (22 patients). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy rate of computed tomography in diagnosis of internal acoustic canal tumors were 100%, 84.6%, 66.6%, 100%, and 88.2%, respectively. Computed tomography has a high accuracy in diagnosis of internal acoustic canal tumors. Although a diameter difference more than 2 mm between right and left canals suggests tumoral pathology, it is not sufficient for diagnosis alone.