3.3 Imaging findings
MRI was performed in all 10 patients revealing the tumors ranging from 0.7 cm to 2.7 cm, with a mean size of 1.44 ± 0.63 cm. Figure 1b demonstrated the axial cranial MRI of these patients. According to the Koos grading standard, there were 5 grade I (intracanalicular) tumors, 3 grade II tumors and 2 grade III tumors. The audiograms of patients with grades I–III tumor are shown in Figure 2. There was no obvious relation between tumor size and hearing loss with regard to the audiometric pattern. We also conducted correlation analyses between tumor size and grade of hearing loss and configuration of audiograms. There was no significant correlation between tumor size and grade of hearing loss (r = 0.1136, P = 0.7533; Spearman’s rank correlation test). Tumor size and configuration of audiograms were also unrelated (r =0.0528, P =0.8831; Spearman’s rank correlation test).