2.3 Imaging and audiology
There were a total of 156 patients; 25 patients underwent revision mastoidectomy due to persistent discharge from the ear after a previous mastoidectomy. All of the patients’ CT scans were reviewed. Seven cases of EC-LSC were identified from the CT scans. The preoperative CT image characteristics, intraoperative observations of lesions, and postoperative hearing thresholds and complications of these seven patients were evaluated to determine the clinical characteristics of EC-LSC.
Audiological parameters using three frequencies, 0.5, 1 and 2 kHz, were assessed pre and postoperatively. The Paired T test was used to compare the preoperative and postoperative changes of the hearing threshold. All analyses were performed using GraphPad Prism (version 5). Statistical significance was set at a two-tailed P <.05.