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.