Association of Radiologic Findings of Otosclerosis Using Photon-Counting Computed Tomography With Hearing

OBJECTIVE: To examine the association of extent of otosclerotic plaque using high-resolution photon-counting computed tomography (PCCT) with hearing and surgical outcomes. STUDY DESIGN: Historical cohort. SETTING: Large academic center. PATIENTS: Patients with otosclerosis who completed PCCT imaging at time of initial evaluation. INTERVENTIONS: Observation, surgery. MAIN OUTCOME MEASURES: Audiometric data. RESULTS: A total of 53 ears were eligible for study. The mean age at PCCT was 51 years (SD: 14). The mean extent of oval window otosclerotic plaque measured in radial degrees was 112 (SD: 65) and the mean otosclerotic depth was 1.6mm (SD: 0.6). The mean air-bone gap pure-tone average was 18 dB (SD: 12) and the mean Carhart degree was 9 dB (SD: 10). The radial degrees of oval window extent were not significantly associated with air-bone gap (correlation coefficient: 0.14; P =0.3) or Carhart degree (correlation coefficient: 0.04; P =0.8). Likewise, otosclerotic plaque depth was not significantly associated with air-bone gap (correlation coefficient: -0.19; P =0.2) or Carhart degree (correlation coefficient: -0.08; P =0.6). After PCCT, 22 ears underwent surgery. In this subset, oval window extent and plaque depth were not significantly associated with the postoperative changes in air-bone gap or high-frequency thresholds. CONCLUSIONS: Despite enhanced visualization of subtle abnormalities with PCCT imaging, the extent of oval window otosclerotic plaque, measured in angular degrees and depth, was not associated with hearing loss at time of initial evaluation or postoperative audiologic changes in patients with otosclerosis.