Comparison of cone beam computed tomography multiplanar reconstruction in the plane of stapes and the lateral semicircular canal for the diagnosis of otosclerosis.

OBJECTIVES: We aimed to compare the diagnostic performance and view-related differences of multiplanar reconstruction (MPR) in the standard radiological Lateral Semicircular Canal (LSC) plane and in the stapes-plane on Cone Beam Computed Tomograhpy (CBCT). METHODS: Six cases and six controls from a prospective cohort of patients undergoing exploratory tympanotomy for suspected otosclerosis with intraoperative confirmation were included. Preoperative CBCT was reconstructed in the LSC and stapes planes and reviewed twice by two neuroradiologists and two otosurgeons. RESULTS: The stapes-plane had a higher perceived image quality (mean = 4.1) compared with the LSC-plane (mean = 3.5) on a 5-point Likert scale. The overall sensitivity and specificity were high for both neuroradiologists and otosurgeons with no difference between the planes in detecting fenestral otosclerosis. The proportion of non-measurable prosthesis length estimates was higher in the LSC-plane than in the stapes-plane (77% and 8%, respectively) while the stapes footplate was estimated significantly thicker in the LSC-plane. We found no plane-related difference in the assessment of otosclerotic focus at either the round window or cochlea. CONCLUSIONS: We found a high sensitivity and specificity for both the LSC and stapes-plane and no MPR-plane dependent differences in the diagnostic performance in fenestral otosclerosis, although the stapes-plane improved the perceived imaging quality and measurement feasibility. Our results highlight the potential clinical utility of CBCT as an adjunct imaging modality and the importance of considering a dedicated reconstruction plane in imaging of patients with suspected otosclerosis.