Sensitivity of High-Resolution Computed Tomography in Otosclerosis Patients undergoing Primary Stapedotomy

Comparative study of the sensitivity of ultra-high-resolution CT and high-resolution CT in the diagnosis of isolated fenestral otosclerosis

PURPOSE

To compare the diagnostic sensitivity of ultra-high-resolution computed tomography (U-HRCT) and HRCT in isolated fenestral otosclerosis (IFO).

METHODS

A retrospective analysis was conducted on 85 patients (85 ears) diagnosed with IFO between October 2020 and November 2022. U-HRCT (0.1 mm thickness) was performed for 20 ears, HRCT (0.67 mm thickness) for 45 ears, and both for 20 ears. The images were evaluated by general radiologists and neuroradiologists who were blinded to the diagnosis and surgical information. The diagnostic sensitivity of U-HRCT and HRCT for detecting IFO was compared between the two groups.

RESULTS

Excellent inter-observer agreement existed between the two neuroradiologists (Cohen's κ coefficient 0.806, 95% CI 0.692-0.920), with good agreement between the general radiologists (Cohen's κ coefficient 0.680, 95% CI 0.417-0.943). U-HRCT had a sensitivity of 100% (40/40 ears) for neuroradiologists and 87.5% (35/40 ears) for general radiologists, significantly higher than HRCT (89.2% [58/65 ears] for neuroradiologists; 41.5% [27/65 ears] for general radiologists) (p = 0.042, p' < 0.000). General radiologists' sensitivity with HRCT was significantly lower compared to neuroradiologists (p < 0.000), but no significant difference was observed when general radiologists switched to U-HRCT (p = 0.152). Among the 20 ears that underwent both examinations, U-HRCT detected lesions smaller than 1 mm in 5 ears, whereas HRCT's sensitivity for neuroradiologists was 40% (2/5 ears), significantly lower than for lesions larger than 1 mm (93.3%, 14/15 ears, p = 0.032).

CONCLUSION

U-HRCT exhibits higher sensitivity than HRCT in diagnosing IFO, suggesting its potential as a screening tool for suspected otosclerosis patients.

CRITICAL RELEVANCE STATEMENT

Ultra-high-resolution computed tomography has the potential to become a screening tool in patients with suspected otosclerosis and to bridge the diagnostic accuracy gap between general radiologists and neuroradiologists.

KEY POINTS

• U-HRCT exhibits higher sensitivity than HRCT in the diagnosis of IFO. • U-HRCT has a significant advantage in the detection of less than 1 mm IFO. • U-HRCT has the potential to be used for screening of patients with suspected otosclerosis.

Missed Radiological Diagnosis of Otosclerosis in High-Resolution Computed Tomography of the Temporal Bone-Retrospective Analysis of Imaging, Radiological Reports, and Request Forms

Objectives: Several studies reported low detection rates of otosclerosis in high-resolution computed tomography (HRCT), especially when the scans were reviewed by non-specialized general radiologists. In the present study, we conducted a retrospective review of the detection of otosclerosis in HRCT by general radiologists and the impact of inadequately filled radiological request forms on the detection rate. Methods: Retrospective analysis of hospital records, HRCT reports, and radiological referral notes of 40 patients who underwent stapedotomy surgery for otosclerosis. HRCT imaging data sets were retrospectively reviewed by a blinded experienced neuroradiologist, whose reading served as the gold standard. Results: General radiologists reading HRCT scans had an overall detection rate of otosclerosis of 36.1% in this cohort (13 of 36 available HRCT reports). The neuroradiologist had a much higher detection rate of 82.5% (33 of 40 cases). Interobserver agreement between the general radiologists and the subspecialist neuroradiologist was poor (Cohen’s kappa κ = 0.26). General radiologists missed the diagnosis in 15 of the 33 CT-positive scans, corresponding to a missed diagnosis rate of 45.4%. There was a highly significant association between a missed diagnosis and the lack of an explicitly mentioned clinical suspicion of otosclerosis in the request forms (Pearson’s chi-squared test, p < 0.005). Conclusion: The diagnosis of otosclerosis is frequently missed by radiologists on HRCT scans of the temporal bone in a clinical setting. Possible reasons include a relative lack of experience of general radiologists with temporal bone imaging as well as the failure of clinicians to unambiguously communicate their suspicion of otosclerosis.

Cochlear Implantation in Far Advanced Otosclerosis: A Systematic Review and Meta-Analysis

OBJECTIVE

To evaluate speech outcomes and facial nerve stimulation (FNS) rates in patients with far advanced otosclerosis (FAO) after cochlear implantation.

METHODS

A systematic review was performed using standardized methodology of Medline, EMBASE, PubMed, Cochrane, and Web of Science databases. Studies were included if adults with FAO underwent cochlear implantation. Exclusion criteria included concurrent otologic history (e.g., Meniere's disease, superior canal dehiscence), non-English-speaking implant users, case reports, abstracts, and letters/commentaries. Bias was assessed using the Newcastle-Ottawa Scale for cohort studies and the National Institute of Health Scale for case series. The primary outcome measure was speech discrimination and the secondary outcomes were rates of partial insertion and FNS.

RESULTS

Twenty-seven studies evaluated cochlear implantation in FAO. Due to the heterogeneity of testing methods, statistical pooling of speech discrimination was not feasible, but qualitative synthesis indicated a positive effect of implantation. Pooled rates of FNS were 18% (95% confidence interval, CI 12%-27%) and the rate of partial insertion was 10% (95% CI 7%-15%).

CONCLUSION

Cochlear implantation in FAO demonstrates significant gains in speech discrimination scores with higher rates of FNS and partial insertion. Laryngoscope, 2022.