HSC Section 8_April 2017

Reprinted by permission of Otol Neurotol. 2016; 37(1):9-15.

Otology & Neurotology 37 :9–15 2015, Otology & Neurotology, Inc.

A Systematic Review of the Diagnostic Value of CT Imaging in Diagnosing Otosclerosis y Inge Wegner, Anne M. A. van Waes, y Arnold J. Bittermann, Sophie H. Buitinck, Caroline F. Dekker, Sophie A. Kurk, Matea Rados, and y Wilko Grolman Department of Otorhinolaryngology–Head and Neck Surgery; and y Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands

both positive and negative post-test probabilities were (relatively) high: 99% and between 51% and 67% respect- ively. In one study with a low prevalence of disease (9%), both positive and negative post-test probabilities were low (23% and 3% respectively). Overall, reported sensitivities ranged between 60% and 95%. Conclusion: Preoperative CT has little to add in establish- ing otosclerosis and may not be necessary to confirm the diagnosis. We would recommend reserving CT for those patients with suspected additional abnormalities, for specific preoperative planning, or out of legal necessity. Key Words: Conductive hearing loss — CT imaging — Diagnostic — HRCT — Otosclerosis — Radiology — Systematic review. suggested CT findings might serve as prognostic factors regarding surgical success (4–6). Findings such as exten- sive otosclerotic foci, cochlear involvement, and round window obliteration are associated with a poor prognosis and may influence treatment choice (7). Detection of concomitant anomalies such as large vestibular aqueduct, dehiscent facial canal, and superior semicircular canal dehiscence on CT further impact (surgical) planning (2). The aim of this review was to determine the diagnostic value of CT in otosclerosis in adult patients with conductive hearing loss and a clinical suspicion of otosclerosis. Search and Selection A systematic literature search in PubMed, Embase, and the Cochrane Library was conducted with the assistance of a clinical librarian (date of search: September 10, 2014). Relevant synonyms for the search terms ‘‘computed tomography’’ and ‘‘otosclerosis’’ were used (see Table 1 for the full search strategy). Duplicates were removed. Title and abstract screen- ing was performed independently by two authors per article (I.W., A.v.W., S.H.B., C.F.D, S.A.K., and M.R.) according to predetermined inclusion and exclusion criteria (see Fig. 1 for Otol Neurotol 37: 9–15, 2016. METHODS

Objective: To evaluate the diagnostic value of computed tomography (CT) in detecting otosclerosis in patients with conductive hearing loss and a clinical suspicion of otosclero- sis. Data Sources: PubMed, Embase, and the Cochrane Library. Study Selection: A systematic search was conducted. Stu- dies reporting original study data were included. Data Extraction: Relevance and risk of bias of the selected articles were assessed. Studies with low relevance, high risk of bias, or both were excluded. Prevalences, sensitivities, specificities, and post-test probabilities were extracted from the included articles. Data Synthesis: Seven studies characterized by a moderate to high relevance and moderate to low risk of bias were included for data extraction. The prevalence of otosclerosis was high (up to 100%) in the majority of the included studies. In those studies with a high prevalence of disease, Otosclerosis is characterized by an abnormal bone metabolism in the otic capsule (1). It mostly affects the stapes footplate and results in progressive hearing loss. History taking, physical examination, tuning fork testing, stapedius reflex testing, and pure-tone audiome- try all contribute to the diagnosis of otosclerosis. A definitive and reliable diagnosis can only be made during middle-ear inspection. Middle-ear inspection allows for simultaneous restoration of hearing. Computed tomography (CT) is the imaging modality of choice when imaging is performed (2,3). CT may be used in the diagnostic evaluation of otosclerosis, in the assessment of disease extent including cochlear involve- ment, and in planning specific surgical treatment. Oto- sclerosis is characterized by lucent or hypodense foci within the otic capsule on CT. Other CT findings include a thickened footplate, narrowed oval or round window niche, and the double ring sign (4). Several authors have Address correspondence and reprint requests to Inge Wegner, M.D., Department of Otorhinolaryngology–Head and Neck Surgery, G05.129, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands; E-mail: ENT-research@umcutrecht.nl The authors disclose no conflicts of interest.

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