HSC Section 8_April 2017

CT IMAGING IN OTOSCLEROSIS

FIG. 1.

Flowchart.

otosclerosis intraoperatively were not mentioned. A sub- stantial amount of outcome data, 37%, 38%, and 52% respectively, were missing in three studies (22,26,27). A complete case analysis was performed in all of these studies. Seven studies characterized by a moderate-to- high relevance and moderate-to-low risk of bias were included for data extraction (2,3,6,16–20). Data Extraction The study characteristics are presented in Table 3. There are major dissimilarities between studies regarding the study population, index test, and reference test. As mentioned previously, only two studies included patients with a clinical suspicion of otosclerosis based on the presence of conductive hearing loss, a normal tympanic membrane, and absent stapedial reflexes (16–18). In the other studies patients with an indication for middle ear surgery or patients with confirmed otosclerosis were included (2,3,6,19,20). High-resolution, cone beam, mul- tislice, and helical CTs were evaluated in the included studies. In five studies (6,16–20) middle ear surgery was used as the reference test whereas in two studies (2,3) histopathology was used. We decided to refrain from pooling the data because of these dissimilarities. Prev- alences, sensitivities, specificities, and post-test proba- bilities are presented in Table 4.

bias was low in two studies (2,3), moderate in five studies (6,16–20), and high in the remaining six studies (21–27). In the majority of the included studies, it was not clear whether a consecutive series of patients was included (6,18,20–27). In two studies only those patients with available histopathologic results were included (2,3). Standardization of the index test (CT) was either not achieved or not adequately described in six studies (16,17,21,23–27). Slice thickness varied between 0.6 and 1mm in the study performed by Marx et al./Lagleyre et al. (16,17) and between 1 and 2mm in the study performed by de Oliveira Vicente (24,25). Two different types of scanners were used in the study by Mori et al. (23). In the study performed by Berretini et al. (26) some CT scans were assessed on a computer-dedicated work- station, whereas others were manually read from a printed version of the CT scan. The diagnostic criteria and number of assessors were not mentioned in the study performed by Bozorg Grayeli et al. (21). CT settings were not mentioned in the study performed by Shin et al. (27). Standardization of the reference test (middle ear surgery) was either not achieved or not adequately described in nine studies (6,19–27). In two studies (6,23), middle ear surgery was not performed in all of the included patients, but all patients were included in the analyses nonetheless. In nine studies (6,19–27), the criteria used for diagnosing

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