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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
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,
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.
Otol Neurotol
37:
9–15, 2016.
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
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.
METHODS
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
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.nlThe authors disclose no conflicts of interest.
Otology & Neurotology
37
:9–15 2015, Otology & Neurotology, Inc.
Reprinted by permission of Otol Neurotol. 2016; 37(1):9-15.
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