Diagnostic performance of high resolution computed tomography in otosclerosis

Abstract

AIMTo determine the sensitivity and specificity of high resolution computed tomography (HRCT) in the diagnosis of otosclerosis.METHODSA systematic literature review was undertaken to include Level I-III studies (Oxford Centre for Evidenced based Medicine) that utilised HRCT to detect histology confirmed otosclerosis. Quantitative synthesis was then performed.RESULTSBased on available level III literature, HRCT has a relatively low sensitivity of 58% (95%CI: 49.4-66.9), a high specificity, 95% (95%CI: 89.9-98.0) and a positive predictive value of 92% (95%CI: 84.1-95.8). HRCT is better at diagnosing the more prevalent fenestral form of otosclerosis but remains vulnerable to inframillimetre, retrofenestral and dense sclerotic lesions, despite the advent of more advanced CT scanners with improved collimation.CONCLUSIONWhilst the diagnosis of otosclerosis remains largely clinical, HRCT remains the gold standard imaging of choice for the middle ear and serves as a useful adjunct to the clinician, helping to delineate extent of disease and exclude other causes.

Retrospective Review of Otic Capsule Contour and Thickness in Patients with Otosclerosis and Individuals with Normal Hearing on CT

“…A recent systematic review suggests that high-resolution CT has a low sensitivity of 58%, high specificity of 95%, and a high PPV of 92%, but is limited in sub-millimeter disease, retrofenestral disease and dense sclerotic lesions. 24 Our study improves the sensitivity and specificity for diagnosis of otosclerosis by using a standardized plane and clearly defined landmarks for quantitative assessment of the otic capsule regardless of phase of disease.…”

Bilateral Cochlear Otosclerosis; Clinic and Radiologic Findings

“…Otosclerosis is the focal osseous dyscrasia specific to the endochondral bone of the otic capsule that consists of circumscribed foci of new, softer and more vascular bone, instead of the avascular bone of the adults (1,2). It is believed that the cartilaginous remnants trapped within the endochondral bone of the otic capsule are remodeled and replaced by highly vascular, immature bone.…”

“…Recent studies report that HRCT has >90% sensitivity in otosclerosis diagnosis. It shows the demineralized lesions in the otic capsule (stapes footplate, cochlea, and labyrinth) and the lesions that appears as a lucent or hypodense focus (1,3,4,11,15). A thickened footplate, narrowed oval window or round window niche are the HRCT findings in the fenestral type of otosclerosis (15).…”

“…Osteogenesis imperfecta, Paget's disease, ankylosing spondylitis, rheumatoid arthritis, and syphilis are the other rare diseases that demineralize the cochlear capsule, and they can mimic the appearance of cochlear otosclerosis in HRCT (3,11,15). HRCT may also play a significant role in distinguishing otosclerosis from other pathological conditions like tympanosclerosis, cholesteatoma, ossicular fixation, and congenital malformations that cause conductive hearing loss (1,3,4). In our case, low-density areas that caused the double-ring sign were observed in both pericochlear areas ( Figure 3A-B).…”

Evaluation of balance function in patients with radiologically (CT scan) confirmed otosclerosis

“…In the last few years, the study of otosclerosis has principally been devoted to the histochemistry of otosclerotic foci 4,5 . It is important to distinguish between clinical, nonclinical or histological otosclerosis; the latter is about 10 times more common than the former 6 . A study has revealed histological otosclerosis on temporal bones in 12% of patients 7 .…”