Are computed tomography and densitometric measurements useful in otosclerosis with mixed hearing loss? A retrospective clinical study

Abstract

The objective of the study was to investigate the relationship between extent of otosclerotic foci and audiological findings in otosclerotic patients with mixed hearing loss using high-resolution computed tomography (HRCT) and also to measure the density of bony labyrinth in otosclerotic patients and compared with control group. This was a retrospective study. Twenty-five patients with clinical otosclerosis and mixed hearing loss were included in the study. The average threshold of air-bone conductions (AC, BC) within the 0.5-4 kHz frequency range, and average air bone gap (ABG) were calculated. Eleven patients with normal HRCT who received cochlear implant were included in the study as the control group. The lesions in HRCT were staged according to their extension. Eight different points of the otic capsule in each patient were measured using HRCT. Fifty ears total, from 25 patients, had bilateral otosclerosis. The mean AC of all the ears was 63 dB, mean BC was 35.2 dB, and mean ABG was 27.8 dB. HRCT staging indicated 22 ears had Grade 1, 21 ears had Grade 2, and 7 ears had Grade 3 lesions. There was a statistically significant difference between the mean AC, BC of ears with Grade 1 and Grade 2 when compared with the mean AC, BC of ears with Grade 3. When comparing the densitometric measurements of fissula ante fenestram localizations, a statistically significant difference was observed. HRCT examination and densitometric measurements in otosclerotic patients with mixed hearing loss presented significant results. We were unable to show a significant relationship between early stage and hearing thresholds, but there was a significant relationship in advanced stage. Densitometric measurements may provide significant results for otosclerosis, particularly for the FAF region when comparing with control group.

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

“…Prior studies have examined densitometry measurements on HRCT and found significantly lower density in active otospongiosis compared with control ears. [24][25][26] Moreover, hypodensity at the fissula ante fenestram has been shown to correlate with a conductive-component of hearing loss in the low frequencies. [24][25][26] Tringali and colleagues also found density measurements at the fissula ante fenestram were significantly lower in patients with otosclerosis compared with the control group.…”

Bone mineral density measurements in otosclerosis using dual‐energy X‐ray absorptiometry

“…There are many studies in the literature concerning densitometric measurements of the labyrinth together with the temporal bone in otosclerosis using high‐resolution computed tomography (HRCT), which provides a quantitative evaluation of the cochlear capsule density . Densitometry using HRCT has also been reported to provide information about the otospongiotic or sclerotic stage of the otosclerotic foci and has been shown to be an effective method of diagnosis of otosclerosis .…”

Correlation between the Size, CT Density of Otosclerotic Foci, and Audiological Tests in Cases of Otosclerosis

“…AC and BC thresholds were worse in cases of extensive otosclerotic foci, as declared by Marx et al [18] . Kultar et al [19] concluded that there was no significant relationship between early stage (fenestral, focal) and hearing thresholds, but there was a significant relationship in advanced (diffuse) stage. In our study, we were unable to find any significant relationship between the size of otosclerotic lesions in any of the CT grades and hearing thresholds (BC and ABG).…”

“…We chose to measure the CT density of otosclerotic lesions at the FAF region, as it is the most commonly affected area in otosclerosis [20] and because lower density in this region often appears in otosclerosis [19,21] .…”