Diagnostic Efficacy of High-Resolution Computed Tomography Densitometry for Diagnosing Otosclerosis

OBJECTIVES

The purpose of this study is to evaluate the reliability of temporal bone density measurements for diagnosing otosclerosis.

MATERIALS AND METHODS

A retrospective case-control study is presented. Bone density was measured in Hounsfield units (HUs) by using high-resolution computed tomography in eight regions of interest (ROI) where otosclerotic foci are usually localized. The density of 113 otosclerotic ears was compared with that of 33 nonotosclerotic ears to determine sensitivity and specificity. Furthermore, the binormal receiver operating characteristic curve of each ROI's density was calculated to estimate the diagnostic value for osteosclerosis. In addition, the radiological density of seven cases-where radiological visual examination exhibited no findings but surgery confirmed stapes fixation-was compared with nonotosclerotic controls.

RESULTS

ROI densities were significantly lower in otosclerotic patients compared with nonotosclerotic controls. The area under the curve of the fissula ante fenestram (FAF) presented the highest diagnostic performance: 1,871 HU cut-off value (area under the curve = 0.986), 96.64% sensitivity, and 100% specificity. Significantly lower densities in the FAF area were observed in the seven cases with negative radiology but intraoperatively confirmed otosclerosis.

CONCLUSION

The high-resolution computed tomography density of the FAF is a reliable measurement for diagnosing otosclerosis. A value less than 1,871 HU exhibited the highest sensitivity and specificity in a European Caucasian population.

Diagnostic utility of labyrinth capsule bone density in the diagnosis of otosclerosis with high resolution tomography

OBJECTIVE

The aim of this study is to compare the bone density around the otic capsule in otosclerotic patients with a control group, and find the cut-off values of bone density from which we can diagnose the disease.

MATERIAL AND METHODS

A retrospective case-control study was performed. Bone densities in Hounsfield units (HU) from 28 otosclerotic ears were compared to the densities of 33 non otosclerotic capsules. These densities were measured in eight regions of interest (ROI) where the otosclerotic foci are usually found. The mean density of these regions (PROMED) was taken. Furthermore, the ROC curves of each ROI and the mean density (PROMED) were calculated.

RESULTS

All radiological densities in HU of each ROI and the mean density in otosclerotic patients were lower compared to non otosclerotic ears. The area under the ROC curve of each ROI and the mean density showed that the areas with greater accuracy for the diagnosis of otosclerosis were mean density, the fissula ante fenestram, and precochlear region, with cut-off values of 1980HU, 1750HU and 2114HU, respectively.

CONCLUSION

The mean density of the otic capsule (PROMED), the density in the fissula ante fenestram (ROI1) and in the precochlear region (ROI3) seem to be the most useful parameters to make a diagnosis of otosclerosis.

[Foreign bodies in maxillary sinus]

INTRODUCTION

Foreign bodies in maxillary sinus (FBMS), whatever their origin or nature, are an unusual clinical condition. Diagnosis is based on the radiological findings in a clinical context of unilateral chronic rhinosinusitis. Treatment is the surgical removal of the intrasinusal foreign body.

PATIENTS AND METHODS

To identify FBMS, the records of 68 patients with unilateral chronic rhinosinusitis operated on from 2000 to 2007 were reviewed.

RESULTS

From 68 records reviewed, we found 11 (16 %) FBMS. Ten (91 %) of these 11 foreign bodies were thought to come from the teeth and the last 1 (9 %) had a non odontogenic origin. Eight of the 11 (73 %) patients with FBMS presented with chronic maxillary sinusitis symptoms and all patients showed radiological findings. Treatment was the surgical removal of the foreign body, in 9 (82 %) patients through endonasal approach by functional endoscopic sinus surgery (FEES) and in the other 2 (18 %) patients a mixed surgical procedure by endonasal meatotomy and oral antrotomy was required.

CONCLUSIONS

Chronic maxillary sinusitis showing FBMS is rare and it must be suspected with a prior history of dental procedures. The most frequent source of FBMS is material of odontogenic origin, and non-odontogenic origin secondary to an external injury in an accident or assault is much more unusual. We also review the nature of these foreign bodies, their clinical implications and treatment options.