scholarly journals Prevalence of radiographic semicircular canal dehiscence in very young children: an evaluation using high-resolution computed tomography of the temporal bones

2012 ◽  
Vol 42 (12) ◽  
pp. 1456-1464 ◽  
Author(s):  
Mari Hagiwara ◽  
Jamil A. Shaikh ◽  
Yixin Fang ◽  
Girish Fatterpekar ◽  
Pamela C. Roehm
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Young Children ◽  
Semicircular Canal ◽  
High Resolution Computed Tomography ◽  
Very Young Children ◽  
Temporal Bones ◽  
Canal Dehiscence

Anatomy of the Transarcuate Approach to the Petrous Apex

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P98-P98
Author(s):  
Alice D Lee ◽  
Sanaz Hamidi ◽  
Hamid R Djalilian
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Semicircular Canal ◽  
Petrous Apex ◽  
Minimal Risk ◽  
High Resolution Computed Tomography ◽  
Superior Semicircular Canal ◽  
The Mean ◽  
Temporal Bones ◽  
Anterior Posterior

Problem The petrous apex is considered to be one of the most difficult areas of the temporal bone to approach surgically. We present data describing the dimensions of a transarcuate approach to the petrous apex, as measured on high resolution computed tomography. Methods Measurements of the mean dimensions and ranges through the crura of the superior semicircular canal were made. The measurements were obtained from high-resolution computed tomography images of 30 temporal bones in 19 consecutively presenting patients with a pneumatized posterior petrous apex cell tract on CT. Measurements were obtained with the use of the standard PACS (picture archiving and communication system) software. Results The mean anterior-posterior space in the superior semicircular canals without transcrural pneumatization was 4.96±0.39 mm. The mean superior- inferior dimension was 4.98±0.48 mm. The same measurements in canals with pneumatized intercrural tracts were 5.17±0.51 mm and 5.11±0.62 mm respectively. The mean anterior-posterior distance and superior-inferior distance of the intercrural air tracts themselves were 2.09±0.57 and 2.01±0.45mm. There was a statistically significant difference in the anterior-posterior size between the pneumatized and non-pneumatized canals but not in the superior-inferior distance. Conclusion Pneumatized bones demonstrate a slight increase in the subarcuate dimensions as compared to non-pneumatized bones. The transarcuate approach is a viable one for drainage and biopsy of the petrous apex. Significance Our study demonstrates that the transarcuate approach is anatomically possible for drainage of the petrous apex with minimal risk to the superior semicircular canal. This would be especially useful for the drainage of cholesterol granulomas of the petrous apex or biopsy in this area.

Dehiscence of Bone Overlying the Superior Semicircular Canal as a Cause of an Air-Bone Gap on Audiometry

2003 ◽  
Vol 12 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Kenneth M. Cox ◽  
Daniel J. Lee ◽  
John P. Carey ◽  
Lloyd B. Minor
Keyword(s):  
Hearing Loss ◽  
High Resolution ◽  
Middle Ear ◽  
Semicircular Canal ◽  
Conductive Hearing Loss ◽  
Superior Canal Dehiscence ◽  
High Resolution Ct ◽  
Temporal Bones ◽  
Conductive Hearing ◽  
Canal Dehiscence

Dehiscence of bone overlying the superior semicircular canal can result in a syndrome of vertigo and oscillopsia induced by loud noises or by maneuvers that change middle ear or intracranial pressure. Patients with this disorder can also experience a heightened sensitivity to bone-conducted sounds in the presence of normal middle ear function. High-resolution CT scans of the temporal bones demonstrate the dehiscence. The authors describe a patient with bilateral superior canal dehiscence who had bilateral low-frequency conductive hearing loss, normal middle ear function, intact acoustic reflexes, and intact vestibular-evoked myogenic potentials. These findings would not be expected on the basis of a middle ear cause of the conductive hearing loss. A high-resolution CT scan of the temporal bones in this patient revealed bilateral superior canal dehiscence. Normal acoustic immittance findings in the presence of conductive hearing loss should alert clinicians to the possibility of inner ear cause of an air-bone gap due to superior canal dehiscence

scholarly journals Superior Canal Dehiscence: A Comparative Postmortem Multislice Computed Tomography Study

OTO Open ◽  
2018 ◽  
Vol 2 (3) ◽  
pp. 2473974X1879357 ◽  
Author(s):  
Philipp Mittmann ◽  
Arne Ernst ◽  
Rainer Seidl ◽  
Anna-Felicitas Skulj ◽  
Sven Mutze ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Ct Scan ◽  
Temporal Bone ◽  
Multislice Ct ◽  
Ct Imaging ◽  
Autopsy Findings ◽  
Superior Canal Dehiscence ◽  
Temporal Bones ◽  
Canal Dehiscence

Objective Superior canal dehiscence is defined by missing bony coverage of the superior canal against the middle cranial fossa. The gold standard in diagnosis is high-resolution computed tomography (CT). A false-positive CT scan, identifying a dehiscence when one is not present, could lead to unnecessary surgical therapy. This study aims to compare postmortem CT scans with autopsy findings with regard to superior canal dehiscence. Study Design Postmortem study. Setting Tertiary referral center. Subjects and Methods Twenty-two nontraumatic death cases within a 3-month period (January to March 2017) were included with 44 temporal bones. Each body underwent postmortem head CT prior to medicolegal autopsy. The middle fossa floor was exposed, and if present, the superior semicircular canal dehiscence was identified and measured. In each case, 3 comparable photographs were taken during the autopsy (left temporal bone, right temporal bone, overview). Results Autopsy findings revealed bony dehiscences in 11% of the temporal bones, whereas CT scan revealed bony dehiscences in 16%. The length of the dehiscences were longer when measured by CT imaging. Conclusion The diagnosis of superior canal dehiscence syndrome requires high-resolution CT with clinical symptoms and physiologic evidence of a third mobile window. Our study underlines a mismatch between multislice CT imaging in the coronal plane and the presence of a dehiscence on autopsy.

scholarly journals Head rotation evoked tinnitus due to superior semicircular canal dehiscence

2009 ◽  
Vol 124 (3) ◽  
pp. 333-335 ◽  
Author(s):  
E-C Nam ◽  
R Lewis ◽  
H H Nakajima ◽  
S N Merchant ◽  
R A Levine
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Semicircular Canal ◽  
Head Rotation ◽  
Bony Defect ◽  
Case Presentation ◽  
Superior Semicircular Canal Dehiscence ◽  
Superior Semicircular Canal ◽  
The Right ◽  
Canal Dehiscence

AbstractIntroduction:Superior semicircular canal dehiscence affects the auditory and vestibular systems due to a partial defect in the canal's bony wall. In most cases, sound- and pressure-induced vertigo are present, and are sometimes accompanied by pulse-synchronous tinnitus.Case presentation:We describe a 50-year-old man with superior semicircular canal dehiscence whose only complaints were head rotation induced tinnitus and autophony. Head rotation in the plane of the right semicircular canal with an angular velocity exceeding 600°/second repeatedly induced a ‘cricket’ sound in the patient's right ear. High resolution temporal bone computed tomography changes, and an elevated umbo velocity, supported the diagnosis of superior semicircular canal dehiscence.Conclusion:In addition to pulse-synchronous or continuous tinnitus, head rotation induced tinnitus can be the only presenting symptom of superior semicircular canal dehiscence without vestibular complaints. We suggest that, in our patient, the bony defect of the superior semicircular canal (‘third window’) might have enhanced the flow of inner ear fluid, possibly producing tinnitus.

Evaluation of the mastoid air cell system by high resolution computed tomography: three-dimensional multiplanar volume rendering technique

2003 ◽  
Vol 117 (8) ◽  
pp. 595-598 ◽  
Author(s):  
Ahmet Koç ◽  
Gazanfer Ekinci ◽  
A. Mert Bilgili ◽  
Ihsan N. Akpinar ◽  
Hamdi Yakut ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Temporal Bone ◽  
Volume Rendering ◽  
Three Dimensional ◽  
Cell System ◽  
Mastoid Cavity ◽  
High Resolution Computed Tomography ◽  
Mastoid Pneumatization ◽  
Temporal Bones

The mastoid air cell system is an important contributor to the pathophysiology of middle-ear inflammatory disease. The mastoid cavity is not only an air reservoir, but also an active space for gas exchange. Various methods of temporal bone imaging have been designed to investigate mastoid pneumatization. In this study, we examined 100 normal temporal bones for the evaluation of mastoid pneumatization. Mastoid air cell systems were measured by reconstructed axial and coronal high resolution computed tomography (HRCT) images. The reconstructions were made by a three-dimensional multiplanar volume rendering (3D MPVR) technique. The mean volume of the mastoid air cell pneumatization was 7.9 cm3 (4.0-14.0 cm3, SD = 2.3 cm3). The ears were allocated to the groups with respect to measured mastoid air cell pneumatization. Twenty-eight per cent of the ears have small pneumatization with an aircell system not exceeding 6 cm3. Fifty-two per cent had an air cell system between six and 10 cm3, and 20 per cent had an air cell system exceeding 10 cm3. With its excellent imaging quality and the ability to eliminate bone and soft tissue, HRCT is the best method for evaluating the mastoid air cell system. The 3D MPVR technique must be used tomeasure the temporal bone/mastoid pneumatization for the best results.

Computed Tomography in the Diagnosis of Cochlear Otosclerosis

1986 ◽  
Vol 94 (4) ◽  
pp. 434-438 ◽  
Author(s):  
Brian W. Blakley ◽  
Peter A. Hilger ◽  
Saul Taylor ◽  
Jerome Hilger
Keyword(s):  
Computed Tomography ◽  
Hearing Loss ◽  
High Resolution ◽  
Sensorineural Hearing Loss ◽  
Sensorineural Hearing ◽  
High Resolution Computed Tomography ◽  
Temporal Bones

Twelve patients with surgically proven otosclerosis and sensorineural hearing loss were studied with high-resolution computed tomography (CT). The purpose was to Identify abnormal bony changes that could be diagnostic of cochlear otosclerosis. Of the 24 temporal bones thus studied, 10 showed positive findings. The findings in our study—as well as those of others—show a pericochlear zone of radiolucency. The precise origin of this is undetermined.

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