Imaging of the temporal bone.
Classical descriptions of the temporal bone are based on its five embryologically distinct osseous components: the petrous, tympanic, mastoid, squamous, and styloid portions.
Journal Article↗
Biomedical subjects
H Christian Davidson
Publications and source records attributed to H Christian Davidson.
Intralabyrinthine schwannomas: diagnosis, management, and a new classification system.
OBJECTIVE: To outline the diagnosis and management of intralabyrinthine schwannomas and to propose a new classification system to further define them. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center at a university hospital. PATIENTS: Twenty-eight patients seen at the institution with intralabyrinthine schwannomas between 1996 and 2002 were included in the study. INTERVENTIONS: Diagnosis was made with magnetic resonance imaging in all but one case. Our ability to detect these tumors has been greatly enhanced by the introduction of high-resolution T2-weighted magnetic resonance imaging. Treatment options were observation with serial magnetic resonance imaging versus complete surgical removal via a translabyrinthine or transotic approach. Surgery was indicated for dizziness caused by the tumor or extralabyrinthine growth. MAIN OUTCOME MEASURES: Clinical features, audiology, radiology, and management outcomes were evaluated. RESULTS: Eight patients have undergone successful surgery with removal of their tumors and resolution of symptoms. One patient chose to have stereotactic radiotherapy. Of the 20 patients who were managed with observation and serial magnetic resonance imaging, only 1 has shown significant growth requiring surgical removal. CONCLUSION: Intralabyrinthine schwannomas are uncommon tumors that mimic the clinical features of many other neurotologic conditions. A high index of suspicion and precise imaging are often required to detect these tumors. Surgical treatment is indicated for specific indications and will be needed in the minority of patients with this disorder. The classification system that we propose is helpful in both the diagnosis and the management of these tumors.
Adult↗
Radiology teaching presentation tools.
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Audiovisual Aids↗
Imaging of the temporal bone.
Classical descriptions of the temporal bone are based on its five embryologically distinct osseous components: the petrous, tympanic, mastoid, squamous, and styloid portions.
Bone Diseases↗
The silent sinus syndrome: clinical and radiographic findings.
OBJECTIVE. The purpose of this article is to acquaint the reader with the clinical and imaging features of the silent sinus syndrome, which is relatively unknown. Discussion of the presentation, treatment, and theory regarding pathogenesis of the syndrome follows. CONCLUSION. The silent sinus syndrome consists of painless facial asymmetry and enophthalmos caused by chronic maxillary sinus atelectasis. Although the diagnosis is usually suspected clinically, it is confirmed radiologically by characteristic imaging features that include maxillary sinus outlet obstruction, sinus opacification, and sinus volume loss caused by inward retraction of the sinus walls.
Adult↗
Imaging findings of cochlear nerve deficiency.
BACKGROUND AND PURPOSE: High-resolution T2-weighted fast spin-echo MR imaging provides excellent depiction of the cisternal and intracanalicular segments of the vestibulocochlear and facial nerves. Absence or reduction in caliber of the cochlear nerve (deficiency) has been described in association with congenital sensorineural hearing loss (SNHL). Depiction of cochlear nerve integrity may be important for diagnosis and management of SNHL. METHODS: We retrospectively reviewed high-resolution T2-weighted fast spin-echo MR images of 22 patients examined for SNHL who had deficiency of the cochlear nerve. Images were evaluated for the presence and comparative size of the component nerves (facial, cochlear, superior vestibular, and inferior vestibular nerves), relative size of the internal auditory canal (IAC), and any associated inner ear abnormalities. The clinical history, results of the clinical examination, and audiometric findings were reviewed for each patient. RESULTS: Deficiency of the cochlear nerve was observed in 12 patients with congenital SNHL and in 10 patients with acquired SNHL. Hypoplasia of the IAC was observed in association with congenital deficiency of the cochlear nerve in 11 of 12 patients. Deficiency of the cochlear nerve was observed in association with acoustic schwannoma in two cases and with acquired labyrinthine abnormalities in seven cases. Hypoplasia of the IAC was not observed in association with acquired SNHL. CONCLUSION: Deficiency of the cochlear nerve can be shown by high-resolution T2-weighted fast spin-echo MR imaging. Deficiency may be observed in association with congenital or acquired SNHL and may be important in the assessment of patients for cochlear implantation. Hypoplasia of the IAC is an indicator of congenital cochlear nerve deficiency.
Adult↗