internal auditory canal
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Author(s):  
Christine J. Colasacco ◽  
Katrina Stidham ◽  
Gillian Graifman ◽  
Jose F. Dominguez ◽  
Sabrina Zeller ◽  
...  

2022 ◽  
pp. 197140092110674
Author(s):  
Kamran Munawar ◽  
Eytan Raz ◽  
Seena Dehkharghani ◽  
Girish M Fatterpekar ◽  
Tobias K Block ◽  
...  

StarVIBE is a 3D gradient-echo sequence with a radial, stack-of-stars acquisition having spatial resolution and tissue contrast. With newer sequences, it is important to be familiar with sequence tissue contrasts and appearance of anatomical variants. We evaluated 450 patients utilizing this sequence; 35 patients demonstrated fluffy “cotton wool” enhancement at the internal auditory canal fundus without clear pathology. We favor this represents anatomic neurovascular enhancement that StarVIBE is sensitive to and is a touch-me-not finding.


2022 ◽  
Vol 12 ◽  
Author(s):  
Weixing Liu ◽  
Gui Chen ◽  
Junyang Xie ◽  
Tianhao Liang ◽  
Chunyi Zhang ◽  
...  

Objectives: To develop and evaluate a new coordinate system for MRI of the vestibular system.Methods: In this study, 53 internal auditory canal MRI and 78 temporal bone CT datasets were analyzed. Mimics Medical software version 21.0 was used to visualize and three-dimensionally reconstruct the image data. We established a new coordinate system, named W–X, based on the center of the bilateral eyeballs and vertex of the bilateral superior semicircular canals. Using the W–X coordinate system and Reid's coordinate system, we measured the orientations of the planes of the anterior semicircular canal (ASCC), the lateral semicircular canal (LSCC), and the posterior semicircular canal (PSCC).Results: No significant differences between the angles measured using CT and MRI were found for any of the semicircular canal planes (p > 0.05). No statistical differences were found between the angles measured using Reid's coordinate system (CT) and the W–X coordinate system (MRI). The mean values of ∠ASCC & LSCC, ∠ASCC & PSCC, and ∠LSCC & PSCC were 84.67 ± 5.76, 94.21 ± 3.81, and 91.79 ± 5.22 degrees, respectively. The angle between the LSCC plane and the horizontal imaging plane was 15.64 ± 3.92 degrees, and the angle between the PSCC plane and the sagittal imaging plane was 48.79 ± 4.46 degrees.Conclusion: A new W–X coordinate system was developed for MRI studies of the vestibular system and can be used to measure the orientations of the semicircular canals.


Diagnostics ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 120
Author(s):  
Takahiro Kanaya ◽  
Yasuo Murai ◽  
Kanako Yui ◽  
Shun Sato ◽  
Akio Morita

Lipomas of the cerebellopontine angle (CPA) and internal auditory canal (IAC) are relatively rare tumors. Acoustic neurinoma is the most common tumor in this location, which often causes hearing loss, vertigo, and tinnitus. Occasionally, this tumor compresses the brainstem, prompting surgical resection. Lipomas in this area may cause symptoms similar to neurinoma. However, they are not considered for surgical treatment because their removal may result in several additional deficits. Conservative therapy and repeated magnetic resonance imaging examinations for CPA/IAC lipomas are standard measures for preserving cranial nerve function. Herein, we report a case of acoustic neurinoma and CPA lipoma occurring in close proximity to each other ipsilaterally. The main symptom was hearing loss without facial nerve paralysis. Therefore, facial nerve injury had to be avoided. Considering the anatomical relationships among the tumors, cranial nerves, and CPA/IAC lipoma, we performed total surgical removal of the acoustic neurinoma. We intentionally left the lipoma untreated, which enabled facial nerve preservation. This report may be a useful reference for the differential diagnosis of similar cases in the future.


2021 ◽  
Vol 2021 ◽  
pp. 1-4
Author(s):  
Myriam Jrad ◽  
Haifa Zlitni ◽  
Miriam Boumediene ◽  
Atef Ben Nasr ◽  
Meriem Bouzrara

Inner ear hemorrhage is an extremely rare cause of sudden sensorineural hearing loss with few cases reported in the literature. We report the case of a 30-year-old male who presented with a sudden left ear hearing loss, with no tinnitus nor vertigo. The audiogram revealed a profound left sensorineural hearing loss. An MRI of the brain and internal auditory canal was performed 3 weeks after and revealed an increased signal intensity on T1-weighted (T1W) and T2 fluid-attenuated inversion recovery (FLAIR) images in the left cochlea. No other abnormalities were found, in particular no enhancement after intravenous administration of gadolinium. The CISS 3D sequence showed a signal of discreetly lower intensity in the left cochlea compared to the right one. The diagnosis of intracochlear hemorrhage was made. No improvement of the hearing loss has been noted after medical treatment and hyperbaric oxygen therapy.


2021 ◽  
Vol 2 (20) ◽  
Author(s):  
Melanie Lang-Orsini ◽  
Julian Wu ◽  
Carl B. Heilman ◽  
Alina Kravtsova ◽  
Gene Weinstein ◽  
...  

BACKGROUND Primary meningeal melanocytic neoplasms are exceedingly rare tumors, representing only 0.06% to 0.1% of all primary brain tumors and ranging in spectrum from benign localized tumors to highly aggressive malignant lesions. The diagnosis of these tumors is often challenging from clinical, radiological, and pathologic standpoints. Equally challenging is the distinction between primary meningeal melanocytic neoplasm and metastatic melanoma. OBSERVATIONS The authors reported the case of a 41-year-old man with imaging findings diagnostic of neurofibromatosis type 2: bilateral internal auditory canal lesions (most consistent with bilateral vestibular schwannomas), two dura-based lesions presumed to be meningiomas, multiple spinal lesions consistent with peripheral nerve sheath tumors, and one intramedullary spinal lesion consistent with an ependymoma. Biopsy of these lesions revealed melanocytic neoplasms with mild to moderate atypia and a mildly elevated proliferation index, which made the distinction between benign and malignant challenging. In addition, the disseminated nature of these tumors made it difficult to determinate whether they arose from the meninges or represented metastases from an occult primary melanoma. LESSONS This case illustrated the challenges presented by the diagnosis of meningeal melanocytic neoplasms and highlighted the importance of integrating the clinical and radiographic findings with histologic appearance and molecular studies.


2021 ◽  
Vol 2 (18) ◽  
Author(s):  
Masato Ito ◽  
Yoshinori Higuchi ◽  
Kentaro Horiguchi ◽  
Shigeki Nakano ◽  
Shinichi Origuchi ◽  
...  

BACKGROUND Anatomical variations, such as high jugular bulbs and air cell development in the petrosal bone, should be evaluated before surgery. Most bone defects in the internal auditory canal (IAC) posterior wall are observed in the perilabyrinthine cells. An aberrant vascular structure passing through the petrous bone is rare. OBSERVATIONS A 48-year-old man presented with a right ear hearing disturbance. Magnetic resonance imaging revealed a 23-mm contrast-enhancing mass in the right cerebellopontine angle extending into the IAC, consistent with a right vestibular schwannoma. Preoperative bone window computed tomographic scans showed bone defects in the IAC posterior wall, which ran farther posteroinferiorly in the petrous bone, reaching the medial part of the jugular bulb. The tumor was accessed via a lateral suboccipital approach. There was no other major vein in the cerebellomedullary cistern, except for the vein running from the brain stem to the IAC posterior wall. To avoid complications due to venous congestion, the authors did not drill out the IAC posterior wall or remove the tumor in the IAC. LESSONS Several aberrant veins in the petrous bone are primitive head sinus remnants. Although rare, their surgical implication is critical in patients with vestibular schwannomas.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anandhan Dhanasingh ◽  
Daniel Erpenbeck ◽  
Masoud Zoka Assadi ◽  
Úna Doyle ◽  
Peter Roland ◽  
...  

AbstractIdentification of the inner ear malformation types from radiographs is a complex process. We hypothesize that each inner ear anatomical type has a uniqueness in its appearance in radiographs. The outer contour of the inner ear was captured from the mid-modiolar section, perpendicular to the oblique-coronal plane, from which the A-value was determined from CT scans with different inner ear anatomical types. The mean A-value of normal anatomy (NA) and enlarged vestibular aqueduct syndrome (EVAS) anatomical types was greater than for Incomplete Partition (IP) type I, II, III and cochlear hypoplasia. The outer contour of the cochlear portion within the mid-modiolar section of NA and EVAS resembles the side view of Aladdin’s lamp; IP type I resembles the side-view of the Sphinx pyramid and type II a Pomeranian dog’s face. The steep spiraling cochlear turns of IP type III resemble an Auger screw tip. Drawing a line parallel to the posterior margin of internal auditory canal (IAC) in axial-view, bisecting the cavity into cochlear and vestibular portions, identifies common-cavity; whereas a cavity that falls under the straight-line leaving no cochlear portion identifies cochlear aplasia. An atlas of the outer contour of seventy-eight inner ears was created for the identification of the inner malformation types precisely.


2021 ◽  
Vol 5 (2) ◽  
pp. V3
Author(s):  
Gang Song ◽  
Liyong Sun ◽  
Yuhai Bao ◽  
Jiantao Liang

The main objectives of microsurgery for vestibular schwannoma are total tumor removal and preservation of facial and cochlear nerve function. For giant tumors, total tumor removal and facial nerve function preservation are challenging. The semisitting position has some advantages. In this video the authors show the removal of a giant vestibular schwannoma with the patient in a semisitting position. They demonstrate the advantages of the semisitting technique, such as the two-handed microsurgical dissection technique and a clear operative field. Finally, a small residual tumor in the internal auditory canal was removed by endoscopy. The patient’s facial function was House-Brackmann grade I at discharge. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID2176


2021 ◽  
Vol 5 (2) ◽  
pp. V5
Author(s):  
Felipe Constanzo ◽  
Bernardo Correa de Almeida Teixeira ◽  
Mauricio Coelho Neto ◽  
Ricardo Ramina

Inadvertent laceration of the jugular bulb is a potentially serious complication of the retrosigmoid transmeatal approach to vestibular schwannomas. Here, the authors present the case of a 51-year-old woman with a right Hannover T4a vestibular schwannoma and bilateral high-riding jugular bulb, which was opened during drilling of the internal auditory canal (IAC). They highlight the immediate management of this complication, technical nuances for closing the defect without occluding the jugular bulb, and modifications of the standard technique needed to continue surgical resection. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID2155


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