Surface-Coil Magnetic Resonance Imaging of the Internal Auditory Canal and the Inner Ear Preliminary Report

1995 ◽  
Vol 104 (10) ◽  
pp. 776-782 ◽  
Author(s):  
Iwao Honjo ◽  
Eri Naito ◽  
Yasushi Natto ◽  
Haruo Takahashi ◽  
Kazumasa Nishimura ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Inner Ear ◽  
Internal Auditory Canal ◽  
Surface Coil ◽  
Cochlear Nerve ◽  
Acquisition Time ◽  
Computer Assisted ◽  
Resonance Imaging ◽  
Eighth Nerve

Parasagittal surface-coil magnetic resonance imaging of the internal auditory canal and the inner ear was performed. We used T2-weighted fast spin-echo sequences to visualize the inner ear and the individual nerves in the internal auditory canal with high contrast in a short acquisition time. Computer-assisted quantitative measurement of the nerves was performed to estimate the cross-sectional areas and the diameters of the nerves. The average diameters of the facial nerve, the cochlear nerve, and the vestibular nerve of normal-hearing individuals were, respectively, 1.1 ± 0.2 mm (mean ± SD), 1.2 ± 0.2 mm, and 1.5 ± 0.2 mm. In the cerebellopontine angle, the average diameter of the eighth nerve was 1.8 ± 0.2 mm. Two patients with unilateral and bilateral hearing loss were also presented. In the patient with unilateral deafness, the cochlear nerve of the diseased side was not identified and the eighth cranial nerve diameter was smaller than that of the normal side. In the patient with bilateral deafness, fibrosis of the inner ear and atrophy of the eighth nerve were demonstrated in the ear with posttraumatic deafness. The present method may represent a new approach to the assessment of pathologic processes involving the inner ear and the nerves in the internal auditory canal.

scholarly journals Anatomical and Pathological Findings of Magnetic Resonance Imaging in Idiopathic Sudden Sensorineural Hearing Loss

2020 ◽  
Vol 24 (4) ◽  
pp. 198-203
Author(s):  
Min Bum Kim ◽  
Jihyun Lim ◽  
Il Joon Moon
Keyword(s):  
Magnetic Resonance Imaging ◽  
Hearing Loss ◽  
Magnetic Resonance ◽  
Sensorineural Hearing Loss ◽  
Inner Ear ◽  
Internal Auditory Canal ◽  
Sudden Sensorineural Hearing Loss ◽  
Cochlear Nerve ◽  
Sensorineural Hearing ◽  
Resonance Imaging

Background and Objectives: We sought to evaluate the diagnostic and prognostic value of measurable parameters of internal auditory canal (IAC) magnetic resonance imaging (MRI) in patients with idiopathic sudden sensorineural hearing loss (ISSNHL).Subjects and Methods: We retrospectively reviewed the patients with ISSNHL who underwent IAC MRI from January 2008 to March 2019. Measurable parameters of IAC MRI, such as the diameter of the IAC, bony cochlear nerve canal, and cross-sectional area of the cochlear nerve, were measured by a single examiner. These parameters were then compared between the affected and healthy sides. Inner-ear abnormalities such as intralabyrinthine hemorrhage or labyrinthitis were also evaluated. The relationship between the surveyed parameters and the diagnosis of ISSNHL was assessed.Results: A total of 208 patients with ISSNHL were included. The measured parameters of IAC MRI were not different between the affected and healthy sides and were also not associated with the diagnosis of ISSNHL. However, inner-ear abnormalities of IAC MRI in ISSNHL displayed a significant association with worse hearing before and after treatment. An age that was older than 40 years also correlated with poorer outcomes. Further, inner-ear abnormalities were more frequently detected when IAC MRI was performed early after ISSNHL onset.Conclusions: Patients with ISSNHL and inner ear abnormalities such as intralabyrinthine hemorrhage or labyrinthitis identified via IAC MRI may experience poorer hearing outcomes. To detect such abnormal findings, it is recommended to perform IAC MRI early after the onset of ISSNHL.

Bony cochlear nerve canal and internal auditory canal measures predict cochlear nerve status

2017 ◽  
Vol 131 (8) ◽  
pp. 676-683 ◽  
Author(s):  
E Tahir ◽  
M D Bajin ◽  
G Atay ◽  
B Ö Mocan ◽  
L Sennaroğlu
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Temporal Bone ◽  
Internal Auditory Canal ◽  
Cochlear Nerve ◽  
Resonance Imaging ◽  
Canal Stenosis ◽  
Canal Diameter ◽  
Canal Atresia

AbstractObjectives:The bony cochlear nerve canal is the space between the fundus of the internal auditory canal and the base of the cochlear modiolus that carries cochlear nerve fibres. This study aimed to determine the distribution of bony labyrinth anomalies and cochlear nerve anomalies in patients with bony cochlear nerve canal and internal auditory canal atresia and stenosis, and then to compare the diameter of the bony cochlear nerve canal and internal auditory canal with cochlear nerve status.Methods:The study included 38 sensorineural hearing loss patients (59 ears) in whom the bony cochlear nerve canal diameter at the mid-modiolus was 1.5 mm or less. Atretic and stenotic bony cochlear nerve canals were examined separately, and internal auditory canals with a mid-point diameter of less than 2 mm were considered stenotic. Temporal bone computed tomography and magnetic resonance imaging scans were reviewed to determine cochlear nerve status.Results:Cochlear hypoplasia was noted in 44 out of 59 ears (75 per cent) with a bony cochlear nerve canal diameter at the mid-modiolus of 1.5 mm or less. Approximately 33 per cent of ears with bony cochlear nerve canal stenosis also had a stenotic internal auditory canal and 84 per cent had a hypoplastic or aplastic cochlear nerve. All patients with bony cochlear nerve canal atresia had cochlear nerve deficiency. The cochlear nerve was hypoplastic or aplastic when the diameter of the bony cochlear nerve canal was less than 1.5 mm and the diameter of the internal auditory canal was less than 2 mm.Conclusion:The cochlear nerve may be aplastic or hypoplastic even if temporal bone computed tomography findings indicate a normal cochlea. If possible, patients scheduled to receive a cochlear implant should undergo both computed tomography and magnetic resonance imaging of the temporal bone. The bony cochlear nerve canal and internal auditory canal are complementary structures, and both should be assessed to determine cochlear nerve status.

Magnetic resonance imaging versus computed tomography in pre-operative evaluation of cochlear implant candidates with congenital hearing loss

2002 ◽  
Vol 116 (10) ◽  
pp. 804-810 ◽  
Author(s):  
Levent Sennaroglu ◽  
Isil Saatci ◽  
Ayse Aralasmak ◽  
Bulent Gursel ◽  
Ergin Turan
Keyword(s):  
Magnetic Resonance Imaging ◽  
Hearing Loss ◽  
Magnetic Resonance ◽  
Cochlear Implant ◽  
Sensorineural Hearing Loss ◽  
Internal Auditory Canal ◽  
Cochlear Nerve ◽  
Sensorineural Hearing ◽  
Congenital Hearing Loss ◽  
Resonance Imaging

Recent reports indicate that the cochlear nerve may be absent in some cases of congenital sensorineural hearing loss. The aim of this prospective study was to determine the incidence of cochlear nerve anomaly in cochlear implant candidates with congenital hearing loss using magnetic resonance imaging (MRI). Twenty-seven patients with congenital profound bilateral sensorineural hearing loss who were being evaluated for the cochlear implant procedure were studied.These patients had high-resolution computerized tomography (CT), through the petrous bone in axial sections. MRI examinations consisted of T1 and turbo spin echo (TSE) T2-weighted 3 mm axial images, and additional 3D Fourier Transform T2-weighted TSE sequences obtained on three different planes (axial, perpendicular and parallel to the internal auditory canal (IAC) i.e. oblique sagittal and coronal, respectively) for the purpose of cochlear nerve demonstration. Results showed that all of the 14 patients with normal CT of the temporal bone, had four distinct nerves in the distal part of the IAC on TSE-MRI. Thirteen patients demonstrated various bony malformations of the cochleovestibular system on CT. MRI revealed the absence of the cochleovestibular nerve in four patients where the IAC was very narrow or completely absent on CT. One patient with severe Mondini malformation who had an enlarged IAC demonstrated an isolated absent cochlear nerve.

Technical Aspects on Magnetic Resonance Imaging of the Spine at 1.5 Tesla

1987 ◽  
Vol 28 (4) ◽  
pp. 375-381 ◽  
Author(s):  
S. L. Holtås ◽  
D. B. Plewes ◽  
J. H. Simon ◽  
S. Ekholm ◽  
D. K. Kido ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Image Quality ◽  
Surface Coil ◽  
Motion Artifacts ◽  
The Body ◽  
Acquisition Time ◽  
Slice Thickness ◽  
Resonance Imaging ◽  
Technical Aspects

Technical aspects on surface coil magnetic resonance imaging of the spine using a superconducting system with a field strength of 1.5 tesla are described. By using a flat surface coil instead of the body coil the image quality was markedly improved and the signal-to-noise ratio (S/N) was increased approximately 2.6 times. Small voxels resulted in low S/N. The best image quality was achieved with a slice thickness of 5 mm, a field of view of 20 to 24 cm and a matrix of 256×256. Interleaved slices provided superior image quality compared with contiguous slices at the expense of acquisition time. For sagittal images the phase encoding gradient should be in the cranio-caudal direction to minimize motion artifacts. To obtain T1 and T2 images of high quality, spin echo pulse sequences with TR 600/TE 20 ms and TR 2000/TE 40 to 80 ms are useful.

scholarly journals Surface-coil magnetic resonance imaging of the internal auditory canal

1985 ◽  
Vol 145 (3) ◽  
pp. 469-472 ◽  
Author(s):  
DL Daniels ◽  
JF Schenck ◽  
T Foster ◽  
H Hart ◽  
SJ Millen ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Internal Auditory Canal ◽  
Surface Coil ◽  
Resonance Imaging

scholarly journals Arachnoid Cysts of the Internal Auditory Canal: Multiplanar Magnetic Resonance Imaging With Audio‐Vestibular Correlates

2021 ◽  
Author(s):  
Arianna Di Stadio ◽  
Laura Dipietro ◽  
Daniela Messineo ◽  
Massimo Ralli ◽  
Giampietro Ricci ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Internal Auditory Canal ◽  
Arachnoid Cysts ◽  
Resonance Imaging

Cochlear nerve anomalies in paediatric single-sided deafness – prevalence and implications for cochlear implantation strategies

2020 ◽  
pp. 1-4
Author(s):  
K Pollaers ◽  
A Thompson ◽  
J Kuthubutheen
Keyword(s):  
Magnetic Resonance Imaging ◽  
Hearing Loss ◽  
Magnetic Resonance ◽  
Sensorineural Hearing Loss ◽  
Cochlear Nerve ◽  
Sensorineural Hearing ◽  
Resonance Imaging ◽  
Bilateral Sensorineural Hearing Loss ◽  
Single Sided Deafness ◽  
Cochlear Nerve Hypoplasia

Abstract Objective To determine the prevalence of cochlear nerve anomalies on magnetic resonance imaging in patients with unilateral or bilateral sensorineural hearing loss. Methods A retrospective case series was conducted at a tertiary referral centre. The inclusion criteria were paediatric patients with bilateral or unilateral sensorineural hearing loss, investigated with magnetic resonance imaging. The primary outcome measure was the rate of cochlear nerve hypoplasia or aplasia. Results Of the 72 patients with unilateral sensorineural hearing loss, 39 per cent (28 cases) had absent or hypoplastic cochlear nerves on the affected side. Fifteen per cent (11 cases) had other abnormal findings on magnetic resonance imaging. Eighty-four patients had bilateral sensorineural hearing loss, of which cochlear nerve hypoplasia or aplasia was identified only in 5 per cent (four cases). Other abnormal findings were identified in 14 per cent (12 cases). Conclusion Paediatric patients with unilateral sensorineural hearing loss are more likely to have cochlear nerve anomalies than those patients with bilateral sensorineural hearing loss. This has important implications regarding cochlear implantation for patients with single-sided deafness.

Magnetic Resonance Imaging of Spinal Cord Disease of Childhood

PEDIATRICS ◽  
1986 ◽  
Vol 78 (2) ◽  
pp. 251-256
Author(s):  
Roger J. Packer ◽  
Robert A. Zimmerman ◽  
Leslie N. Sutton ◽  
Larissa T. Bilaniuk ◽  
Derek A. Bruce ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Spinal Cord ◽  
Magnetic Resonance ◽  
Vertebral Body ◽  
Congenital Anomalies ◽  
Correct Diagnosis ◽  
Surface Coil ◽  
Resonance Imaging ◽  
Spinal Cord Disease ◽  
Magnetic Resonance Imaging Mri

Correct diagnosis of spinal cord disease in childhood is often delayed, resulting in irreversible neurologic deficits. A major reason for this delay is the lack of a reliable means to noninvasively visualize the spinal cord. Magnetic resonance imaging (MRI) should be useful in the evaluation of diseases of the spinal cord. A 1.5 Tesla MRI unit with a surface coil was used to study 41 children, including eight patients with intrinsic spinal cord lesions, eight patients with masses compressing the cord, 12 patients with congenital anomalies of the cord or surrounding bony structures, three patients with syrinxes, and three patients with vertebral body abnormalities. Intrinsic lesions of the cord were well seen in all cases as intrinsic irregularly widened, abnormally intense cord regions. MRI was helpful in following the course of disease in patients with primary spinal cord tumors. Areas of tumor were separable from syrinx cavities. Extrinsic lesions compressing the cord and vertebral body disease were also well visualized. Congenital anomalies of the spinal cord, including tethering and lipomatous tissue, were better seen on MRI than by any other radiographic technique. MRI is an excellent noninvasive "screening" technique for children with suspected spinal cord disease and may be the only study needed in many patients with congenital spinal cord anomalies. It is also an excellent means to diagnose and follow patients with other forms of intra- and extraspinal pathology.

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