Volumetric Rendering of Human Inner Ear by MR Imaging

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P103-P103
Author(s):  
Jen-Fang Yu ◽  
Wei-Chung Chin ◽  
Che-Ming Wu ◽  
Shu-Hang Ng
Keyword(s):  
Mr Imaging ◽  
Inner Ear ◽  
3D Model ◽  
Semicircular Canals ◽  
Vestibular Aqueduct ◽  
3D Geometry ◽  
Large Vestibular Aqueduct Syndrome ◽  
Volumetric Rendering ◽  
Human Inner Ear

Problem To non-invasively measure in-vivo human inner ear by MRI and measure the geometry of vestibule by the reconstructed 3D model of inner ear for further diagnosis of large vestibular aqueduct syndrome (LVAS). Methods 3-T MR scanner, MAGNETOM Trio made by Siemens, was utilized. The TR/TE for MR imaging of 7 patients was 5.65/2.6 ms and the voxel size was 0.5 mm X 0.5 mm X 0.5 mm for single slice of 48 slices. The configuration of semicircular canals, vestibule and cochlea could be detected by threshold. The 3D geometry of inner ear was then computed based on the thickness of slice. Results The surface area and volume of semicircular canals for 7 normal ears were 217.85 square mm and 63.56 cubic mm; of vestibule were 105.88 square mm and 56.36 cubic mm; of cochlea were 171.84 square mm and 81.29 cubic mm respectively. The variation of volumes of vestibule and cochlea could be quantified non-invasively. The correlation between the volume and the level of LVAS will be analyzed once the number of volunteer reaches a statistically significant level. Conclusion The variation for the geometry of vestibule could be measured non-invasively. The grade of LVAS can be assessed by the obtained 3D model of semi-circular canal, vestibule and cochlea. Significance According to the 3D model, the geometry of inner ear can be measured, and the syndrome can be revealed directly to help clinical diagnosis of LVAS more accurately.

Measurement of the Human Cochlear Spiral Curvature In Vivo

2013 ◽  
Vol 284-287 ◽  
pp. 1552-1558
Author(s):  
Jen Fang Yu ◽  
Kun Che Lee
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Inner Ear ◽  
Cochlear Implantation ◽  
Resonance Imaging ◽  
Basal Turn ◽  
Magnetic Resonance Imaging Mri ◽  
Human Inner Ear

This research aims to characterize the geometry of the human cochlear spiral in vivo by measuring curvature and length. Magnetic resonance imaging (MRI) was used to visualise the human inner ear in vivo. The inner ear was imaged in 12 ears in 7 subjects recruited. Visualisation of the cochlear spiral was enhanced by T2 weighting and further processing of the raw images. The spirals were divided into 3 segments: the basal turn segment, the middle turn segment and the apex turn segment. The length and curvature of each segment were measured. The measured lengths of cochlear spiral are consistent with data in the literature derived from anatomical dissections. Overall, the apex turn segment of the cochlear had the greatest degree of curvature. A detailed description of the cochlear spiral is provided, using measurements of curvature and length. This data will provide a valuable reference in the development of cochlear implantation procedures.

scholarly journals Arenysaurus ardevoli, first paleoneuroanatomical description of a European hadrosaurid

2014 ◽  
Author(s):  
Penélope Cruzado-Caballero ◽  
Josep Fortuny ◽  
Sergio Llacer ◽  
José Ignacio JI Canudo
Keyword(s):  
North America ◽  
Inner Ear ◽  
Late Cretaceous ◽  
Cerebral Hemisphere ◽  
3D Model ◽  
General Pattern ◽  
Semicircular Canals ◽  
Major Axis ◽  
Ontogenetic Stage ◽  
And Behavior

The neuroanatomy of hadrosaurid dinosaurs is well known from North America and Asia. In Europe only a few cranial remains have been recovered with the braincase. Arenysaurus is the first European endocast for which the paleoneuroanatomy has been studied. The resulting data have enabled us to draw ontogenetic, phylogenetic and functional inferences. Arenysaurus preserves the endocast and the inner ear. This cranial material was CT-scanned, and a 3D-model was generated. The endocast morphology supports a general pattern for hadrosaurids with some characters that distinguish to a subfamily level, such as a brain cavity anteroposteriorly shorter or the angle of the major axis of the cerebral hemisphere to the horizontal in lambeosaurines. Both characters are present in the endocast of Arenysaurus. Moreover, osteological features indicate an adult ontogenetic stage while some paleoneuroanatomical features are indicative of a subadult ontogenetic stage and even a juvenile ontogenetic stage. Finally, a comparison with other hadrosaurids reveals that the low values for the angle of the dural peak may be an autapomorphy exclusive to the Parasaurolophus genus. It is hypothesized that the presence of puzzling characters that suggest different ontogenetic stages for this specimen, may reflect some degree of dwarfism in Arenysaurus. Regarding the inner ear, its structure shows differences from the ornithopod clade with respect to the height of the semicircular canals. These differences could lead to a decrease in the compensatory movements of eyes and head, with important implications for the paleobiology and behavior of hadrosaurid taxa such as Edmontosaurus, Parasaurolophus and Arenysaurus. These differences in the vestibular system could be used as a phylogenetical signal. The endocranial morphology of European hadrosaurids sheds new light on the evolution of this group and may reflect the conditions in the archipelago where these animals lived during the Late Cretaceous.

scholarly journals Proteomics and the Inner Ear

2001 ◽  
Vol 17 (4) ◽  
pp. 259-270 ◽  
Author(s):  
Isolde Thalmann
Keyword(s):  
Inner Ear ◽  
Calcium Binding ◽  
Angular Acceleration ◽  
Organ Of Corti ◽  
Semicircular Canals ◽  
Frequency Discrimination ◽  
Receptor System ◽  
Perilymphatic Fistula ◽  
Proteomics Approach

The inner ear, one of the most complex organs, contains within its bony shell three sensory systems, the evolutionary oldest gravity receptor system, the three semicircular canals for the detection of angular acceleration, and the auditory system - unrivaled in sensitivity and frequency discrimination. All three systems are susceptible to a host of afflictions affecting the quality of life for all of us. In the first part of this review we present an introduction to the milestones of inner ear research to pave the way for understanding the complexities of a proteomics approach to the ear. Minute sensory structures, surrounded by large fluid spaces and a hard bony shell, pose extreme challenges to the ear researcher. In spite of these obstacles, a powerful preparatory technique was developed, whereby precisely defined microscopic tissue elements can be isolated and analyzed, while maintaining the biochemical state representative of thein vivoconditions. The second part consists of a discussion of proteomics as a tool in the elucidation of basic and pathologic mechanisms, diagnosis of disease, as well as treatment. Examples are the organ of Corti proteins OCP1 and OCP2, oncomodulin, a highly specific calcium-binding protein, and several disease entities, Meniere's disease, benign paroxysmal positional vertigo, and perilymphatic fistula.

scholarly journals Clinical Investigation and Mechanism of Air-Bone Gaps in Large Vestibular Aqueduct Syndrome

2007 ◽  
Vol 116 (7) ◽  
pp. 532-541 ◽  
Author(s):  
Saumil N. Merchant ◽  
Hideko H. Nakajima ◽  
Christopher Halpin ◽  
Joseph B. Nadol ◽  
Daniel J. Lee ◽  
...  
Keyword(s):  
Inner Ear ◽  
Middle Ear ◽  
Bone Conduction ◽  
Distortion Product Otoacoustic Emission ◽  
Low Frequencies ◽  
Distortion Product ◽  
Vestibular Aqueduct ◽  
Acoustic Reflexes ◽  
Large Vestibular Aqueduct Syndrome ◽  
Large Vestibular Aqueduct

Objectives: Patients with large vestibular aqueduct syndrome (LVAS) often demonstrate an air-bone gap at the low frequencies on audiometric testing. The mechanism causing such a gap has not been well elucidated. We investigated middle ear sound transmission in patients with LVAS, and present a hypothesis to explain the air-bone gap. Methods: Observations were made on 8 ears from 5 individuals with LVAS. The diagnosis of LVAS was made by computed tomography in all cases. Investigations included standard audiometry and measurements of umbo velocity by laser Doppler vibrometry (LDV) in all cases, as well as tympanometry, acoustic reflex testing, vestibular evoked myogenic potential (VEMP) testing, distortion product otoacoustic emission (DPOAE) testing, and middle ear exploration in some ears. Results: One ear with LVAS had anacusis. The other 7 ears demonstrated air-bone gaps at the low frequencies, with mean gaps of 51 dB at 250 Hz, 31 dB at 500 Hz, and 12 dB at 1,000 Hz. In these 7 ears with air-bone gaps, LDV showed the umbo velocity to be normal or high normal in all 7; tympanometry was normal in all 6 ears tested; acoustic reflexes were present in 3 of the 4 ears tested; VEMP responses were present in all 3 ears tested; DPOAEs were present in 1 of the 2 ears tested, and exploratory tympanotomy in 1 case showed a normal middle ear. The above data suggest that an air-bone gap in LVAS is not due to disease in the middle ear. The data are consistent with the hypothesis that a large vestibular aqueduct introduces a third mobile window into the inner ear, which can produce an air-bone gap by 1) shunting air-conducted sound away from the cochlea, thus elevating air conduction thresholds, and 2) increasing the difference in impedance between the scala vestibuli side and the scala tympani side of the cochlear partition during bone conduction testing, thus improving thresholds for bone-conducted sound. Conclusions: We conclude that LVAS can present with an air-bone gap that can mimic middle ear disease. Diagnostic testing using acoustic reflexes, VEMPs, DPOAEs, and LDV can help to identify a non?middle ear source for such a gap, thereby avoiding negative middle ear exploration. A large vestibular aqueduct may act as a third mobile window in the inner ear, resulting in an air-bone gap at low frequencies.

scholarly journals IE-Map: A novel in-vivo atlas template of the human inner ear

2019 ◽  
Author(s):  
Seyed-Ahmad Ahmadi ◽  
Theresa Raiser ◽  
Ria Maxine Rühl ◽  
Virginia L. Flanagin ◽  
Peter zu Eulenburg
Keyword(s):  
Inner Ear ◽  
Normal Subjects ◽  
Intracranial Volume ◽  
Imaging Data ◽  
Magnetic Resonance Imaging Data ◽  
Non Invasive ◽  
Substructure Analysis ◽  
Auditory Organ ◽  
Human Inner Ear

AbstractBrain atlases and templates are core tools in scientific research with increasing importance also in clinical applications. Advances in neuroimaging now allowed us to expand the atlas domain to the vestibular and auditory organ, the inner ear. In this study, we present IE-Map, an in-vivo template and atlas of all known substructures of the human labyrinth derived from multi-modal high-resolution magnetic resonance imaging data in a non-invasive manner (no contrast agent or radiation). We reconstructed a common template from 126 inner ears (63 normal subjects) and annotated it with 94 established landmarks and semi-automatic segmentations. Quantitative substructure analysis revealed a correlation of labyrinth parameters with total intracranial volume. No effects of gender or laterality were found. We provide the validated templates, atlas segmentations, surface meshes and landmark annotations as open-access material, to provide neuroscience researchers and clinicians in neurology, neurosurgery, and otorhinolaryngology with a widely applicable tool for computational neurootology.

scholarly journals Experimental Fusion of Contrast Enhanced High-Field Magnetic Resonance Imaging and High-Resolution Micro-Computed Tomography in Imaging the Mouse Inner Ear

2015 ◽  
Vol 9 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Allen Counter S ◽  
Peter Damberg ◽  
Sahar Nikkhou Aski ◽  
Kálmán Nagy ◽  
Cecilia Engmér Berglin ◽  
...  
Keyword(s):  
High Resolution ◽  
Inner Ear ◽  
High Field ◽  
Ex Vivo ◽  
Semicircular Canals ◽  
Vestibular Apparatus ◽  
Resonance Imaging ◽  
Micro Computed Tomography ◽  
Ultra High Field

Objective: Imaging cochlear, vestibular, and 8th cranial nerve abnormalities remains a challenge. In this study, the membranous and osseous labyrinths of the wild type mouse inner ear were examined using volumetric data from ultra high-field magnetic resonance imaging (MRI) with gadolinium contrast at 9.4 Tesla and high-resolution micro-computed tomography (µCT) to visualize the scalae and vestibular apparatus, and to establish imaging protocols and parameters for comparative analysis of the normal and mutant mouse inner ear. Methods: For in vivo MRI acquisition, animals were placed in a Milleped coil situated in the isocenter of a horizontal 9.4 T Varian magnet. For µCT examination, cone beam scans were performed ex vivo following MRI using the µCT component of a nanoScan PET/CT in vivo scanner. Results: The fusion of Gd enhanced high field MRI and high-resolution µCT scans revealed the dynamic membranous labyrinth of the perilymphatic fluid filled scala tympani and scala vestibule of the cochlea, and semicircular canals of the vestibular apparatus, within the µCT visualized contours of the contiguous osseous labyrinth. The ex vivo µCT segmentation revealed the surface contours and structural morphology of each cochlea turn and the semicircular canals in 3 planes. Conclusions: The fusion of ultra high-field MRI and high-resolution µCT imaging techniques were complementary, and provided high-resolution dynamic and static visualization of the complex morphological features of the normal mouse inner ear structures, which may offer a valuable approach for the investigation of cochlear and vestibular abnormalities that are associated with birth defects related to genetic inner ear disorders in humans.

scholarly journals Incomplete Partition type I: Radiological Evaluation of the Temporal Bone

Acta Medica ◽  
2021 ◽  
pp. 1-9
Author(s):  
Safak Parlak ◽  
Ayca Akgoz Karaosmanoglu ◽  
Sevtap Arslan ◽  
Levent Sennaroglu
Keyword(s):  
Inner Ear ◽  
Temporal Bone ◽  
Correct Diagnosis ◽  
Semicircular Canals ◽  
Type I ◽  
Vestibular Aqueduct ◽  
Endolymphatic Duct ◽  
Incomplete Partition ◽  
Internal Acoustic Canal ◽  
Large Vestibular Aqueduct

Objective: Incomplete partition type I is an uncommon congenital anomaly of the inner ear, characterized by typical cystic cochleovestibular appearance. Incomplete partition type I was firstly defined as cystic cochlea and vestibule without large vestibular aqueduct; however, large vestibular aqueduct and/or enlarged endolymphatic duct could rarely be seen in incomplete partition type I anomaly. Correct diagnosis of the type of cochlear malformation and differentiation of incomplete partition type I is necessary for patient management and surgical approach. Our aim was to document the temporal bone imaging findings in a series of patients with incomplete partition type I. Materials and Methods: CT (n=85) and/or MRI (n=80) examinations of 99 ears in 59 incomplete partition type I patients were retrospectively evaluated. All structures of the otic capsule were retrospectively assessed. The appearances of cochlea and vestibule, vestibular aqueduct/endolymphatic duct, semicircular canals were qualitatively evaluated by an experienced neuroradiologist. The vertical dimension of vestibular aqueduct and/or endolymphatic duct (from the point where the duct arises from the vestibule) was measured on CT/MRI. Anterior-posterior diameter of the internal acoustic canal and the diameter of cochlear aperture were measured on CT. The cochleovestibular nerves were evaluated on sagittal-oblique high T2-weighted imaging. Results: All 99 ears had defective partition with unpartitioned cochlear basal turn and absent interscalar septae, separated but cystic cochlea. The vestibule was enlarged in all ears except one. Semicircular canals were usually dysplastic (92.9%). A total of 35 incomplete partition type I ears (35.3%) had large vestibular aqueduct and/or enlarged endolymphatic duct. Internal acoustic canal was wide in 21% of ears. Cochlear aperture was wide in 5.9% of ears. Cochlear nerve was either hypoplastic or aplastic in about a quarter of incomplete partition type I ears. Conclusion: In up to one-third of incomplete partition type I patients, an associated large vestibular aqueduct /endolymphatic duct could be seen accompanying typical inner ear findings. Although the cochlear nerves are normal in the majority of cases, auditory brainstem implantation may be necessary in certain cases of incomplete partition type I anomaly.

scholarly journals Visualization of Human Inner Ear Anatomy with High-Resolution MR Imaging at 7T: Initial Clinical Assessment

2014 ◽  
Vol 36 (2) ◽  
pp. 378-383 ◽  
Author(s):  
M.A. van der Jagt ◽  
W.M. Brink ◽  
M.J. Versluis ◽  
S.C.A. Steens ◽  
J.J. Briaire ◽  
...  
Keyword(s):  
High Resolution ◽  
Mr Imaging ◽  
Inner Ear ◽  
Clinical Assessment ◽  
Human Inner Ear

scholarly journals The Spectrum and Frequency of Inner Ear Anomalies in Patients with Congenital Hearing Impairment in Yakutia

2020 ◽  
Vol 101 (2) ◽  
pp. 90-102
Author(s):  
L. A. Klarov ◽  
N. A. Barashkov ◽  
F. M. Teryutin ◽  
G. P. Romanov ◽  
M. M. Popov ◽  
...  
Keyword(s):  
Inner Ear ◽  
Hearing Impairment ◽  
Temporal Bone ◽  
Semicircular Canals ◽  
Internal Auditory Meatus ◽  
X Ray ◽  
Vestibular Aqueduct ◽  
Incomplete Partition ◽  
Ear Anomalies ◽  
Congenital Hearing Impairment

Objective. To analyze the spectrum and frequency of inner ear anomalies in patients with congenital hearing impairment in Yakutia.Material and methods. A total of 165 patients with congenital hearing impairment were surveyed. All the patients were examined by an audiologist, an educational audiologist, and a neuropsychiatrist. All the patients underwent X-ray computed tomography (X-ray CT) of temporal bone structures (which was supplemented by magnetic resonance imaging (MRI) in some cases).Results. Based on modern ideas about inner ear anomalies and their classification, the authors first analyzed the spectrum and frequency of inner ear anomalies in patients with congenital hearing impairment in Yakutia. Inner ear malformations were identified in 16 (9.7%) of the 165 patients with hearing impairment, which corresponds to that in the previously studied samples of deaf people in different countries (from 3% to 35%). Of the inner ear structures, the cochlea and vestibule were more commonly affected. Abnormalities of the internal auditory meatus, semicircular canals, and vestibular aqueduct were less common. In general, the spectrum of anomalies was represented by 7 different malformations. Incomplete partition type II (IP-II) (34.3%) came first in incidence among all the abnormalities. Incomplete partition type III (IP-III) (18.7%) ranked second in incidence. The expansion of the internal auditory meatus (12.5%) and vestibular aqueduct (12.5%) occupied the third place. Inner ear anomalies occurred as concurrences that are difficult to interpret and classify in half (50%) of all the cases.Conclusion. Analysis of the spectrum and frequency of temporal bone abnormalities in Yakutia suggests that every 10 patients with congenital hearing impairment have one or another inner ear structural malformation (9.7%) and require accurate and timely diagnosis using up-to-date X-ray CT and MRI techniques.

Geometrical Scaling for the Measurement of In-Vivo Human Inner Ear

2012 ◽  
Vol 10 (5) ◽  
pp. 1247-1251
Author(s):  
Jen-Fang Yu ◽  
Kun-Che Lee ◽  
Wei-Chung Chin
Keyword(s):  
Inner Ear ◽  
Geometrical Scaling ◽  
Human Inner Ear
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