RESUMEN
OBJECTIVES: The internal acoustic meatus is an osseous canal that connects the inner ear to the posterior cranial fossa. It is located in the petrous portion of the temporal bone. A thin cribriform osseous plate known as the fundus is situated at the lateral end of the canal. This study assesses the structural and numerical variations of the fundus formations. METHODS: Fifty-four temporal bones of unknown gender and age were examined with the surgical microscope. RESULTS: The temporal bones analyzed were 46.2% right-sided and 53.7% left-sided. Only one temporal bone had two parallel transverse crests, while three had a single anterior crest that split into two branches posteriorly. The number of foramina at the transverse crest varied, with 29.6% having none, 48.1% having a single foramen, and 22.2% having several foramina. An anterior crest structure was seen in 53.7% of the temporal bones, with 5% having a slightly constricted entry to the facial canal. In cases with a single nerve foramen, 48.1% had one, while 51.8% had more than one, including examples with three or four foramina. A crest was found between the foramina of the single nerve in 7% of patients. Furthermore, a crest between the saccular nerve foramen and the high fiber foramina was seen in 25.9% of cases, and 5% had two saccular nerve foramina. CONCLUSION: We think that revealing the anatomical, structural and numerical variations in the fundus will be useful in explaining the disease-symptom relationship. LEVEL OF EVIDENCE: Level 4.
Asunto(s)
Hueso Temporal , Humanos , Hueso Temporal/anatomía & histología , Variación Anatómica , Conducto Auditivo Externo/anatomía & histología , Masculino , Femenino , Oído Interno/anatomía & histología , Oído Interno/diagnóstico por imagenRESUMEN
The endocranial structures of the sebecid crocodylomorph Zulmasuchus querejazus (MHNC 6672) from the Lower Paleocene of Bolivia are described in this article. Using computed tomography scanning, the cranial endocast, associated nerves and arteries, endosseous labyrinths, and cranial pneumatization are reconstructed and compared with those of extant and fossil crocodylomorphs, representative of different ecomorphological adaptations. Z. querejazus exhibits an unusual flexure of the brain, pericerebral spines, semicircular canals with a narrow diameter, as well as enlarged pharyngotympanic sinuses. First, those structures allow to estimate the alert head posture and hearing capabilities of Zulmasuchus. Then, functional comparisons are proposed between this purportedly terrestrial taxon, semi-aquatic, and aquatic forms (extant crocodylians, thalattosuchians, and dyrosaurids). The narrow diameter of the semicircular canals but expanded morphology of the endosseous labyrinths and the enlarged pneumatization of the skull compared to other forms indeed tend to indicate a terrestrial lifestyle for Zulmasuchus. Our results highlight the need to gather new data, especially from altirostral forms in order to further our understanding of the evolution of endocranial structures in crocodylomorphs with different ecomorphological adaptations.
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Evolución Biológica , Dinosaurios/anatomía & histología , Fósiles/anatomía & histología , Canales Semicirculares/anatomía & histología , Cráneo/diagnóstico por imagen , Animales , Arterias/anatomía & histología , Arterias/diagnóstico por imagen , Bolivia , Encéfalo/anatomía & histología , Encéfalo/diagnóstico por imagen , Vértebras Cervicales/anatomía & histología , Vértebras Cervicales/diagnóstico por imagen , Nervios Craneales/anatomía & histología , Nervios Craneales/diagnóstico por imagen , Senos Craneales/anatomía & histología , Senos Craneales/diagnóstico por imagen , Dinosaurios/fisiología , Oído Interno/anatomía & histología , Oído Interno/diagnóstico por imagen , Fósiles/diagnóstico por imagen , Audición , Estilo de Vida , Postura , Canales Semicirculares/diagnóstico por imagen , Cráneo/anatomía & histología , Cráneo/irrigación sanguínea , Tomógrafos Computarizados por Rayos XRESUMEN
The evaluation of internal auditory canals and cochlea has gained significant importance due to the increasing number of cochlear implantations worldwide. This region's anatomical study is essential for cochlear implant surgery using magnetic resonance imaging as the method of choice. We report a case of a 6-year-old male patient diagnosed with a rare bilateral malformation of the internal auditory canals associated with an aberrant course of the facial nerve and vestibulocochlear nerve aplasia. This report raises the importance of identifying this rare malformation for appropriate management and reinforces awareness of possible complications.
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Oído Interno/anomalías , Enfermedades del Nervio Facial/diagnóstico , Enfermedades del Nervio Vestibulococlear/diagnóstico , Niño , Oído Interno/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , MasculinoRESUMEN
Middle- and inner-ear surgery is a vital treatment option in hearing loss, infections, and tumors of the lateral skull base. Segmentation of otologic structures from computed tomography (CT) has many potential applications for improving surgical planning but can be an arduous and time-consuming task. We propose an end-to-end solution for the automated segmentation of temporal bone CT using convolutional neural networks (CNN). Using 150 manually segmented CT scans, a comparison of 3 CNN models (AH-Net, U-Net, ResNet) was conducted to compare Dice coefficient, Hausdorff distance, and speed of segmentation of the inner ear, ossicles, facial nerve and sigmoid sinus. Using AH-Net, the Dice coefficient was 0.91 for the inner ear; 0.85 for the ossicles; 0.75 for the facial nerve; and 0.86 for the sigmoid sinus. The average Hausdorff distance was 0.25, 0.21, 0.24 and 0.45 mm, respectively. Blinded experts assessed the accuracy of both techniques, and there was no statistical difference between the ratings for the two methods (p = 0.93). Objective and subjective assessment confirm good correlation between automated segmentation of otologic structures and manual segmentation performed by a specialist. This end-to-end automated segmentation pipeline can help to advance the systematic application of augmented reality, simulation, and automation in otologic procedures.
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Automatización/métodos , Hueso Temporal/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Oído Interno/diagnóstico por imagen , Oído Interno/cirugía , Oído Medio/diagnóstico por imagen , Oído Medio/cirugía , Nervio Facial/diagnóstico por imagen , Nervio Facial/cirugía , Humanos , Periodo Preoperatorio , Hueso Temporal/cirugíaRESUMEN
OBJECTIVES: Focal hyperintensity in the dorsal brainstem (HDB) has been described in large cerebellopontine angle tumours and is thought to represent vestibular nuclei degeneration, but its functional significance has not been thoroughly investigated. Our aim was to analyse its relationship to imaging characteristics of the tumour and inner-ear structures and to vestibulocochlear functional tests. METHODS: We retrospectively reviewed 54 patients with a histological diagnosis of vestibular schwannoma (VS). Magnetic resonance imaging tumour characteristics (size, cystic composition and distance from the cochlear aperture), signal intensity ratio of the cochlea and vestibule in fluid-attenuated inversion recovery (FLAIR) and fast imaging employing steady-state acquisition (FIESTA)/fast spin-echo imaging with variable flip angles (CUBE) and vestibulocochlear function tests (audiometry, auditory brainstem response (ABR) and video head impulse testing (vHIT)) were obtained. Statistical analyses were performed to evaluate their relation to focal HDB. RESULTS: Focal HDB was found in 22% of VS. It was significantly associated with large (p < 0.001) and cystic (p = 0.004) tumours and also with tumours located further from the cochlear aperture (p = 0.039). The signal intensity ratio of the cochlea on FLAIR was higher in patients with HDB (p < 0.014), but this difference was not observed in FIESTA/CUBE (p = 0.981). Audiometry, ABR and vHIT results did not significantly differ in patients with HDB, but ABR results were worse in patients with higher cochlear signal intensity on FLAIR sequences (p = 0.026). CONCLUSIONS: Focal HDB in patients with VS was associated with increased signal intensity ratio of the cochlea on FLAIR in patients with VS but not directly to the results of vestibulocochlear function tests.
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Tronco Encefálico/diagnóstico por imagen , Oído Interno/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Neuroma Acústico/diagnóstico por imagen , Pruebas de Función Vestibular , Adolescente , Adulto , Anciano , Tronco Encefálico/patología , Medios de Contraste , Oído Interno/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neuroma Acústico/patología , Estudios RetrospectivosRESUMEN
OBJECTIVE: This study aims to investigate the application value of magnetic resonance (MR) hydrography of the inner ear in cochlear implantation. METHODS: 146 patients were enrolled. MR hydrography and spiral CT examinations for the intracranial auditory canal were performed before surgery, and all imaging results were statistically analyzed in order to explore the application value of MR hydrography of the inner ear in cochlear implantation. RESULTS: 146 patients (292 ears) were examined. Among these patients, 13 were diagnosed with abnormal vestibular aqueducts (20 ears) by MR hydrography, while five were diagnosed with this disease by CT; 15 patients were diagnosed with inner ear malformation (19 ears) by MR hydrography, while 11 were diagnosed by CT (four were misdiagnosed); five patients were diagnosed with internal acoustic canal stenosis (eight ears) by MR hydrography, while two were diagnosed by CT (three were misdiagnosed); and four patients were diagnosed with cochlear fibrosis (five ears) by MR hydrography, while four were diagnosed by CT (four ears). The correct rate of diagnosis was 77.40% (113/146) based on CT, while the rate was 93.84% (137/146) based on MR hydrography. CONCLUSIONS: MR hydrography imaging technique can be applied to the preoperative evaluation of cochlear implantation, providing accurate and reliable anatomic information on the inner membranous labyrinth and nerves in the internal acoustic canal and an accurate basis for the diagnosis of cochlear fibrosis and nerve development. This has a guiding significance for the selection of treatment schemes.
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Implantación Coclear/métodos , Oído Interno/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Adolescente , Adulto , Niño , Preescolar , Oído Interno/cirugía , Femenino , Pérdida Auditiva Sensorineural/diagnóstico por imagen , Pérdida Auditiva Sensorineural/cirugía , Humanos , Lactante , Enfermedades del Laberinto/diagnóstico por imagen , Enfermedades del Laberinto/cirugía , Masculino , Persona de Mediana Edad , Periodo Preoperatorio , Valores de Referencia , Reproducibilidad de los Resultados , Tomografía Computarizada Espiral/métodos , Adulto JovenRESUMEN
SUMMARY OBJECTIVE This study aims to investigate the application value of magnetic resonance (MR) hydrography of the inner ear in cochlear implantation. METHODS 146 patients were enrolled. MR hydrography and spiral CT examinations for the intracranial auditory canal were performed before surgery, and all imaging results were statistically analyzed in order to explore the application value of MR hydrography of the inner ear in cochlear implantation. RESULTS 146 patients (292 ears) were examined. Among these patients, 13 were diagnosed with abnormal vestibular aqueducts (20 ears) by MR hydrography, while five were diagnosed with this disease by CT; 15 patients were diagnosed with inner ear malformation (19 ears) by MR hydrography, while 11 were diagnosed by CT (four were misdiagnosed); five patients were diagnosed with internal acoustic canal stenosis (eight ears) by MR hydrography, while two were diagnosed by CT (three were misdiagnosed); and four patients were diagnosed with cochlear fibrosis (five ears) by MR hydrography, while four were diagnosed by CT (four ears). The correct rate of diagnosis was 77.40% (113/146) based on CT, while the rate was 93.84% (137/146) based on MR hydrography. CONCLUSIONS MR hydrography imaging technique can be applied to the preoperative evaluation of cochlear implantation, providing accurate and reliable anatomic information on the inner membranous labyrinth and nerves in the internal acoustic canal and an accurate basis for the diagnosis of cochlear fibrosis and nerve development. This has a guiding significance for the selection of treatment schemes.
RESUMO OBJETIVO Este estudo visa investigar o valor da aplicação da hidrografia por ressonância magnética (RM) do ouvido interno no implante coclear. MÉTODOS Cento e quarenta e seis pacientes foram inscritos. Os exames da hidrografia por RM e do CT espiral para o canal auditivo intracraniano foram executados antes da cirurgia, e todos os resultados da imagem foram analisados estatisticamente, a fim de explorar o valor da aplicação da hidrografia por RM do ouvido interno no implante coclear. RESULTADOS Centro e quarenta e seis pacientes (292 ouvidos) foram examinados. Dentre esses pacientes, 13 foram diagnosticados com aquedutos vestibulares anormais (20 ouvidos) pela hidrografia por RM, enquanto cinco pacientes foram diagnosticados com esta doença pelo CT; 15 pacientes foram diagnosticados com malformação do ouvido interno (19 ouvidos) pela hidrografia por RM, enquanto 11 pacientes foram diagnosticados por CT (quatro foram diagnosticados erroneamente); cinco pacientes foram diagnosticados com estenose de canal acústico interno (oito ouvidos) pela hidrografia por RM, enquanto dois pacientes foram diagnosticados por CT (três foram diagnosticados erroneamente); e quatro pacientes foram diagnosticados com fibrose coclear (cinco ouvidos) pela hidrografia por RM, enquanto quatro foram diagnosticados por CT (quatro ouvidos). A taxa correta de diagnóstico foi de 77,40% (113/146) com base no CT, enquanto a taxa foi de 93,84% (137/146) com base na hidrografia por RM. CONCLUSÕES A técnica de imagem da hidrografia por RM pode ser aplicada à avaliação pré-operatória do implante coclear, que pode fornecer informações anatômicas precisas e confiáveis sobre o labirinto membranoso interno e os nervos no canal acústico interno, além de uma base exata para o diagnóstico da fibrose coclear e do desenvolvimento do nervo. Isso tem um significado orientador para a seleção de esquemas de tratamento.
Asunto(s)
Humanos , Masculino , Femenino , Lactante , Preescolar , Niño , Adolescente , Adulto , Adulto Joven , Imagen por Resonancia Magnética/métodos , Implantación Coclear/métodos , Oído Interno/diagnóstico por imagen , Valores de Referencia , Reproducibilidad de los Resultados , Tomografía Computarizada Espiral/métodos , Periodo Preoperatorio , Pérdida Auditiva Sensorineural/cirugía , Pérdida Auditiva Sensorineural/diagnóstico por imagen , Oído Interno/cirugía , Enfermedades del Laberinto/cirugía , Enfermedades del Laberinto/diagnóstico por imagen , Persona de Mediana EdadRESUMEN
The development of inner ear gene carriers and delivery systems has enabled genetic defects to be repaired and hearing to be restored in mouse models. Today, promising advances in translational therapies provide confidence that targeted molecular therapy for inner ear diseases will be developed. Unfortunately, the currently available non-invasive modalities, such as Computerized Tomography scan or Magnetic Resonance Imaging provide insufficient resolution to identify most pathologies of the human inner ear, even when the current generation of contrast agents is utilized. The development of targeted contrast agents may play a critical role in determining the cause of, and treatment for, sensorineural hearing loss. Such agents should be able to pass through the cochlea barriers, possess minimal cytotoxicity, and easily conjugate to a targeting agent, without distorting the anatomic details. This review focuses on a series of contrast agents which may fit these criteria for potential clinical application.
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Oído Interno/patología , Pérdida Auditiva Sensorineural/fisiopatología , Imagen Molecular/métodos , Animales , Medios de Contraste/metabolismo , Oído Interno/diagnóstico por imagen , Oído Interno/metabolismo , HumanosAsunto(s)
Oído Interno/anomalías , Oído Interno/diagnóstico por imagen , Preescolar , Humanos , Masculino , RadiografíaRESUMEN
En candidatos a implante coclear con malformaciones del oído interno donde se encuentra un nervio coclear anormal, los estudios tradicionales y las imágenes muchas veces no pueden dar respuesta definitiva acerca de la funcionalidad y presencia del nervio coclear. Para esto ayudarían los estudios de electrofisiología. Se presentan tres casos clínicos de pacientes con malformaciones del oído interno que fueron evaluados con ePEAT para ayudar a determinar su candidatura a implante coclear. Los estudios electrofisiológicos no reemplazan a los estudios tradicionales de evaluación auditiva ni a los estudios por imágenes, sino que los complementan. Los casos presentados, demuestran que en casos de malformaciones de oído interno o CAI muy estrecho, en que se cuestiona seriamente la existencia de un nervio coclear funcional, y en casos de neuropatía auditiva, se hace necesario evaluar la función de la cóclea separadamente de la del nervio auditivo y la función del tronco. Para esto se utilizamos los ePEAT. Los ePEAT entregan información valiosísima ya que nos permite conocer las reales capacidades de los pacientes para transmitir un estímulo auditivo hacia el sistema nervioso central, definiendo mejor las expectativas con el uso implante, asistiéndonos en nuestra toma de decisiones.
In cochlear implant candidates with inner ear malformations, where there is an abnormal cochlear nerve, traditional studies and images cannot often provide definitive answers about the functionality and presence of the cochlear nerve. In these cases, electrophysiology studies can be used. We present 3 cases of patients with inner ear malformations who were evaluated with ePEAT to determine their candidacy for a cochlear implant. Electrophysiological studies do not replace traditional hearing screening studies or imaging studies, but complement them. The cases presented in this study demonstrate that in patients with inner ear malformations or very narrow internal auditory canal, where we question the existence of a functional cochlear nerve, and in cases of auditory neuropathy, it is necessary to evaluate the cochlear function separately from the auditory nerve and from the brainstem. In these cases we use ePEAT. ePEAT give us valuable information about the real abilities of patients to transmit an auditory stimulus to the central nervous system, which help us to define expectations with cochlear implant use, assisting us in our decision-making.
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Humanos , Masculino , Femenino , Preescolar , Niño , Selección de Paciente , Implantación Coclear/métodos , Estimulación Eléctrica/métodos , Oído Interno/anomalías , Oído Interno/fisiopatología , Imagen por Resonancia Magnética , Tomografía Computarizada por Rayos X , Cóclea/fisiopatología , Electrofisiología , Pérdida Auditiva Sensorineural/etiología , Oído Interno/diagnóstico por imagenRESUMEN
The purpose of this study is to provide a detailed description of the neuroanatomy of Bonatitan, Antarctosaurus, and an unnamed titanosaur from Río Negro, Argentina including the first observations on the inner ear of the two first taxa using CT scans. The materials were compared with previously described sauropod endocasts and other less complete titanosaur braincases from Argentina. The cranial endocasts show the general morphology of other sauropods being bulbous, anteroposteriorly short and transversely wide, and with enlarged and posteroventrally projected pituitary body. Particular titanosaur traits are the extremely short and horizontal olfactory tract, the absence of a floccular process and a single root for cranial nerve XII. In addition, in the basicranium the abducens nerve (CN VI) does not penetrates the pituitary fossa and the internal carotid artery enters the medial aspect of the basipterygoid process, resulting in an external opening for this vessel that is not visible in lateral view of the braincase. The titanosaurid inner ear also exhibits particular traits, such as robust semicircular canals, and anterior and posterior semicircular canals that are subequal in size. The variation observed in the sauropod endocranium indicates an evolutionary tendency in titanosaurs toward the anteroposterior shortening of the midbrain, and the reduction in size of the semicircular canals of the inner ear, in particular the anterior semicircular canal. This, together with the lack of floccular process suggests a narrower range of movements of the head for this clade.
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Encéfalo/anatomía & histología , Dinosaurios/anatomía & histología , Oído Interno/anatomía & histología , Cráneo/anatomía & histología , Animales , Argentina , Evolución Biológica , Encéfalo/diagnóstico por imagen , Dinosaurios/clasificación , Oído Interno/diagnóstico por imagen , Fósiles , Mesencéfalo/anatomía & histología , Tomografía Computarizada Multidetector , Paleontología , Prosencéfalo/anatomía & histología , Rombencéfalo/anatomía & histología , Cráneo/diagnóstico por imagen , Especificidad de la EspecieRESUMEN
BACKGROUND: Fishes show an amazing diversity in hearing abilities, inner ear structures, and otolith morphology. Inner ear morphology, however, has not yet been investigated in detail in any member of the diverse order Cyprinodontiformes. We, therefore, studied the inner ear of the cyprinodontiform freshwater fish Poecilia mexicana by analyzing the position of otoliths in situ, investigating the 3D structure of sensory epithelia, and examining the orientation patterns of ciliary bundles of the sensory hair cells, while combining µ-CT analyses, scanning electron microscopy, and immunocytochemical methods. P. mexicana occurs in different ecotypes, enabling us to study the intra-specific variability (on a qualitative basis) of fish from regular surface streams, and the Cueva del Azufre, a sulfidic cave in southern Mexico. RESULTS: The inner ear of Poecilia mexicana displays a combination of several remarkable features. The utricle is connected rostrally instead of dorso-rostrally to the saccule, and the macula sacculi, therefore, is very close to the utricle. Moreover, the macula sacculi possesses dorsal and ventral bulges. The two studied ecotypes of P. mexicana showed variation mainly in the shape and curvature of the macula lagenae, in the curvature of the macula sacculi, and in the thickness of the otolithic membrane. CONCLUSIONS: Our study for the first time provides detailed insights into the auditory periphery of a cyprinodontiform inner ear and thus serves a basis--especially with regard to the application of 3D techniques--for further research on structure-function relationships of inner ears within the species-rich order Cyprinodontiformes. We suggest that other poeciliid taxa, or even other non-poeciliid cyprinodontiforms, may display similar inner ear morphologies as described here.
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Oído Interno/anatomía & histología , Poecilia/anatomía & histología , Adaptación Fisiológica/efectos de los fármacos , Adaptación Fisiológica/efectos de la radiación , Animales , Oscuridad/efectos adversos , Oído Interno/diagnóstico por imagen , Oído Interno/fisiología , Oído Interno/ultraestructura , Epitelio/diagnóstico por imagen , Epitelio/ultraestructura , Femenino , Sulfuro de Hidrógeno/toxicidad , Inmunohistoquímica , Masculino , Microscopía Confocal , Microscopía Electrónica de Rastreo , Poecilia/fisiología , Especificidad de la Especie , Microtomografía por Rayos XRESUMEN
Los autores ofrecen un breve repaso de anatomía normal de la cóclea con imágenes de TC y RM a fin de posibilitar una más acabada identificación de hallazgos patológicos en pacientes con hipoacusia perceptiva (AU)