Pictorial review of MRI/CT Scan in congenital temporal bone anomalies, in patients for cochlear implant

Advanced Omics Techniques for Understanding Cochlear Genome, Epigenome, and Transcriptome in Health and Disease

Advanced genomics, transcriptomics, and epigenomics techniques are providing unprecedented insights into the understanding of the molecular underpinnings of the central nervous system, including the neuro-sensory cochlea of the inner ear. Here, we report for the first time a comprehensive and updated overview of the most advanced omics techniques for the study of nucleic acids and their applications in cochlear research. We describe the available in vitro and in vivo models for hearing research and the principles of genomics, transcriptomics, and epigenomics, alongside their most advanced technologies (like single-cell omics and spatial omics), which allow for the investigation of the molecular events that occur at a single-cell resolution while retaining the spatial information.

MRI of the Internal Auditory Canal, Labyrinth, and Middle Ear: How We Do It

MRI is firmly established as an essential modality in the imaging of the temporal bone and lateral skull base. It is used to evaluate normal anatomic structures, evaluate for vestibular schwannomas, assess for inflammatory and/or infectious processes, and detect residual and/or recurrent cholesteatoma. It is also extensively used in pre- and postoperative evaluations, particularly in patients with vestibular schwannomas and candidates for cochlear implantation. Nevertheless, despite the widespread use of MRI for these purposes, many radiologists remain unfamiliar with the complex anatomy and expected imaging findings with such examinations. The purpose of this review is to provide an overview of the most useful MRI sequences for internal auditory canal and labyrinthine imaging, review the relevant anatomy, and discuss the expected appearances of the most commonly encountered pathologic entities. In addition, the features at pre- and postprocedural MRI will be discussed to help ensure that diagnostic radiologists may be of greatest use to the ordering physicians. © RSNA, 2020.

Does the Width of the Bony Cochlear Nerve Canal Predict the Outcomes of Cochlear Implantation?

A narrow bony cochlear nerve canal (BCNC) is associated with sensorineural hearing loss necessitating cochlear implantation (CI). This study evaluated the implications of BCNC width for post-CI outcomes. A total of 56 children who had received CIs were included. The patients were divided into three groups according to the width of the BCNC (Group 1: diameter < 1.4 mm, n = 17; Group 2: diameter 1.4-2.0 mm, n = 14; Group 3: diameter > 2.0 mm, n = 25). The post-CI speech performances were compared among the three groups according to BCNC width. The correlation between BCNC width and post-CI speech performance was evaluated. Logistic regression analysis was also performed to investigate factors that can impact post-CI speech performance. Cochlear nerve deficiency (CND) occurred more frequently in Group 1. Groups 1 and 2 had significantly worse post-CI outcomes. Patients with intact cochlear nerves had significantly better post-CI outcomes than those with CND. When the cochlear nerve was intact, patients with a narrower BCNC showed less favorable results. Therefore, patients with either a narrow BCNC or CND seemed to have poorer outcomes. A narrow BCNC is associated with higher CND rates and poor outcomes. Measurement of BCNC diameter may help predict CI outcomes.

Diagnosis and Treatment of Congenital Sensorineural Hearing Loss

Purpose of Review

The aim of this report is to review current literature regarding the work-up and management of congenital sensorineural hearing loss.

Recent Findings

Diagnostic evaluation of a newborn with sensorineural hearing loss begins with a complete audiologic evaluation and comprehensive history and physical exam. This review presents a diagnostic algorithm for the work-up of congenital hearing loss, focusing on the three following modalities: cytomegalovirus testing, genetic evaluation, and imaging.

Summary

Newborn hearing loss is a common problem and may be attributed to genetic and non-genetic factors. Complete diagnostic evaluation and treatment are essential for preventing delays in language development. Treatment consists of early intervention services and consideration of hearing aid amplification and cochlear implantation.

Determining compliance of ear CT scan with interaoperative findings in deaf children with cochlear implantation

INTRODUCTION

Defecated or impaired hair cell function of the cochlea causes deafness. Cochlear implantation allows transmission of sound information through central auditory pathways using direct electric stimulation of auditory nerve dendrites. Using radiologic imaging, including CT scan is very helpful in selection of candidates and evaluation after implantation. The purpose of this study is to determine compliance of CT findings in deaf children undergoing cochlear implantation compared with the intra-operative findings.

METHOD

In a periodical-descriptive study, 100 patients (56 male and 44 female), 6 months to 6 years of age, who were candidates for cochlear implantation at Baqiyatallah Hospital in Tehran between January 2010 and October 2011, were studied. After getting informed consent form the parents of patients, demographic data was recorded. CT scan and surgical data were double blindly collected in the designed questionnaire which was approved by three radiologists and three ENT specialists. Finally, surgical and radiological data were compared and t-test and chi-square test was used.

RESULTS

Atic status in 89 patients (89%) was statistically significant between radiology and surgery (P=0.06). Positive Predictive Value and Negative Predictive Value were respectively 100 and 92.8. Middle ear space was same in 85 patients (85%) in the two methods (P=0.01) (NVP=63.4). Pyramid status was similar in radiology and surgery results in 67 patients (67%) (P=0.000) and PPV and NPV were 100 and 63.4 respectively. Jugular bulb was similar in 73 patients (73%) (P=0.00). There was no significant difference between other modalities.

CONCLUSION

In most cases examined in this study, compliance between the surgical and radiological findings was above 80%. In some cases, CT scan could give confidence to the surgeon, but in atic, middle ear space, pyramid and jugular bulb there might be insufficient reliance to CT findings and there would be need to more accurate observation during surgery.

Temporal bone imaging

Temporal bone imaging is performed for a variety of clinical conditions addressed in the outpatient and acute care setting ranging from hearing loss to trauma. Recent advances in magnetic resonance technology have enhanced the assessment of fine anatomic temporal bone detail and improved the diagnostic sensitivity for important pathology. For example, non-echo planar diffusion weighted imaging increases detection rate and diagnostic confidence of recurrent cholesteatoma. This chapter will focus on relevant temporal bone clinical entities and new MR developments that have come into clinical practice.

High resolution multi detector computed tomography of temporal bone: our experience in a tertiary care service hospital

High resolution multi detector computed tomography (HRMDCT) is an excellent tool for evaluation of a variety of congenital and acquired conditions affecting the temporal bones. We describe our experience of HRMDCT of temporal bones of 145 patients in a tertiary care and teaching hospital of Armed Forces Medical Services of India over a period of three and half years. Hearing loss was the most frequent indication for HRMDCT and congenital bilateral profound sensorineural hearing loss for evaluation prior to possible cochlear implant formed the single largest group (62, 42%) among all indications for HRMDCT of temporal bones. Major vestibule-cochlear and semicircular canal anomalies were noted in 11 such cases. Seven patients of microtia were studied and all had positive CT scan findings. All patients of vertigo had normal HRCT study. Extent of temporal bone injuries and inflammatory conditions were clearly delineated in all cases. Thinner collimations allowing image reconstructions in planes of anatomical interest with near isotropic resolution has been a major advantage of HRMDCT of temporal bones.

CT and MR imaging of the inner ear and brain in children with congenital sensorineural hearing loss

Imaging plays an important role in the evaluation of congenital sensorineural hearing loss. In children who are candidates for cochlear implantation surgery, it provides vital preoperative information about the inner ear, the vestibulocochlear nerve, and the brain. High-resolution computed tomography (CT) and magnetic resonance (MR) imaging provide excellent delineation of the intricate anatomy of the inner ear: CT depicts the minute details of osseous structures, and MR imaging allows visualization of the fluid-filled spaces and the vestibulocochlear nerve. Together, these complementary modalities can aid decision making about the best management strategy by facilitating the identification and characterization of inner ear malformations and any associated neurologic abnormalities. It is important that the radiologist be familiar with the key imaging features when interpreting CT and MR images obtained in this patient group. A broad spectrum of inner ear malformations have been described and linked to developmental insults at different stages of embryogenesis, and various systems have been proposed for classifying them. In this article, these malformations are described by using classification systems used by otolaryngologists for ease of interpretation. The relevant normal anatomy and development of the inner ear are briefly surveyed, standard imaging protocols for studying the inner ear are reviewed, and the imaging appearances of frequently observed inner ear malformations are described and illustrated. The impact of the identification of these malformations and commonly associated brain abnormalities on clinical management and prognosis also is discussed.