A Post-processing Protocol for Three-dimensional Visualization of the Inner Ear Using the Volume-rendering Technique Based on a Standard Magnetic Resonance Imaging Protocol

A superior diagnostic quality compared to other post-processing (PP) techniques for three-dimensional (3D) inner ear imaging has been attributed to volume rendering (VR). We defined and assessed a VR protocol for 3D visualization of the inner ear in a routine imaging setting. Following definition of a VR protocol by using lower threshold values, surface shading, perspective views and related parameters, standardized 3D views of the inner ear were generated and evaluated in 32 patients suffering from sensorineural or combined hearing loss. Comprehensive inner ear visualization was achieved in 28 patients by means of two 3D shaded-surface views. Incomplete data acquisition (1/32), motion and pulsation artefacts (2/32) and interposed fluid-retaining mastoid cells (1/32) were responsible for non-diagnostic image quality in 4/32 patients. In 5/32 patients modifications of the PP protocol involving the threshold value and depth-cueing parameters helped to establish diagnostic image quality. Mean post-processing time amounted to 5.8 min per site. 3D imaging with the VR technique is suitable for routine inner ear assessment if direct VR, predefined PP protocols and standardized labyrinthine views are used.     

High-resolution petrous bone imaging using multi-slice computerized tomography

Multi-slice computerized tomography (MSCT) is considered to provide superior image quality. We defined a data acquisition protocol for high-resolution (HR) temporal bone imaging using MSCT and assessed its impact on data acquisition and post-processing (PP). The data acquisition protocol was defined in cadaveric phantom studies performed by MSCT and subsequently applied to 38 patients referred for temporal bone assessment. The parameters image quality and diagnostic value of MSCT data were assessed for the cross-sectional source images as well as for 2-dimensional (2D) reformations and 3-dimensional (3D) reconstructions by 3 radiologists by comparison with incremental HR scans of 17 patients with suspected middle ear disorders. The data acquisition protocol yielded HR images with an excellent detail resolution and a comparable image quality of cross-sectional scans and related orthogonal reformations. MSCT achieved higher scores for image quality and diagnostic value (p < 0.001, t-test) than incremental HR CT with regard to both 2D and 3D reconstructions. MSCT improves the image quality of HR cross-sectional scans as well as that of 2D and 3D PP techniques in petrous bone imaging. The radiation exposure of the eye lenses is increased by MSCT as gantry angulation is not yet possible in the helical scan mode.     

High-resolution Petrous Bone Imaging Using Multi-slice Computerized Tomography

Multi-slice computerized tomography (MSCT) is considered to provide superior image quality. We defined a data acquisition protocol for high-resolution (HR) temporal bone imaging using MSCT and assessed its impact on data acquisition and post-processing (PP). The data acquisition protocol was defined in cadaveric phantom studies performed by MSCT and subsequently applied to 38 patients referred for temporal bone assessment. The parameters image quality and diagnostic value of MSCT data were assessed for the cross-sectional source images as well as for 2-dimensional (2D) reformations and 3-dimensional (3D) reconstructions by 3 radiologists by comparison with incremental HR scans of 17 patients with suspected middle ear disorders. The data acquisition protocol yielded HR images with an excellent detail resolution and a comparable image quality of cross-sectional scans and related orthogonal reformations. MSCT achieved higher scores for image quality and diagnostic value (p &lt; 0.001, t-test) than incremental HR CT with regard to both 2D and 3D reconstructions. MSCT improves the image quality of HR cross-sectional scans as well as that of 2D and 3D PP techniques in petrous bone imaging. The radiation exposure of the eye lenses is increased by MSCT as gantry angulation is not yet possible in the helical scan mode.     

3D-Visualisation of the middle ear by computer-assisted post-processing of helical multi-slice CT data

Post-processing of CT-data allows non-invasive 3D-Visualisation of the middle ear for diagnosis and surgical planning. In this study different post-processing techniques and the clinical application of a 3D-postprocessing algorithm in a large number of patients are presented. 20 normal patients, 6 dissected temporal bones and 213 patients with suspected middle ear pathology were examined using a low-dosage Multi-Slice CT protocol. Virtual endoscopic views of the middle ear and 3D-images of the ossicles were generated using a standardised algorithm. Evaluation of the image quality was performed. The virtual views of the dissected temporal bones were compared to real views. In 32 patients high-quality 3D-models of the individual anatomical structures were generated and displayed using different visualisation techniques. The standardised and evaluated method enabled visualisation of the normal middle ear anatomy. Assessment of different pathologies, especially malformation, trauma, implants and postoperative alterations, was facilitated. The high-quality 3D-models allowed precise imaging of the anatomical structures. 3D-Visualisation of the middle ear using CT-data is beneficial for radiological diagnosis and surgical planning in cases of complex middle ear pathology as a complementary examination technique.     

Three-dimensional imaging of the inner ear by volume-rendered reconstructions of magnetic resonance data

OBJECTIVE: To evaluate 3-dimensional inner ear visualization by volume rendering of high-resolution magnetic resonance data in patients with clinically suspected inner ear abnormality. DESIGN: Prospective comparative study of different postprocessing techniques, based on blinded film readings. SETTING: Tertiary referral hospital. SUBJECTS: Fifty patients (17 females and 33 males) aged 1 to 77 years (average age, 42 years) with sensorineural hearing loss, vertigo, and/or tinnitus. INTERVENTION: Postprocessing of magnetic resonance data to inner ear reconstructions by the use of volume rendering as well as maximum-intensity projection; caloric testing by electronystagmography. MAIN OUTCOME MEASURES: Film was read blindly by 4 radiologists using a 5-point parameter scale for image quality and diagnostic value. The assessibility of inner ear subsegments was evaluated. The specificity of volume-rendered reconstructions for detecting semicircular canal obliterations was assessed in a subgroup of 9 patients by caloric testing. The time required for data postprocessing as well as film reading was recorded by means of a stopwatch. RESULTS: Volume-rendered inner ear reconstructions were superior in image quality (P<.001), diagnostic value (P<.001), subsegment inner ear assessment (P<.01 to P<.001), and film reading time (P<.001) compared with maximum-intensity projections. The data postprocessing time was comparable for both techniques. Caloric weakness was noted in all patients assessed by electronystagmography. CONCLUSION: Volume rendering is the postprocessing technique of choice for 3-dimensional inner ear visualization, performing better than maximum-intensity projections with respect to various parameters.     

高分辨率CT容积重建对内耳畸形的诊断价值

目的：通过高分辨率CT（HRCT）容积重建（VR）对正常内耳形态的观察,探讨其对先天性内耳畸形的诊断价值。方法：对10例（20耳）无耳部疾患者（对照组）和7例（11耳）先天性内耳畸形患者（病变组）行HRCT扫描,利用容积漫游技术对内耳骨迷路重建。对照组观察内耳骨迷路的正常结构,病变组观察内耳畸形情况。结果：正常耳VR图像不但显示了内耳骨迷路的细微结构,而且还反映了各结构之间的关系;病变耳立体显示了畸形部位及程度。11耳患耳中Mondini型7耳次;前庭及半规管畸形3耳次;前庭导水管扩大7耳次,其中6耳次伴随其他畸形;内耳道畸形2耳次且均伴随其他畸形。11耳畸形中9耳HRCT横断面图像和平面重建（MPR）冠状位图像、VR图像均可以清晰地显示畸形的部位和程度,其中VR图像可以直观、立体地显示畸形的空间形态结构;2耳水平半规管短小畸形患者VR图像较断面图像更好地显示了畸形的部位和程度。结论：VR三维重建可以立体显示正常内耳骨迷路的形态,直观显示内耳畸形的程度及病变位置,对内耳畸形的诊断具有重要的辅助价值。     

经鼓室注射内耳钆造影显影不良原因初探

目的 总结分析经鼓室注射内耳钆造影显影不良的可能原因,探讨可行的解决方案。 方法 分析经鼓室注射内耳钆造影的356例患者(共706耳)病历资料,发现存在显影不良55例(共70耳),分析显影不良可能存在的原因。 结果 55例(共70耳)中表现为显影浅淡16耳,表现为充盈欠佳14耳,不显影/未见造影剂充盈40耳。影像学提示单纯合并同侧中耳炎者39耳,考虑慢性中耳炎或隐匿性中耳炎,其中出现显影不良11耳(约28.2%,11/39);单纯合并鼻窦炎者32耳,出现显影不良4耳(约12.5%,4/32);同时合并中耳炎和鼻窦炎者3耳,出现显影不良者1耳(约33.3%,1/3);影像学未提示合并中耳炎/鼻窦炎者632耳,其中出现显影不良54耳(约8.5%,54/632)。合并中耳炎与未合并相比差异有统计学意义,合并鼻窦炎、同时合并中耳炎鼻窦炎与未合并比较差异无统计学意义。 结论 经鼓室注射内耳钆造影时,排除近期中耳炎病史后,慢性中耳炎或隐匿性中耳炎仍可能是显影不良的影响因素。通过对造影各个环节中其他可能存在的影响因素进行进一步探讨,建议根据可能存在的原因尽量规避,以提高内耳钆造影的成功率。     

Virtual rendering techniques in otologic imaging

Virtual postprocessing techniques combine the advantages of condensing the large amounts of data provided by high-resolution (HR) cross-sectional imaging modalities with those of three-dimensional (3D) imaging. The techniques and indications for virtual representations in imaging of the middle ear (ME), internal ear (IE), and cerebellopontine angle (CPA) are presented together with practical examples. MATERIAL AND METHODS: HR data sets acquired by computed tomography (CT) and magnetic resonance imaging (MRI) in patients with ME, IE, and CPA pathologies were transferred to a workstation via an internal network to generate endo- or extraluminal 3D views by means of the volume rendering technique (VRT). The source data were acquired using scanners and imaging protocols with the highest resolution available at present: a multislice spiral CT (MSCT) with a slice thickness of 0.5 mm and a reconstruction increment of 0.2 mm and a 3D CISS sequence with a slice thickness of 0.5 mm for MRI. RESULTS: Virtual endoscopy was superior to cross-sectional images for assessing ME pathologies like dysplasia, postoperative changes, and destructive bone processes with extensive soft-tissue involvement; fibrous obliterations of the internal ear and labyrinthine dysplasia were depicted with a superior image quality on 3D renderings compared to conventional reconstruction techniques. Virtual endoscopy of the CPA and external acoustic meatus (EAM) was helpful in detecting and visualizing neurovascular conflicts and in assigning small intrameatal tumors to components of the acousticofacial bundle. A common feature of all applications was that the large numbers of source images could be reduced to a few 3D reconstructions for documentation and optimized communication of the findings between the radiologist and otologist. CONCLUSION: Virtual rendering makes an important contribution towards establishing, presenting, and documenting the findings when certain otologic pathologies have to be assessed. It can be used for routine imaging and allows for more efficient handling of the large amounts of imaging data generated by high-resolution cross-sectional imaging modalities.     

MSCT多模态三维重建观测颞骨结构及对人工耳蜗手术的指导意义

目的 探讨采用MSCT影像三维多模态重建技术在人工耳蜗植入术术前评估、术后复查中的应用价值.方法 ①应用双阈值重建技术显示耳蜗、前庭、半规管的膜性立体结构及听小骨,颞骨透明成像,逐一融合显示听小骨、内耳与颞骨的关系;②面神经曲面重建显示面神经的走行,观察面神经与面神经隐窝、外耳道后壁、鼓索神经等邻近结构的关系;③双斜径多平面重建(MPR)技术测量鼓岬平面面神经垂直段与鼓索神经的距离.结果 该组83例,内耳畸形11例中Mondini畸形2例、半规管畸形2例、共同腔畸形2例、内听道狭窄1例、前庭导水管扩大4例.正常结构耳鼓岬平面面神经垂直段与鼓索神经距离左侧(0.270±0.057)cm,右侧(0.280±0.068)cm.术后复查5例,清晰显示植入电极位置良好.结论 多模态重建技术能较好地满足临床多角度、全方位观察中耳和内耳解剖的需要,评估手术风险,确保手术顺利进行并可应用于术后复查植入电极的位置.     

A new approach to visualizing the membranous structures of the inner ear - high resolution X-ray micro-tomography

CONCLUSION: Through the application of high resolution X-ray micro-tomography and a method of contrast enhancement based on en bloc staining in osmium tetroxide (OsO4), we report an approach that facilitates accurate three-dimensional (3D) reconstruction to reveal the fine structure of the inner ear. OBJECTIVES: To overcome the problems of artefacts, including tissue distortion and loss of 3D context that are inherent in existing methods that rely on manual dissection and/or histological sectioning. MATERIALS AND METHODS: A staining protocol was developed that involved the en bloc application of the OsO4 solution (2% w/v) for an extended period of time. The samples were then scanned using an X-ray micro-tomography platform and subsequent 3D visualizations were constructed. RESULTS: The digital nature of the data allowed a complete 3D contextual visualization to be constructed whereby the individual sensory structures could be seen in relation to other inner ear structures. This included a detailed anatomy of the membranous labyrinth and nerve supply including the spatial configuration of the utricular and saccular maculae. This is a new way of undertaking temporal bone histology.     

人工耳蜗植入术后植入电极的影像学检查

目的 探讨建立螺旋CT扫描及三维重建技术观察人工耳蜗植入电极方法，并比较X线摄片方法与螺旋CT扫描三维重建方法的耳蜗内电极的影像学特征及其临床应用价值。方法 18例人工耳蜗植入患者全部作术后X线摄片检查。其中9例用经眼眶前后位摄片，9例采用侧斜位60。摄片。3例患者施行术后螺旋CT扫描及内耳三维重建方法。结果 2种投射头位的X线摄片均可显示电极形态及单个电极对，可间接判断电极在耳蜗内的植入深度。螺旋CT扫描三维重建图可直观地显示耳蜗形态、电极形态及其在耳蜗内植入的深度，可清晰识别单个电极对。结论 螺旋CT扫描三维重建方法可直观观察植入电极的形态及位置，可准确判断电极在耳蜗内植入的深度，有其独特的临床应用价值。     

Virtual reality modelling language: freely available cross-platform visualization technique for 3-D visualization of the inner ear

This was a study of the use of virtual reality modelling language (VRML) for cross-platform interactive three-dimensional (3-D) visualization of high-resolution magnetic resonance (MR) images of the inner ear in the assessment of cochlear implant candidates. A retrospective case review was made of cochlear implant candidates undergoing pre-operative high-resolution MR studies to determine their suitability for implantation. 3-D visualizations of MR scans of the inner ear structures were created using surface rendering and exported as portable VRML files. Case studies are presented to illustrate different points of interest. VRML reconstructions aided the interpretation of two-dimensional (2-D) source images in a variety of inner ear abnormalities. VRML is an internationally recognized standard for cross-platform 3-D visualization that creates a means of providing the implanting surgeon with a portable 3-D representation of the inner ear, aiding interpretation of the complex cross-sectional anatomy of these structures, and guiding selection of patients for implantation as well as implantation technique. The elucidation of the mechanisms behind inner ear malformations can also be aided by detailed imaging studies of the temporal bone, with VRML reconstructions providing an easily interpreted representation of deformities.     

Overview of new methods of operating field visualization in inner ear surgery

New methods of 3D visualization in operating field give better possibilities in different surgical specialties. Authors analyzed current optical systems for choosing assumption of the method to better visualize the inner ear intraoperatively. For practical clinical reasons optimal imaging of the inner ear is possible with additional digital processing on the display fitted to the head of the operating microscope.     

Visualization of endolymphatic hydrops in patients with Meniere's disease

OBJECTIVE: Recently, there have been many reports of intratympanic gentamicin therapy for the treatment of intractable Meniere's disease. Intratympanic administration of steroids has also been used to treat sudden sensorineural hearing loss. We attempted to visualize how the intratympanically administered drug enters the inner ear. METHODS: Gadolinium hydrate diluted eightfold with saline was injected intratympanically through the tympanic membrane using a 23 G needle in nine patients with inner ear diseases. With a 3 Tesla magnetic resonance imaging (MRI) unit, three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) imaging was performed. RESULTS: 3D-FLAIR MRI clearly revealed that the gadolinium entered the perilymphatic space and delineated the perilymphatic and endolymphatic spaces of the inner ear. In patients with endolymphatic hydrops, the perilymphatic space surrounding the endolymph was small or had disappeared. Gadolinium appeared first in the scala tympani of the basal turn of the cochlea and the perilymphatic space of the vestibule. One day after the intratympanic injection of gadolinium, the gadolinium was observed in almost all parts of the perilymph. Six days after the intratympanic injection, the gadolinium had almost disappeared from the inner ear. CONCLUSION: We reported the first visualization of endolymphatic hydrops in patients with Meniere's disease. The relationship between the image of the endolymphatic space and functional tests, such as electrocochleography and vestibular-evoked myogenic potential, must be examined in the near future. It is important for the development of intratympanic drug therapies for inner-ear diseases to investigate how the drugs enter and leave the inner ear.     

Three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging findings and prognosis in sudden sensorineural hearing loss

Objectives/Hypothesis: Three‐dimensional fluid‐attenuated inversion recovery (3D‐FLAIR) magnetic resonance imaging (MRI) has recently been developed to detect high concentrations of protein or hemorrhage. We have previously reported that 50% of patients with sudden sensorineural hearing loss (SNHL) show high signals in the affected inner ear on 3D‐FLAIR MRI. However, the relationship between 3D‐FLAIR findings and hearing prognosis is unclear. Our objective was to evaluate the relationship between the results of 3D‐FLAIR MRI at 3 Tesla and prognosis in sudden SNHL. Study Design and Methods: We used 3D‐FLAIR at 3 Tesla with and without gadolinium enhancement to evaluate the pathologic conditions in the inner ears of 48 patients with sudden SNHL. Results: Thirty‐one of 48 patients with sudden SNHL showed high signals in the affected inner ear on precontrast 3D‐FLAIR. Hearing improvement in patients with high signals in the affected inner ear on precontrast 3D‐FLAIR (25 ± 19 dB) was significantly worse than that in patients with no signal (45 ± 27 dB; P < .05). Our analysis suggests that high signals in the affected inner ear on precontrast 3D‐FLAIR MRI is a new prognostic factor for sudden SNHL. Conclusions: 3D‐FLAIR findings show that high signals in the cochlea on precontrast 3D‐FLAIR are related to a poor hearing prognosis. These signals may reflect minor hemorrhage or an increased concentration of protein in the inner ear, which has passed through blood vessels with increased permeability or has originated in disrupted cells in the inner ear.     

Use of laboratory evaluation and radiologic imaging in the diagnostic evaluation of children with sensorineural hearing loss.

OBJECTIVE: Laboratory testing and radiologic imaging are commonly used to delineate syndromic from nonsyndromic sensorineural HL (SNHL). The aim of this study was to examine the yield of laboratory tests and radiologic imaging commonly used in the diagnostic evaluation of SNHL in children. STUDY DESIGN: Retrospective analysis of 114 (54 female, 60 male) consecutively investigated children with SNHL between 1998 and 2000 at a tertiary-care university hospital. METHODS: Results of routine laboratory testing to assess autoimmunity, blood dyscrasias, endocrine abnormalities, renal function, infection, and cardiac testing were reviewed. Results of radiologic evaluation were also reviewed. In general, computed tomography (CT) was obtained in patients with symmetric SNHL, whereas magnetic resonance imaging (MRI) with or without CT was obtained in asymmetric SNHL. RESULTS: Laboratory evaluation of the blood did not yield the etiology of SNHL in any patient. Blood tests for autoimmune disease were often positive but did not correlate with clinical disease. Nonspecific elevation of erythrocyte sedimentation rate (ESR) and antinuclear antibody (ANA) was present in 22% of cases. An abnormal electrocardiogram with a prolonged QT interval resulted in the diagnosis of Jervall and Lange-Nielsen syndrome. In the 97 patients who underwent radiologic studies, abnormalities were present in 38 of 97 studies (39%). Isolated inner ear malformations were twice as common as multiple abnormalities with large vestibular aqueducts as the most common isolated finding. CONCLUSION: In the evaluation of children with unexplained SNHL, routine laboratory evaluation should be reconsidered given its low diagnostic yield. However, radiologic abnormalities of the inner ear are common. Identification of inner ear malformations has direct impact on management of these children, suggesting that all children should undergo radiologic imaging as an integral component of evaluation of SNHL.     

Inner ear dysplasia is common in children with Down syndrome (trisomy 21)

OBJECTIVES/HYPOTHESIS: Middle and external ear anomalies are well recognized in Down syndrome (DS, trisomy 21). Inner ear anomalies are much less frequently described. This study reviews inner ear morphology on imaging to determine the prevalence of cochlear and vestibular anomalies in children with DS. STUDY DESIGN: The authors conducted a retrospective review of imaging features of (DS) inner ear structures. METHODS: Fifty-nine sequential patients with DS with imaging of the inner ear were identified by a radiology report text search program. Quantitative biometric assessment of the inner ear was performed on patients with high-resolution computed tomography or magnetic resonance images of the petrous bone. Petrous imaging was performed for evaluation of inflammatory disease or hearing loss. Spinal imaging, which included petrous views, was performed in most cases to exclude C1 to 2 dislocation, a potential complication of DS. Measurements were compared with normative data. RESULTS: Inner ear dysplasia is much more common in DS than previously reported. Inner ear structures are universally hypoplastic. Vestibular malformations are particularly common and a small bony island of the lateral semicircular canal (<3 mm in diameter) appears highly typical. Additional findings in some patients were persistent lateral semicircular anlage with fusion of the lateral semicircular canal and vestibule into a single cavity, vestibular aqueduct and endolymphatic sac fossa enlargement, cochlear nerve canal hypoplasia, and stenosis or duplication of the internal auditory canal. Stenosis of the external meatus, poor mastoid pneumatization, middle ear and mastoid opacification, and cholesteatoma were common, as expected.     

A new approach to visualizing the membranous structures of the inner ear – high resolution X-ray micro-tomography

Conclusion. Through the application of high resolution X-ray micro-tomography and a method of contrast enhancement based on en bloc staining in osmium tetroxide (OsO₄), we report an approach that facilitates accurate three-dimensional (3D) reconstruction to reveal the fine structure of the inner ear. Objectives. To overcome the problems of artefacts, including tissue distortion and loss of 3D context that are inherent in existing methods that rely on manual dissection and/or histological sectioning. Materials and methods. A staining protocol was developed that involved the en bloc application of the OsO₄solution (2% w/v) for an extended period of time. The samples were then scanned using an X-ray micro-tomography platform and subsequent 3D visualizations were constructed. Results. The digital nature of the data allowed a complete 3D contextual visualization to be constructed whereby the individual sensory structures could be seen in relation to other inner ear structures. This included a detailed anatomy of the membranous labyrinth and nerve supply including the spatial configuration of the utricular and saccular maculae. This is a new way of undertaking temporal bone histology.     

CT三维重建对人工耳蜗植入术后电极位置的观察

目的：探讨建立CT扫描及三维重建技术观察人工耳蜗植入（CI）电极的方法,并比较不同CT扫描三维重建方法的耳蜗内植入电极的影像学特征及其临床应用价值。方法：6例CI患者全部作术后CT扫描并分别应用多层面重建的容积再现（VR）、平均密度投影（AIP）、表面遮盖显示技术（SSD）3种方法进行三维重建,观察人工耳蜗植入术后耳蜗内电极。结果：3种方法的三维重建图均可直观地显示电极形态、走行及其在耳蜗内植入的深度和植入电极与内耳的空间关系,并可清晰识别耳蜗内的电极数目。结论：CT扫描三维重建方法可直接观察植入电极的形态及位置,可准确判断电极在耳蜗内电极数目,有其独特的临床应用价值。     

Topographic analysis of inner ear lesions in profoundly deafened patients with tympanogenic and meningogenic labyrinthitis using three-dimensional magnetic resonance imaging.

OBJECTIVE: High-resolution magnetic resonance imaging (MRI) provided clear images of three-dimensional (3D) reconstruction of the inner ear in candidates for cochlear implantation. In this study. semiquantitative analysis of the 3D MRI findings was performed to investigate topographic lesions of the inner ear caused by tympanogenic and meningogenic labyrinthitis. STUDY DESIGN: This was an observational study. SETTING: The study was performed in an academic, comprehensive, multispecialty group practice. PATIENTS: Postlingual deafened patients with cochlear implantation. The cause of deafness was tympanogenic or meningogenic labyrinthitis. INTERVENTION: High-resolution 3D MRI and postoperative speech recognition tests were used. RESULTS: Abnormal findings in the inner ear detected with MRI were found before surgery in 58.3% of the patients with meningogenic labyrinthitis, although the incidence was lower in patients with tympanogenic labyrinthitis. Abnormal MRI findings were frequently observed in the cochlear basal turn and semicircular canals more than in the middle and apical turn in cases with meningogenic etiology. Patients with tympanogenic labyrinthitis suffered less with a vestibular apparatus than did those patients with meningogenic labyrinthitis. Regarding the analysis of the inner ear lesions at the implanted side, the postoperative speech recognition ability did not correlate to the extent of abnormal MRI findings of the implanted ear. CONCLUSION: Improvement in 3D MRI technology provided an accurate preoperative picture of the inner ear apparatus. In cochlear implant patients with infectious labyrinthitis, the extent of the inner ear lesion detected with 3D MRI was different among etiologies of deafness.