scholarly journals COMPUTER AIDED THREE-DIMENSIONAL RECONSTRUCTION AND MODELING OF MIDDLE EAR BIOMECHANICS BY HIGH-RESOLUTION COMPUTED TOMOGRAPHY AND FINITE ELEMENT ANALYSIS

2006 ◽  
Vol 18 (05) ◽  
pp. 214-221 ◽  
Author(s):  
CHIA-FONE LEE ◽  
PEIR-RONG CHEN ◽  
WEN-JENG LEE ◽  
JYH-HORNG CHEN ◽  
TIEN-CHEN LIU
Keyword(s):  
Computed Tomography ◽  
Finite Element Analysis ◽  
Finite Element ◽  
High Resolution ◽  
Temporal Bone ◽  
Middle Ear ◽  
Histological Section ◽  
Slice Thickness ◽  
High Resolution Computed Tomography ◽  
Element Analysis

In order to present a systematic and practical approach that uses high-resolution computed tomography (HRCT) to derive models of the middle ear for finite element analysis (FEA). This prospective study included 31 subjects with normal hearing and no previous otological disorders. Temporal bone images obtained from 15 right ears and 16 left ears were used for evaluation and reconstruction. High-resolution computed tomography of temporal bone was performed using simultaneous acquisition of 16 sections with a collimated slice thickness of 0.625 mm. All images were transferred to an Amira visualization system for 3D reconstruction. The created 3-D model was translated into two commercial modeling packages, Patran and ANSYS, for finite element analysis. The characteristic dimensions of the model were measured and compared with previous published histological section data. This result confirms that the geometric model created by the proposed method is accurate except the tympanic membrane is thicker than that of histological section method. No obvious difference in the geometrical dimension between right and left ossicles was found (p > 0.05). The 3D model created by finite element method and predicted umbo and stapes displacements are close to the bounds of the experimental curves of Nishihara's, Huber's, and Gan's data across the frequency range of 100-8000 Hz. The model includes a description of the geometry of the middle ear components, and dynamic equations of vibration. The proposed method is quick, practical, low cost and most importantly, non-invasive as compared with histological section methods.

scholarly journals Effects of Scan Resolutions and Element Sizes on Bovine Vertebral Mechanical Parameters from Quantitative Computed Tomography-Based Finite Element Analysis

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Meng Zhang ◽  
Jiazi Gao ◽  
Xu Huang ◽  
He Gong ◽  
Min Zhang ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Quantitative Computed Tomography ◽  
Slice Thickness ◽  
Mechanical Parameters ◽  
Ct Scanner ◽  
Computational Accuracy ◽  
Element Analysis ◽  
Vertebral Strength

Quantitative computed tomography-based finite element analysis (QCT/FEA) has been developed to predict vertebral strength. However, QCT/FEA models may be different with scan resolutions and element sizes. The aim of this study was to explore the effects of scan resolutions and element sizes on QCT/FEA outcomes. Nine bovine vertebral bodies were scanned using the clinical CT scanner and reconstructed from datasets with the two-slice thickness, that is, 0.6 mm (PA resolution) and 1 mm (PB resolution). There were significantly linear correlations between the predicted and measured principal strains (R2>0.7, P<0.0001), and the predicted vertebral strength and stiffness were modestly correlated with the experimental values (R2>0.6, P<0.05). Two different resolutions and six different element sizes were combined in pairs, and finite element (FE) models of bovine vertebral cancellous bones in the 12 cases were obtained. It showed that the mechanical parameters of FE models with the PB resolution were similar to those with the PA resolution. The computational accuracy of FE models with the element sizes of 0.41 × 0.41 × 0.6 mm3 and 0.41 × 0.41 × 1 mm3 was higher by comparing the apparent elastic modulus and yield strength. Therefore, scan resolution and element size should be chosen optimally to improve the accuracy of QCT/FEA.

scholarly journals High resolution computed tomography of temporal bone in the evaluation of otologic diseases

2017 ◽  
Vol 4 (1) ◽  
pp. 87
Author(s):  
Prakash S. Handi ◽  
Mallikarjun N. Patil ◽  
Nisha P.
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Ct Scan ◽  
Temporal Bone ◽  
Middle Ear ◽  
Tertiary Care ◽  
Age Groups ◽  
Tertiary Care Centre ◽  
High Resolution Computed Tomography ◽  
Bone Anomalies

<p class="abstract"><strong>Background:</strong> <span lang="EN-IN">Conventional radiological methods like X-ray mastoid have limited ability to delineate the details of the complex temporal bone and cochlea-vestibular anatomy and disease pathology. This can be overcome by the use of High resolution computed tomography (HRCT) evaluation of the temporal bone. HRCT is helpful in evaluating the anatomy and pathology type and extent of disease, thereby helps in preoperative planning. </span></p><p class="abstract"><strong>Methods:</strong> <span lang="EN-IN">The CT scan of forty five patients attending the outpatient department of otorhinolaryngology in a tertiary care centre between August 2014 to August 2017 was evaluated in this study. Each CT scan was interpreted by an otolaryngologist and a radiologist and interpretation was by consensus. The data collected was evaluated and results are reported as rates and proportions (%).  </span></p><p class="abstract"><strong>Results:</strong> <span lang="EN-IN">The study evaluated CT scan of 45 patients of which 35 were male patients and 10 were female patients with age ranging from 5 years to 75 years. Most of these patients belonged to the 21-30, 31-40 age groups [9 (20%) in each group]. Infections of middle ear cleft (all with cholesteatoma), fractures of the temporal bone, anomalies and tumors of the external auditory canal and middle ear were the pathologies observed in these CT scans with infection (otomastoiditis) [23 (51.1%)] being the most common pathology observed. </span></p><p class="abstract"><strong>Conclusions:</strong> <span lang="EN-IN">Pre-operative CT scan may not only help in identifying the nature, extent of infectious disease including ossicular, bony erosions; it may also identify anomalies in the temporal bone and surrounding structures. Thus, HRCT temporal bone will help the surgeon in planning effective surgical strategy, reducing morbidity during the surgery.</span></p>

scholarly journals Usefulness of High Resolution Computed Tomography scans in depicting the status of the middle ear structures

2019 ◽  
Vol 6 (2) ◽  
pp. 449
Author(s):  
Ponnam Bharath Kumar ◽  
Kiran Mai ◽  
Santosh Karpur
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Temporal Bone ◽  
Middle Ear ◽  
High Resolution Computed Tomography ◽  
Bony Labyrinth ◽  
The Status ◽  
Hrct Temporal Bone ◽  
Operative Assessment ◽  
Middle Ear Cleft

Background: Prior to surgery it is very important that the surgeon is fully aware, and he should have the clear picture as to the extent of the disease and the nature of the disease to give satisfactory surgical outcomes for the patient. HRCT (High resolution computed tomography) is one such guiding tool for the surgeon. The objective was to study usefulness of HRCT scan in attico-antral disease in depicting the status of the middle ear structures.Methods: A total of 30 patients were studied.  HRCT temporal bone was performed by using SIEMENS EMOTION 16 slice CT machine in axial plane and coronal images were reformatted. Findings of HRCT temporal bone were recorded.  Findings of mastoid exploration surgery were recorded. Report of HRCT of temporal bone was correlated with surgical findings and tabulated using percentages.Results: Surgery showed cholesteatoma in 26 (86.6%) patients. Epitympanum was involved in 29 (96.6%) patients in HRCT and 30 (100%) patients at surgery. Extension beyond middle ear cleft was seen in 4 (13.3%) patients in HRCT and 5 (16.6%) patients at surgery. Tympanic segment of facial canal was the most commonly involved, showing erosion in 10 (33.3%) patients in HRCT and 12 (40%) patients at surgery. Lateral SCC was the most commonly involved in bony labyrinth seen in 4 (13.3%) patients in both HRCT and surgery. Erosion of dural plate was seen in 6 (20%) patients in HRCT whereas 9 (30%) patients showed dural plate erosion at surgery.Conclusions: HRCT of temporal bone plays a promising role in pre-operative assessment of cholesteatoma as it depicts the extent of the disease and integrity of most of the middle ear structures.

A Rural Hospital-Based Study on Temporal Bone Pathologies by High Resolution Computed Tomography from Bangalore, Karnataka

2021 ◽  
Vol 8 (32) ◽  
pp. 2968-2973
Author(s):  
Lilly Boney ◽  
Manasa Pandith
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Temporal Bone ◽  
Middle Ear ◽  
Rural Hospital ◽  
High Resolution Computed Tomography ◽  
Histopathological Findings ◽  
Medical College ◽  
Inflammatory Conditions ◽  
Hrct Temporal Bone

BACKGROUND The tympanic cavity is susceptible to infection by viruses and bacteria through the Eustachian tube, thereby making ear pathologies and particularly middle ear inflammatory conditions a frequent reason to consult an otorhinolaryngologist. With the advent of High-Resolution Computed Tomography, diagnosis of the middle ear anatomy, pathology and its complications if any, could be made out with better precision by providing a direct visual window by providing minute structural details. The aim of the study was to assess temporal bone pathologies that could be evaluated by HRCT study of the temporal bone in a rural hospital based setup and correlate if possible with surgical/histopathological findings. METHODS The study was a retrospective study done in M.V.J Medical College and Research Hospital, Bangalore amongst 50 patients from February 2020 to January 2021 who underwent HRCT of the temporal bone and relevant statistics were drawn from these cases. After local examination, clinical evaluation and consent, CT scan was performed. Follow-up of patients was done for confirmation with operative and/or histopathological findings whenever possible. All the data obtained were recorded in a tabulated form and analysed on MS Excel. RESULTS Amongst 50 patients, infective aetiology was found to be the most common cause, of which chronic otomastoiditis was the most common, followed by chronic Cholesteatoma, otitis media, chronic mastoiditis, and otitis externa. Amongst the congenital aetiology, we had 1 case each of osteoma, facial nerve involvement, microtia and inner ear dysplasia. Amongst the traumatic cases, longitudinal type of fracture was the most common type, followed by transverse and mixed fractures with hemotympanum being the most common HRCT finding. CONCLUSIONS HRCT of the temporal bone helps in accurate assessment of infective, congenital, traumatic and neoplastic aetiologies and helps the otologist understand the disease's extent and aid in surgery. KEYWORDS High-Resolution Computed Tomography, HRCT, Temporal bone, Radiology

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