Improved visualization of the chorda tympani nerve using ultra‐high-resolution computed tomography

Background Recognition of the anatomical course of the chorda tympani nerve (CTN) is important for preventing iatrogenic injuries during middle-ear surgery. Purpose This study aims to compare visualization of the CTN using two computed tomography (CT) methods: conventional high-resolution CT (C-HRCT) and ultra‐high-resolution CT (U-HRCT). Materials and methods We performed a retrospective visual assessment of 59 CTNs in normal temporal bones of 54 consecutive patients who underwent both C-HRCT and U-HRCT. After dividing CTN into three anatomical segments (posterior canaliculus, tympanic segment, and anterior canaliculus), two neuroradiologists scored the visualizations on a four-point scale. Results On C-HRCT, the visual scores of the posterior canaliculus, tympanic segment, and anterior canaliculus were 3.5 ± 0.7, 1.6 ± 0.6, and 3.1 ± 0.7, respectively. The respective values were significantly higher in all segments on U-HRCT: 3.9 ± 0.2, 2.4 ± 0.6, 3.5 ± 0.6 ( p < 0.01). Although the difference in scores between methods was greatest for the tympanic segment, the visual score on U-HRCT was lower for the tympanic segment than for the anterior and posterior segments ( p < 0.01). Conclusion Ultra‐high-resolution CT provides superior visualization of the CTN, especially the tympanic segment.

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Prevalence of radiographic semicircular canal dehiscence in very young children: an evaluation using high-resolution computed tomography of the temporal bones

Pediatric Radiology ◽

10.1007/s00247-012-2489-9 ◽

2012 ◽

Vol 42 (12) ◽

pp. 1456-1464 ◽

Cited By ~ 22

Author(s):

Mari Hagiwara ◽

Jamil A. Shaikh ◽

Yixin Fang ◽

Girish Fatterpekar ◽

Pamela C. Roehm

Keyword(s):

Computed Tomography ◽

High Resolution ◽

Young Children ◽

Semicircular Canal ◽

High Resolution Computed Tomography ◽

Very Young Children ◽

Temporal Bones ◽

Canal Dehiscence

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Hypersensitivity Pneumonitis with Normal High Resolution Computed Tomography Scans

Canadian Respiratory Journal ◽

10.1155/2001/403401 ◽

2001 ◽

Vol 8 (2) ◽

pp. 98-101 ◽

Cited By ~ 3

Author(s):

Farah J Nasser-Sharif ◽

Meyer S Balter

Keyword(s):

Computed Tomography ◽

High Resolution ◽

Lupus Erythematosus ◽

Hypersensitivity Pneumonitis ◽

Pulmonary Function Tests ◽

Open Lung Biopsy ◽

Ct Scans ◽

High Resolution Computed Tomography ◽

High Resolution Ct ◽

History Of

A case of symptomatic hypersensitivity pneumonitis with normal high resolution computed tomography (CT) scans is presented. The patient, a 32-year-old man with systemic lupus erythematosus, had a chronic, progressive history of respiratory symptoms, abnormal findings on examination and abnormal pulmonary function tests but normal high resolution CT scans of the chest. Diagnosis was made through open lung biopsy. Clinical improvement was seen on removal of the offending antigen. The literature on the utility of high resolution CT scans in hypersensitivity pneumonitis is reviewed.

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Tracheal Tube Obstruction in Mechanically Ventilated Patients Assessed by High-resolution Computed Tomography

Anesthesiology ◽

10.1097/aln.0000000000000455 ◽

2014 ◽

Vol 121 (6) ◽

pp. 1226-1235 ◽

Cited By ~ 4

Author(s):

Cristina Mietto ◽

Riccardo Pinciroli ◽

Annop Piriyapatsom ◽

John G. Thomas ◽

Lynn Bry ◽

...

Keyword(s):

Computed Tomography ◽

High Resolution ◽

Tracheal Tube ◽

Chest Ct ◽

Ct Scans ◽

Common Finding ◽

High Resolution Computed Tomography ◽

Airflow Resistance ◽

High Resolution Ct ◽

Ventilated Patients

Abstract Background: Tracheal intubation compromises mucus clearance and secretions accumulate inside the tracheal tube (TT). The aim of this study was to evaluate with a novel methodology TT luminal obstruction in critically ill patients. Methods: This was a three-phase study: (1) the authors collected 20 TTs at extubation. High-resolution computed tomography (CT) was performed to determine cross-sectional area (CSA) and mucus distribution within the TT; (2) five TTs partially filled with silicone were used to correlate high-resolution CT results and increased airflow resistance; and (3) 20 chest CT scans of intubated patients were reviewed for detection of secretions in ventilated patients’ TT. Results: Postextubation TTs showed a maximum CSA reduction of (mean ± SD) 24.9 ± 3.9% (range 3.3 to 71.2%) after a median intubation of 4.5 (interquartile range 2.5 to 6.5) days. CSA progressively decreased from oral to lung end of used TTs. The luminal volume of air was different between used and new TTs for all internal diameters (P < 0.01 for new vs. used TTs for all studied internal diameters). The relationship between pressure drop and increasing airflow rates was nonlinear and depended on minimum CSA available to ventilation. Weak correlation was found between TT occlusion and days of intubation (R2 = 0.352, P = 0.006). With standard clinical chest CT scans, 6 of 20 TTs showed measurable secretions with a CSA reduction of 24.0 ± 3.9%. Conclusions: TT luminal narrowing is a common finding and correlates with increased airflow resistance. The authors propose high-resolution CT as a novel technique to visualize and quantify secretions collected within the TT lumen.

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Is high-resolution computed tomography of the temporal bones now the “gold standard” for pre-operative evaluation of otosclerosis? Our experience in a tertiary centre

The Journal of Laryngology & Otology ◽

10.1017/s0022215116003613 ◽

2016 ◽

Vol 130 (S3) ◽

pp. S92-S92

Author(s):

Edward Noon ◽

Maira Hameed ◽

Jonathan Fishman ◽

Gitta Madani ◽

Abhijeet Parikh

Keyword(s):

Computed Tomography ◽

High Resolution ◽

Gold Standard ◽

High Resolution Computed Tomography ◽

Tertiary Centre ◽

Operative Evaluation ◽

Temporal Bones

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Anatomy of the Transarcuate Approach to the Petrous Apex

Otolaryngology ◽

10.1016/j.otohns.2008.05.516 ◽

2008 ◽

Vol 139 (2_suppl) ◽

pp. P98-P98

Author(s):

Alice D Lee ◽

Sanaz Hamidi ◽

Hamid R Djalilian

Keyword(s):

Computed Tomography ◽

High Resolution ◽

Semicircular Canal ◽

Petrous Apex ◽

Minimal Risk ◽

High Resolution Computed Tomography ◽

Superior Semicircular Canal ◽

The Mean ◽

Temporal Bones ◽

Anterior Posterior

Problem The petrous apex is considered to be one of the most difficult areas of the temporal bone to approach surgically. We present data describing the dimensions of a transarcuate approach to the petrous apex, as measured on high resolution computed tomography. Methods Measurements of the mean dimensions and ranges through the crura of the superior semicircular canal were made. The measurements were obtained from high-resolution computed tomography images of 30 temporal bones in 19 consecutively presenting patients with a pneumatized posterior petrous apex cell tract on CT. Measurements were obtained with the use of the standard PACS (picture archiving and communication system) software. Results The mean anterior-posterior space in the superior semicircular canals without transcrural pneumatization was 4.96±0.39 mm. The mean superior- inferior dimension was 4.98±0.48 mm. The same measurements in canals with pneumatized intercrural tracts were 5.17±0.51 mm and 5.11±0.62 mm respectively. The mean anterior-posterior distance and superior-inferior distance of the intercrural air tracts themselves were 2.09±0.57 and 2.01±0.45mm. There was a statistically significant difference in the anterior-posterior size between the pneumatized and non-pneumatized canals but not in the superior-inferior distance. Conclusion Pneumatized bones demonstrate a slight increase in the subarcuate dimensions as compared to non-pneumatized bones. The transarcuate approach is a viable one for drainage and biopsy of the petrous apex. Significance Our study demonstrates that the transarcuate approach is anatomically possible for drainage of the petrous apex with minimal risk to the superior semicircular canal. This would be especially useful for the drainage of cholesterol granulomas of the petrous apex or biopsy in this area.

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Evaluation of the mastoid air cell system by high resolution computed tomography: three-dimensional multiplanar volume rendering technique

The Journal of Laryngology & Otology ◽

10.1258/002221503768199906 ◽

2003 ◽

Vol 117 (8) ◽

pp. 595-598 ◽

Cited By ~ 30

Author(s):

Ahmet Koç ◽

Gazanfer Ekinci ◽

A. Mert Bilgili ◽

Ihsan N. Akpinar ◽

Hamdi Yakut ◽

...

Keyword(s):

Computed Tomography ◽

High Resolution ◽

Temporal Bone ◽

Volume Rendering ◽

Three Dimensional ◽

Cell System ◽

Mastoid Cavity ◽

High Resolution Computed Tomography ◽

Mastoid Pneumatization ◽

Temporal Bones

The mastoid air cell system is an important contributor to the pathophysiology of middle-ear inflammatory disease. The mastoid cavity is not only an air reservoir, but also an active space for gas exchange. Various methods of temporal bone imaging have been designed to investigate mastoid pneumatization. In this study, we examined 100 normal temporal bones for the evaluation of mastoid pneumatization. Mastoid air cell systems were measured by reconstructed axial and coronal high resolution computed tomography (HRCT) images. The reconstructions were made by a three-dimensional multiplanar volume rendering (3D MPVR) technique. The mean volume of the mastoid air cell pneumatization was 7.9 cm3 (4.0-14.0 cm3, SD = 2.3 cm3). The ears were allocated to the groups with respect to measured mastoid air cell pneumatization. Twenty-eight per cent of the ears have small pneumatization with an aircell system not exceeding 6 cm3. Fifty-two per cent had an air cell system between six and 10 cm3, and 20 per cent had an air cell system exceeding 10 cm3. With its excellent imaging quality and the ability to eliminate bone and soft tissue, HRCT is the best method for evaluating the mastoid air cell system. The 3D MPVR technique must be used tomeasure the temporal bone/mastoid pneumatization for the best results.

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The Crista Fenestra and Its Impact on the Surgical Approach to the Scala Tympani during Cochlear Implantation

Audiology and Neurotology ◽

10.1159/000471840 ◽

2017 ◽

Vol 22 (1) ◽

pp. 50-55 ◽

Cited By ~ 4

Author(s):

Roberto D. Angeli ◽

Joel Lavinsky ◽

Enio T. Setogutti ◽

Luiz Lavinsky

Keyword(s):

High Resolution ◽

Cochlear Implantation ◽

Round Window ◽

Ct Scanning ◽

Round Window Membrane ◽

Scala Tympani ◽

High Resolution Computed Tomography ◽

High Resolution Ct ◽

Round Window Niche ◽

Temporal Bones

Objective: The aim of this work was to describe the dimensions of the crista fenestra and determine its presence by means of high-resolution computed tomography (CT) for the purpose of cochlear implantation via the round window approach. Methods: A series of 10 adult human temporal bones underwent high-resolution CT scanning and were further dissected for microscopic study of the round window niche. Results: In all of the specimens, the round window membrane was fully visualized after the complete removal of bony overhangs. The crista fenestra was identified as a sharp bony crest located in the anterior and inferior borders of the niche; its area ranged from 0.28 to 0.80 mm2 (mean 0.51 ± 0.18). The proportion of the area occupied by the crista fenestra in the whole circumference of the round window ranged from 23 to 50% (mean 36%). We found a moderate positive correlation between the area of the niche and the dimensions of the crista fenestra (Spearman rho: 0.491). In every case, high-resolution CT scanning was unable to determine the presence of the crista fenestra. Conclusion: The crista fenestra occupies a variable but expressive area within the bony round window niche. Narrower round window niches tended to house smaller crests. The presence of the crista fenestra is an important obstacle to adequate access to the scala tympani. Nevertheless, a high-resolution CT scan provides no additional preoperative information with regard to its presence for the purpose of surgical access to the scala tympani via the round window niche.

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Accuracy of High-Resolution Computed Tomography Chest in Diagnosing Pulmonary Tuberculosis by taking AFB culture findings as Gold Standard

10.53350/pjmhs211561429 ◽

2021 ◽

Vol 15 (6) ◽

pp. 1429-1430

Author(s):

M. Amin ◽

M. Javed ◽

A. Noreen ◽

M. Mehboob ◽

N. Pasha ◽

...

Keyword(s):

Computed Tomography ◽

High Resolution ◽

Pulmonary Tuberculosis ◽

Gold Standard ◽

Imaging Modality ◽

Sufficient Accuracy ◽

Male Population ◽

High Resolution Computed Tomography ◽

Pulmonary Tb ◽

High Resolution Ct

Aim: To determine the accuracy of high resolution CT Chest (HRCT) for diagnosis of pulmonary tuberculosis (PTB) by taking AFB culture findings as gold standard. Methods: This validation study was conducted in patients referred for HRCT Chest for diagnosis of pulmonary tuberculosis in OPD/ Radiology unit of CH & ICH within duration of 6 months from September-2020 to February -2021. Patients with suspicion of PTB were included. In all patients, sputum samples were obtained and the AFB test was performed for diagnosis of PTB. After that high resolution CT Chest (HRCT) was performed for diagnosis of PTB. Results: Mean age was 54.67 ± 12.36 years. Male population 54% and female was 46%. AFB culture results for pulmonary. TB was positive in 44 patients and was negative in 56 patients. HRCT findings were positive for pulmonary TB in 46 patients and were negative in 54 patients (Table 1). The sensitivity of HRCT was 81.8%, specificity of HRCT was 82.1%, PPV was 78.3% and NPV was 85.2% (Table 2). Conclusion: HRCT Chest has a sufficient accuracy for PTB diagnosis taking AFB culture results as gold standard. So HRCT Chest can be opted as imaging modality of choice in patients having mixed plain radiographs findings. This will aid in early identification and starting treatment of PTB. Keywords: Accuracy, high resolution computed tomography, pulmonary tuberculosis.

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Volumetric characteristics of idiopathic pulmonary fibrosis lungs: computational analyses of high-resolution computed tomography images of lung lobes

Respiratory Research ◽

10.1186/s12931-019-1189-5 ◽

2019 ◽

Vol 20 (1) ◽

Cited By ~ 1

Author(s):

Bora Sul ◽

Lucia Flors ◽

Joanne Cassani ◽

Michael J. Morris ◽

Jaques Reifman ◽

...

Keyword(s):

Computed Tomography ◽

High Resolution ◽

Idiopathic Pulmonary Fibrosis ◽

Pulmonary Fibrosis ◽

Lung Volume ◽

High Resolution Computed Tomography ◽

Healthy Group ◽

Volumetric Characteristics ◽

The Difference ◽

Lung Lobes

Abstract Background Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease involving progressive degeneration of lung capacity. Current diagnosis of IPF heavily relies on visual evaluation of fibrotic features in high-resolution computed tomography (HRCT) images of the lungs. Although the characteristics of this disease have been studied at the molecular and cellular levels, little is known about the mechanical characteristics of IPF lungs inferred from HRCT images. To this end, we performed a pilot study to investigate the radiographic and volumetric characteristics of lungs in subjects with IPF. Methods We collected HRCT images of healthy (N = 13) and IPF (N = 9) lungs acquired at breath-holds after full inspiration (expanded state) and full expiration (contracted state). We performed statistical analyses on Hounsfield unit (HU) histograms, lobar volumes (V: lobe volume normalized by the lung volume), and lobar flows (Q: the difference in lobe volume divided by the difference in lung volume between the expanded and contracted states). Results Parameters characterizing the HU histograms (i.e., mean, median, skewness, and kurtosis) significantly differed between healthy and IPF subjects, for all lobes in both expanded and contracted states. The distribution of V across lobes differed significantly between the groups in both states. The distribution of Q also differed significantly between the groups: Q values of the lower lobes for the IPF group were 33% (right) and 22% (left) smaller than those for the healthy group, consistent with the observation that radiographic scores were highest in the lower lung section in IPF. Notably, the root-mean-squared difference (RMSD) of Q, a measure of distance from the mean value of the healthy group, clearly distinguished the IPF subjects (RMSD of Q > 1.59) from the healthy group (RMSD of Q < 0.67). Conclusion This study shows that lung volume and flow distribution change heterogeneously across the lung lobes of IPF subjects, with reduced capacity in the lower lobes. These volumetric changes may improve our understanding of the pathophysiology in IPF lungs.

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