scholarly journals Airflow Simulation inside the Nasal Cavity

2020 ◽  
Vol 4 (1) ◽  
pp. 21-25
Author(s):  
Milad Ahmadi ◽  
Mohammad Zuber ◽  
S.M. Abdul Khader
Keyword(s):  
Computed Tomography ◽  
Laminar Flow ◽  
Nasal Cavity ◽  
Ct Scans ◽  
Comsol Multiphysics ◽  
Particulate Matters ◽  
Flow Rates ◽  
Healthy Female ◽  
The Individual ◽  
Human Nose

Filtration of particulate matters in the human nose depends on the Individual aspects of the nasal cavity such as the geometry and flow rate collectively. To better understand the physiology of the nose, a 3D computational model of a human nasal cavity was developed based on the computed tomography (CT) scans of a healthy female. COMSOL Multiphysics was used to analyze the velocity patterns for laminar flow rates of 7.5L/min and 15L/min and the differences were explored and analyzed.

Influence of airflow dynamics on vortices in the human nasal cavity

2019 ◽  
Vol 36 (9) ◽  
pp. 3164-3179
Author(s):  
Punjan Dohare ◽  
Amol P. Bhondekar ◽  
Anupma Sharma ◽  
C. Ghanshyam
Keyword(s):  
Numerical Simulations ◽  
Nasal Cavity ◽  
Three Dimensional ◽  
Nasal Airflow ◽  
Nasal Valve ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Flow Rates ◽  
Content Type ◽  
Human Nose

Purpose The purpose of this paper is to understand the effect of airflow dynamics on vortices for different flow rates using the human nose three-dimensional model. Design/methodology/approach Olfaction originates with air particles travelling from an external environment to the upper segment of the human nose. This phenomenon is generally understood by using the nasal airflow dynamics, which enhances the olfaction by creating the vortices in the human nose. An anatomical three-dimensional model of the human nasal cavity from computed tomography (CT) scan images using the MIMICS software (Materialise, USA) was developed in this study. Grid independence test was performed through volume flow rate, pressure drop from nostrils and septum and average velocity near the nasal valve region using a four computational mesh model. Computational fluid dynamics (CFD) was used to examine the flow pattern and influence of airflow dynamics on vortices in the nasal cavity. Numerical simulations were conducted for the flow rates of 7.5, 10, 15 and 20 L/min using numerical finite volume methods. Findings At coronal cross-sections, dissimilar nasal airflow patterns were observed for 7.5, 10, 15 and 20 L/min rate of fluid flow in the human nasal cavity. Vortices that are found at the boundaries with minimum velocity creates deceleration zone in the nose vestibule region, which is accompanied by flow segregation. Maximum vortices were observed in the nasal valve region and the posterior end of the turbinate region, which involves mixing and recirculation and is responsible for enhancing the smelling process. Practical implications The proposed analysis is applicable to design the sensor chamber for electronic noses. Originality/value In this paper, the influence of airflow dynamics on vortices in the human nasal cavity is discussed through numerical simulations.

Turbinate atrophy evaluation in pigs by computed tomography

2003 ◽  
Vol 51 (4) ◽  
pp. 485-491 ◽  
Author(s):  
T. Magyar ◽  
F. Kovács ◽  
T. Donkó ◽  
H. Bíró ◽  
R. Romvári ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Nasal Cavity ◽  
Scoring System ◽  
Ct Images ◽  
Area Ratio ◽  
Ct Scans ◽  
Non Invasive ◽  
Visual Scoring ◽  
Ratio Determination ◽  
Visualisation Technique

Computed tomography (CT), a non-invasive visualisation technique was applied for imaging the bony structures of the nasal cavity of pigs, and compared to the traditional scoring system of turbinate atrophy in swine. Twenty-three 27-week-old pigs representing various stages of turbinate atrophy were used. Nasal structures were visually scored on CT scans and transversal cuts of the noses at the level of the first upper premolar teeth using the same scoring system in both cases. A tissue/air area ratio was also determined based on density differences. A highly significant correlation was found between visual scoring of CT images and transversal cuts of pig noses (r = 0.98, p < 0.0001) as well as between visual scoring of CT images and tissue/air area ratio determination (r = -0.82, p < 0.0001).

Xenon-Enhanced Computed Tomography Quantifies Normal Maxillary Sinus Ventilation

2000 ◽  
Vol 122 (3) ◽  
pp. 422-424 ◽  
Author(s):  
Donald Leopold ◽  
S. James Zinreich ◽  
Brett A. Simon ◽  
Michelle M. Cullen ◽  
Catherine Marcucci
Keyword(s):  
Computed Tomography ◽  
Nasal Cavity ◽  
Maxillary Sinus ◽  
Healthy Subjects ◽  
Ct Scans ◽  
Xenon Ct ◽  
Time Constants ◽  
Representative Data ◽  
Enhanced Ct ◽  
Enhanced Computed Tomography

OBJECTIVE: The purpose of this study was to determine the applicability, safety, and normal parameters of a xenon-enhanced CT technique to quantify maxillary sinus ventilation. PATIENTS AND METHODS: Nine healthy subjects inhaled a xenon-oxygen-air mixture through their noses while repeated CT scans were performed through the same section of their sinuses. Images were obtained every 1 to 3 minutes and analyzed to measure the density of the gas in the maxillary sinus as a function of time. RESULTS: Individual nasal cavity time constants ranged from 0.5 to 18 minutes. Studies performed after decongestion showed poorer sinus ventilation. CONCLUSIONS: The xenon-CT washin/washout technique is safe, effective, and gives representative data.

Evaluation of inferior turbinate outfracture outcomes using computed tomography

2013 ◽  
Vol 51 (3) ◽  
pp. 275-279
Author(s):  
J.Y. Min ◽  
H.J. Dhong ◽  
H.J. Cho ◽  
S.K. Chung ◽  
H.Y. Kim
Keyword(s):  
Computed Tomography ◽  
Nasal Cavity ◽  
Pituitary Adenomas ◽  
Attachment Site ◽  
Inferior Turbinate ◽  
Lateral Wall ◽  
Original Position ◽  
Ct Scans ◽  
Endonasal Approach ◽  
Nasal Floor

Background: Outfracture of the inferior turbinate (IT) presents numerous advantages, but it is generally believed that the lateralized IT will resume its original position. The purpose of this study was to evaluate the outcome of IT outfracture objectively using computed tomography (CT). Methodology: Fifteen patients who underwent bilateral IT outfracture for the removal of pituitary adenomas by the endonasal approach were enrolled. The angles between the lateral wall of the nasal cavity (NC) and IT on both sides were measured from CT scans before and at least 6 months after operation. In addition, we evaluated the effects of variables including age, thickness of IT attachment site and width of the nasal floor, on the angles. Results: Regardless of the side where a Hardy retractor was placed, the angle between the lateral wall of the NC and IT decreased significantly within 6 months after the outfracture compared to preoperative values on both sides. Other variables showed no significant correlations with the angle between the IT and the lateral wall of the NC. Conclusion: The outfracture procedure effectively lateralized the IT and it maintained that position for at least 6 months after the operation.

In situ identification of Action 4, SECA and QD-PEP bullets from special police ammunitions by computed tomography

2020 ◽  
Vol 60 (3) ◽  
pp. 188-195 ◽  
Author(s):  
Dominic Gascho ◽  
Niklaus Zoelch ◽  
Eva Deininger-Czermak ◽  
Carlo Tappero ◽  
Henning Richter ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Gunshot Wounds ◽  
The Body ◽  
Ct Scans ◽  
Ct Scanner ◽  
Non Invasive ◽  
Clear Identification ◽  
Magnetic Resonance Imaging Mri ◽  
The Individual

Introduction Special deformation bullets were developed for police forces to achieve a defined penetration depth (avoiding over-penetration) and a controlled energy transfer (avoiding collateral damage). This article focuses on Action 4, SECA and QD-PEP bullets. These 9 mm bullets were specially designed for controlled deformation. The characteristic slight mushrooming with a front cross-section of approximately 11.5 mm after entering a ballistic simulant was verified in ballistic tests. To achieve such slight mushrooming, the projectile’s core is hollowed. The purpose of this study was to investigate the feasibility of visualising the hollowed cores of Action 4, SECA and QD-PEP bullets using a standard clinical computed tomography (CT) scanner for non-invasive identification of these special bullets from police ammunitions. Methods First, undeformed specimens were scanned to reveal the shape of the hollowed core of each type of special bullet. Second, Action 4, SECA and QD-PEP bullets were fired towards animal cadaver models to visualise their hollow core after deformation inside biological tissue. Third, two reviewers were tasked with identifying special bullets from police ammunition (Action 4 bullets: n = 3) among 10 CT examinations of humans with lodged projectiles who were selected by the supervisor of the study. Results The CT scans of the undeformed specimens revealed the special design of the bullets’ metal core. All special bullets from police ammunitions that were fired towards an animal cadaver model demonstrated the characteristic slight mushrooming. In accordance with the CT scans of the undeformed bullets, visualisation of the individual internal cavities of the special bullets allowed the Action 4, SECA and QD-PEP bullets to be clearly distinguished. With regard to the real forensic cases, both reviewers clearly identified each of the three Action 4 bullets among all other lodged projectiles. Conclusions This study demonstrates the feasibility of identifying Action 4, SECA and QD-PEP bullets from special police ammunitions by CT. The individual shapes of the cavity inside the bullets were clearly visible on CT. In situ identification of these bullets can aid in the assessment of injuries, and since these bullets are fabricated from non-ferromagnetic metals, their clear identification allows for magnetic resonance imaging (MRI) without the risk of bullet movement inside the body due to the magnetic pull of the MRI unit. Furthermore, this approach could be of great interest to forensic investigators if patients who received gunshot wounds underwent non-operative treatments and the projectile remains in the body. Since the use of CT is also increasing for medico-legal post-mortem examinations, the identification of lodged projectiles is of interest for a virtual autopsy or ‘Virtopsy’.

Xenon-enhanced computed tomography quantifies normal maxillary sinus ventilation

2000 ◽  
Vol 122 (3) ◽  
pp. 422-424
Author(s):  
Donald Leopold ◽  
S. James Zinreich ◽  
Brett A. Simon ◽  
Michelle M. Cullen ◽  
Catherine Marcucci
Keyword(s):  
Computed Tomography ◽  
Nasal Cavity ◽  
Maxillary Sinus ◽  
Healthy Subjects ◽  
Ct Scans ◽  
Xenon Ct ◽  
Time Constants ◽  
Representative Data ◽  
Enhanced Ct ◽  
Enhanced Computed Tomography

OBJECTIVE The purpose of this study was to determine the applicability, safety, and normal parameters of a xenon-enhanced CT technique to quantify maxillary sinus ventilation. PATIENTS AND METHODS Nine healthy subjects inhaled a xenon-oxygen-air mixture through their noses while repeated CT scans were performed through the same section of their sinuses. Images were obtained every 1 to 3 minutes and analyzed to measure the density of the gas in the maxillary sinus as a function of time. RESULTS Individual nasal cavity time constants ranged from 0.5 to 18 minutes. Studies performed after decongestion showed poorer sinus ventilation. CONCLUSIONS The xenon-CT washin/washout technique is safe, effective, and gives representative data.

SPECIFIC CHARACTERISTICS OF BONE STRUCTURES ON CT-SCANS OF PATIENTS WITH SINONASAL INVERTED PAPILLOMAS

2019 ◽  
Vol 65 (4) ◽  
pp. 590-595
Author(s):  
Arkadiy Naumenko ◽  
Kseniya Sapova ◽  
Oleg Konoplev ◽  
Svetlana Astashchenko ◽  
Igor Chernushevich
Keyword(s):  
Computed Tomography ◽  
Tumor Recurrence ◽  
Inverted Papilloma ◽  
Ct Scans ◽  
Precise Localization ◽  
Sinonasal Inverted Papilloma ◽  
Bone Structures ◽  
Inverted Papillomas

Precise localization and excision of the originating site of a sinonasal inverted papilloma is essential for decreasing tumor recurrence. In this study we evaluated the use of preoperative computed tomography (CT) to pinpoint the attachment/origi-nating sites of the tumor.

scholarly journals Metacarpal Bony Dimensions Related to Headless Compression Screw Sizes

2019 ◽  
Vol 12 (S 01) ◽  
pp. S39-S44
Author(s):  
Michael Okoli ◽  
Kevin Lutsky ◽  
Michael Rivlin ◽  
Brian Katt ◽  
Pedro Beredjiklian
Keyword(s):  
Computed Tomography ◽  
Fracture Fixation ◽  
Ct Scans ◽  
Compression Screw ◽  
Metacarpal Head ◽  
Headless Compression Screw ◽  
Metacarpal Bones ◽  
Headless Compression Screws ◽  
The Mean ◽  
Distal Aspect

Abstract Introduction The purpose of this study is to determine the radiographic dimensions of the finger metacarpals and to compare these measurements with headless compression screws commonly used for fracture fixation. Materials and Methods We analyzed computed tomography (CT) scans of the index, long, ring, and small metacarpal bones and measured the metacarpal length, distance from the isthmus to the metacarpal head, and intramedullary diameter of the isthmus. Metacarpals with previous fractures or hardware were excluded. We compared these dimensions with the size of several commercially available headless screws used for intramedullary fixation. Results A total of 223 metacarpals from 57 patients were analyzed. The index metacarpal was the longest, averaging 67.6 mm in length. The mean distance from the most distal aspect of the metacarpal head to the isthmus was 40.3, 39.5, 34.4, and 31 mm for the index, long, ring, and small metacarpals, respectively. The narrowest diameter of the isthmus was a mean of 2.6, 2.7, 2.3, and 3 mm for the index, long, ring, and small metacarpals, respectively. Of 33 commercially available screws, only 27% percent reached the isthmus of the index metacarpal followed by 42, 48, and 58% in the long, ring, and small metacarpals, respectively. Conclusion The index and long metacarpals are at a particular risk of screw mismatch given their relatively long lengths and narrow isthmus diameters.

scholarly journals Conditional CT Strategy—An Effective Tool to Reduce Negative Appendectomy Rate and the Overuse of the CT

2021 ◽  
Vol 10 (11) ◽  
pp. 2456
Author(s):  
Raminta Luksaite-Lukste ◽  
Ruta Kliokyte ◽  
Arturas Samuilis ◽  
Eugenijus Jasiunas ◽  
Martynas Luksta ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Acute Appendicitis ◽  
Sensitivity And Specificity ◽  
Surgical Outcomes ◽  
Imaging Modality ◽  
Ct Scans ◽  
Negative Appendectomy ◽  
Transabdominal Ultrasound ◽  
First Choice ◽  
Negative Appendectomy Rate

(1) Background: Diagnosis of acute appendicitis (AA) remains challenging; either computed tomography (CT) is universally used or negative appendectomy rates of up to 30% are reported. Transabdominal ultrasound (TUS) as the first-choice imaging modality might be useful in adult patients to reduce the need for CT scans while maintaining low negative appendectomy (NA) rates. The aim of this study was to report the results of the conditional CT strategy for the diagnosis of acute appendicitis. (2) Methods: All patients suspected of acute appendicitis were prospectively registered from 1 January 2016 to 31 December 2018. Data on their clinical, radiological and surgical outcomes are presented. (3) Results: A total of 1855 patients were enrolled in our study: 1206 (65.0%) were women, 649 (35.0%) were men, and the median age was 34 years (IQR, 24.5–51). TUS was performed in 1851 (99.8%) patients, and CT in 463 (25.0%) patients. Appendices were not visualized on TUS in 1320 patients (71.3%). Furthermore, 172 (37.1%) of 463 CTs were diagnosed with AA, 42 (9.1%) CTs revealed alternative emergency diagnosis and 249 (53.8%) CTs were normal. Overall, 519 (28.0%) patients were diagnosed with AA: 464 appendectomies and 27 diagnostic laparoscopies were performed. The NA rate was 4.2%. The sensitivity and specificity for TUS and CT are as follows: 71.4% and 96.2%; 93.8% and 93.6%. (4) Conclusion: A conditional CT strategy is effective in reducing NA rates and avoids unnecessary CT in a large proportion of patients. Observation and repeated TUS might be useful in unclear cases.

scholarly journals Imaging diagnosis of classical and new pneumoconiosis: predominant reticular HRCT pattern

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Akira Masanori
Keyword(s):  
Computed Tomography ◽  
Interstitial Lung Disease ◽  
Imaging Features ◽  
Imaging Findings ◽  
Imaging Diagnosis ◽  
High Resolution Computed Tomography ◽  
Pleural Fibrosis ◽  
Pathologic Findings ◽  
Characteristic Imaging ◽  
The Individual

AbstractOur understanding of the manifestations of pneumoconioses is evolving in recent years. Associations between novel exposures and diffuse interstitial lung disease have been newly recognized. In advanced asbestosis, two types of fibrosis are seen, probably related to dose of exposure, existence of pleural fibrosis, and the host factor status of the individual. In pneumoconiosis of predominant reticular type, nodular opacities are often seen in the early phase. The nodular pattern is centrilobular, although some in metal lung show perilymphatic distribution, mimicking sarcoidosis. High-resolution computed tomography enables a more comprehensive correlation between the pathologic findings and clinically relevant imaging findings. The clinician must understand the spectrum of characteristic imaging features related to both known dust exposures and to historically recent new dust exposures.

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