scholarly journals Assessment of the elastic properties of the ascending aorta using electrocardiographic synchronized computed tomography angiography with advanced data processing

2019 ◽  
pp. 48-54
Author(s):  
A. Yu. Skripnik ◽  
V. A. Fokin ◽  
R. R. Mironchuk ◽  
V. E. Uspenskiy ◽  
O. B. Irtyuga ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Data Processing ◽  
Elastic Properties ◽  
Computed Tomography Angiography ◽  
Aortic Distensibility ◽  
Ascending Aorta ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Additional Information

Aim. To modernize the computed tomography angiography (CTA) protocol with advanced data processing for the diagnosis of ascending aortic (AA) aneurysms, determining the aortic distensibility and compliance. Material and methods. We examined 24 patients (14 men) aged 43 to 72 years old with aneurysm or dilatation of ascending aorta (AA). CTA was performed on Siemens Somatom Definition AS and Philips Ingenuity Elite 128-slice scanners with electrocardiographic (ECG) synchronization after a bolus injection of contrast agents (100-120 ml). End-systolic and end-diastolic frames, maximum aortic diameter and cross-sectional area were determined; aortic distensibility and compliance were calculated.Results. According to AA diameter in end-diastolic frame, patients were divided into 3 groups. Group 1 — 6 patients, d< 45 mm (39 [39; 40] mm), group 2 — 7 patients, d =45-50 mm (48 [46; 49] mm) and group 3 — 11 patients, d >50 mm (51 [51; 54] mm). A correlation between aortic distensibility and compliance and such parameters as age, systolic blood pressure, systolic and was found. Correlation between the aortic compliance and diastolic diameter can be used for predicting of diameter increase rate.Conclusion. The designed CTA protocol with advanced data processing allows evaluating the AA distensibility and compliance by the diameter and cross-sectional area in patients with AA dilatation. These criteria provide additional information about the aortic elastic properties and can be used for determining the management strategy.

Nasal vestibule wall elasticity: interactions with a nasal dilator strip

1999 ◽  
Vol 86 (5) ◽  
pp. 1638-1643 ◽  
Author(s):  
T. C. Amis ◽  
J. P. Kirkness ◽  
E. di Somma ◽  
J. R. Wheatley
Keyword(s):  
Elastic Properties ◽  
Cross Sectional Area ◽  
Horizontal Direction ◽  
Sectional Area ◽  
Cross Sectional ◽  
Nasal Vestibule ◽  
Wall Displacement ◽  
Recoil Force ◽  
Wall Compliance

We studied the effect of an adhesive external nasal dilator strip (ENDS) on external nasal geometry in 20 healthy Caucasian adults (10 men, 10 women; age 21–45 yr). The recoil force exerted by ENDS was estimated by bending the device ( n = 10) with known weights. In the horizontal direction, a small/medium-sized ENDS in situ exerted a unilateral recoil force of 21.4–22.6 g. Application of ENDS resulted in a displacement of the lateral nasal vestibule walls that had both anterosuperior and horizontal components and that was maintained over an 8-h period. The resultant unilateral nasal vestibule wall displacement at the tip of the device was at 47.6 ± 2.0° to the horizontal (as related to the plane of the device when in situ) and had a magnitude of 3.5 ± 0.1 mm. ENDS increased external nasal cross-sectional area by 23.0–65.3 mm2. Nasal vestibule wall compliance was estimated at 0.05–0.16 mm/g. Thus ENDS applies a relatively constant abducting force irrespective of nasal width. Variable responsiveness to ENDS may be related to differences in elastic properties of the nasal vestibule wall.

scholarly journals A clinical prediction rule to identify difficult intubation in children with Robin sequence requiring mandibular distraction osteogenesis based on craniofacial CT measures

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Zhe Mao ◽  
Na Zhang ◽  
Yingqiu Cui
Keyword(s):  
Computed Tomography ◽  
Retrospective Study ◽  
Difficult Intubation ◽  
Prediction Rule ◽  
Clinical Prediction Rule ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Clinical Prediction ◽  
Cross Sectional ◽  
Mandibular Distraction Osteogenesis

Abstract Background Airway management is challenging in children with Robin sequence (RS) requiring mandibular distraction osteogenesis (MDO). We derived and validated a prediction rule to identify difficult intubation before MDO for children with RS based on craniofacial computed tomography (CT) images. Method This was a retrospective study of 69 children with RS requiring MDO from November 2016 to June 2018. Multiple CT imaging parameters and baseline characteristic (sex, age, gestational age, body mass index [BMI]) were compared between children with normal and difficult intubation according to Cormack−Lehane classification. A clinical prediction rule was established to identify difficult intubation using group differences in CT parameters (eleven distances, six angles, one section cross-sectional area, and three segment volumes) and clinicodemographic characteristics. Predictive accuracy was evaluated by receiver operating characteristic (ROC) curve analysis. Results The overall incidence of difficult intubation was 56.52%, and there was no significant difference in sex ratio, age, weight, height, BMI, or gestational age between groups. The distance between the root of the tongue and posterior pharyngeal wall was significantly shorter, the bilateral mandibular angle shallower, and the cross-sectional area at the epiglottis tip smaller in the difficult intubation group. A clinical prediction rule based on airway cross-sectional area at the tip of the epiglottis was established. Area > 36.97 mm2 predicted difficult intubation while area < 36.97 mm2 predicted normal intubation with 100% sensitivity, 62.5% specificity, 78.6% positive predictive value, and 100% negative predictive value (area under the ROC curve = 0.8125). Conclusion Computed tomography measures can objectively evaluate upper airway morphology in patients with RS for prediction of difficult intubation. If validated in a larger series, the measures identified could be incorporated into airway assessment tools to guide treatment decisions. This was a retrospective study and was granted permission to access and use these medical records by the ethics committee of Guangzhou Women and Children’s Medical Center. Trials registration Registration No. ChiCTR1800018252, NaZhang, Sept 7 2018.

scholarly journals A guide for using NIH Image J for single slice cross-sectional area and composition analysis of the thigh from computed tomography

PLoS ONE ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. e0211629 ◽  
Author(s):  
Douglas E. Long ◽  
Alejandro G. Villasante Tezanos ◽  
James N. Wise ◽  
Philip A. Kern ◽  
Marcas M. Bamman ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cross Sectional Area ◽  
Composition Analysis ◽  
Sectional Area ◽  
Cross Sectional ◽  
Nih Image ◽  
Single Slice

scholarly journals Stone Attenuation Value and Cross-Sectional Area on Computed Tomography Predict the Success of Shock Wave Lithotripsy

2013 ◽  
Vol 54 (7) ◽  
pp. 454 ◽  
Author(s):  
Michio Tanaka ◽  
Eisuke Yokota ◽  
Yoichiro Toyonaga ◽  
Fumitaka Shimizu ◽  
Yoshiyuki Ishii ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Shock Wave ◽  
Shock Wave Lithotripsy ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Attenuation Value

scholarly journals Nondimensional translational characteristics of elastomer components

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Andreas Dutzler ◽  
◽  
Christian Buzzi ◽  
Martin Leitner ◽  
◽  
...  
Keyword(s):  
Elastic Properties ◽  
Numerical Study ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Component Size ◽  
Rail Vehicles ◽  
Force Displacement

Elastomer components are used in both primary and secondary spring stages in bogies of rail vehicles. The design of spring components of a bogie requires knowledge of the calculation of the elastic properties of these components. An elastomer spring component is typically analyzed in the dimension to be investigated. Calculated force-displacement curves are directly related to the material and dimension of the component itself. The objective of this paper is to establish generalized or, in other words, universally valid force-displacement characteristics by breaking the entanglement with component size. The advantage of this approach is the extended validity of the results for a specific spring shape of any size. The simulations are performed only once for each shape and may be converted to any other size using the proposed methodology. A numerical study of a layer spring with rectangular cross-sectional area and fixed edges on both top and bottom sides serves as a reference example.

Sign in / Sign up

Export Citation Format

Share Document