Aneurysm presence at the anterior communicating artery bifurcation is associated with caliber tapering of the A1 segment

2021 ◽  
pp. 1-11
Author(s):  
Alexandra Lauric ◽  
Luke Silveira ◽  
Emal Lesha ◽  
Jeffrey M. Breton ◽  
Adel M. Malek
Keyword(s):  
Three Dimensional ◽  
Parametric Models ◽  
Anterior Communicating Artery ◽  
Predisposing Factor ◽  
Cross Sectional ◽  
Flow Acceleration ◽  
Significant Difference ◽  
Healthy Control ◽  
Mca Aneurysm

OBJECTIVE Vessel tapering results in blood flow acceleration at downstream bifurcations (firehose nozzle effect), induces hemodynamics predisposing to aneurysm initiation, and has been associated with middle cerebral artery (MCA) aneurysm presence and rupture status. The authors sought to determine if vessel caliber tapering is a generalizable predisposing factor by evaluating upstream A1 segment profiles in association with aneurysm presence in the anterior communicating artery (ACoA) complex, the most prevalent cerebral aneurysm location associated with a high rupture risk. METHODS Three-dimensional rotational angiographic studies were analyzed for 68 patients with ACoA aneurysms, 37 nonaneurysmal contralaterals, and 53 healthy bilateral controls (211 samples total). A1 segments were determined to be dominant, codominant, or nondominant based on flow and size. Equidistant cross-sectional orthogonal cuts were generated along the A1 centerline, and cross-sectional area (CSA) was evaluated proximally and distally, using intensity-invariant edge detection filtering. The relative tapering of the A1 segment was evaluated as the tapering ratio (distal/proximal CSA). Computational fluid dynamics was simulated on ACoA parametric models with and without tapering. RESULTS Aneurysms occurred predominantly on dominant (79%) and codominant (17%) A1 segments. A1 segments leading to unruptured ACoA aneurysms had significantly greater tapering compared to nonaneurysmal contralaterals (0.69 ± 0.13 vs 0.80 ± 0.17, p = 0.001) and healthy controls (0.69 ± 0.13 vs 0.83 ± 0.16, p < 0.001), regardless of dominance labeling. There was no statistically significant difference in tapering values between contralateral A1 and healthy A1 controls (0.80 ± 0.17 vs 0.83 ± 0.16, p = 0.56). Hemodynamically, A1 segment tapering induces high focal pressure, high wall shear stress, and high velocity at the ACoA bifurcation. CONCLUSIONS Aneurysmal, but not contralateral or healthy control, A1 segments demonstrated significant progressive vascular tapering, which is associated with aneurysmogenic hemodynamic conditions at the ACoA complex. Demonstration of the upstream tapering effect in the communicating ACoA segment is consistent with its prior detection in the noncommunicating MCA bifurcation, which together form more than 50% of intracranial aneurysms. The mechanistic characterization of this upstream vascular tapering phenomenon is warranted to understand its clinical relevance and devise potential therapeutic strategies.

Low Level of Serum Sclerostin in Adult Patients with Tumor-induced Osteomalacia Comparing with X-linked Hypophosphatemia

2021 ◽  
Author(s):  
Xiaolin Ni ◽  
Qi Zhang ◽  
Xiang Li ◽  
Qianqian Pang ◽  
Yiyi Gong ◽  
...  
Keyword(s):  
Bone Mass ◽  
Cross Sectional Study ◽  
Healthy Controls ◽  
Cross Sectional ◽  
Significant Difference ◽  
Healthy Control ◽  
Premenopausal Patients ◽  
Male Patients ◽  
Sclerostin Level ◽  
Sclerostin Antibody

Abstract Context Sclerostin is an inhibitor of Wnt-β-catenin signaling to regulate bone formation. Circulating sclerostin levels were reported to be elevated in patients with X-linked hypophosphatemia (XLH), and sclerostin antibody (Scl-Ab) has been shown to increase bone mass and normalize circulating phosphate levels in Hyp mice. However, circulating sclerostin level in acquired hypophosphatemic patients with tumor-induced osteomalacia (TIO) remains rare reported. Objectives This study was designed to evaluate serum sclerostin levels in TIO patients comparing them with age-, sex- matched healthy controls and XLH patients, and analyze correlation of circulating sclerostin with BMD and laboratory parameters. Design, Setting and Participants 190 individuals including 83 adult TIO patients, 83 adult healthy controls and 24 adult XLH patients were enrolled in this cross-sectional study. Main outcome measures Serum sclerostin levels were determined in TIO patients, healthy controls and XLH patients. Results TIO patients (43 male and 40 female) aged 44.3 ± 8.7 (mean ± SD) years had lower levels of circulating sclerostin than healthy controls (94.2 ± 45.8 vs 108.4 ± 42.3 pg/mL, p = 0.01) with adjustment for age, gender, BMI and diabetes rate. Sclerostin levels were positively associated with age (r = 0.238, p = 0.030). Male patients had higher sclerostin level than female patients (104.7 ± 47.3 vs 83.0 ± 41.8 pg/mL, p = 0.014) and postmenopausal patients had higher tendency of sclerostin level than premenopausal patients (98.4 ± 48.8 vs 71.6 ± 32.3 ng/ml, p = 0.05). Sclerostin levels were positively associated with BMD of L1-4 (r = 0.255, p = 0.028), femoral neck (r = 0.242, p = 0.039) and serum calcium (r = 0.231, p = 0.043). TIO subgroup patients (n=24, 35.9 ± 7.3 years old) comparing with age-, sex-matched adult XLH patients and healthy controls revealed significant difference of sclerostin levels (XLH, TIO and healthy control were 132.0 ± 68.8, 68.4 ± 31.3 and 98.6 ± 41.1 pg/mL, respectively, p &lt; 0.001). Conclusions Circulating sclerostin levels were decreased in TIO patients but increased in XLH patients, which might be result of histological abnormality and bone mass.

Age-Dependent Three-Dimensional Evaluation of the Spheno-Occipital Synchondrosis Using Computed Tomography

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Arezoo Jahanbin ◽  
Shirin Dokht Shirazi ◽  
Elaheh Kamyabnezhad ◽  
Neda Eslami ◽  
Seyed Hosein Hoseini Zarch
Keyword(s):  
Developmental Stage ◽  
Three Dimensional ◽  
Cross Sectional ◽  
Old Patients ◽  
Significant Difference ◽  
Growth Center ◽  
Different Populations ◽  
Males And Females ◽  
Ossification Process ◽  
Age And Sex

Background: The spheno‐occipital synchondrosis (SOS) is an important growth center which plays an important role in cranial base development and can define the final relation of SOS with the upper and lower jaws. The morphology and fusion degree of SOS varies in different ages among different populations. Objectives: Thus, the aim of this study was to evaluate the age and sex dependence of ossification of the spheno-occipital synchondrosis in the Iranian population using CBCT. Methods: This cross-sectional retrospective study was performed on 517 CBCT images of 6- to 18-year-old patients in Mashhad, Iran. Patients with obvious pathology or fractures were excluded from the study. The SOS ossification was classified into four stages from 0 to 3. Two independent observers scored the images. The ossification stage of the SOS was classified according to the age and sex of the patients. Kruskal-Wallis and Kendall’s tau-b used for statistical analysis. Results: In this study, 517 samples of 260 females (50.3%) and 257 males (49.7%) with a mean age of 12.03 ± 3.74 years were examined. A significant difference did not exist between males and females regarding their stage of SOS ossification, although males were younger at the SOS transitional stages of 0 to 1, and 1 to 2 compared to females. Also, the SOS starts the ossification process at the age of 11 in females and 10.8 in males. Conclusions: The present study showed in the mean age of 16.81 ± 1.12 years, most subjects were in developmental stage 3. Due to the fact that in developmental stage 3 SOS closes, there were no passive maxillary growth after this time. In none of the SOS stages, females and males differed significantly in mean age (P > 0.05). The age of the onset of SOS closure in females was 11 years and in males it was about 10.8 years.

Reference range of fetal myocardial area by three-dimensional ultrasonography and its applicability in fetuses of pre-gestational diabetic women

2019 ◽  
Vol 47 (4) ◽  
pp. 422-428 ◽  
Author(s):  
José Francisco Melo Júnior ◽  
Nathalie Jeanne Bravo-valenzuela ◽  
Luciano Marcondes Machado Nardozza ◽  
Alberto Borges Peixoto ◽  
Rosiane Mattar ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Goodness Of Fit ◽  
Reference Range ◽  
Polynomial Regression ◽  
Three Dimensional ◽  
Image Correlation ◽  
Coefficient Of Determination ◽  
Cross Sectional ◽  
Myocardial Area ◽  
Significant Difference

Abstract Objective To determine the reference range for the myocardial area in healthy fetuses using three-dimensional (3D) ultrasonography and validate these results in fetuses of pregnant women with pre-gestational diabetes mellitus (DM). Methods This cross-sectional retrospective study included 168 healthy pregnant women between gestational weeks 20 and 33+6 days. The myocardial area was measured using spatio-temporal image correlation (STIC) in the four-chamber view. Polynomial regression models were used, and the goodness of fit of the models were evaluated by the coefficient of determination (R2). Intra- and inter-observer reproducibility was determined using the concordance correlation coefficient (CCC). Validation was performed in 30 pregnant women with pre-gestational DM. Results There was a strong correlation (R2=0.71, P<0.0001) between myocardial area and gestational age. There was good intra- and inter-observer reproducibility, with a CCC of 0.86 and 0.83, respectively. However, there was no significant difference in the mean myocardial area between healthy fetuses and fetuses of women with pre-gestational DM (0.11 cm2, P=0.55). Conclusion The reference range was determined for the myocardial area in fetuses, and there was no significant difference in this variable between healthy fetuses and the fetuses of women with pre-gestational DM.

A bioartificial rat heart tissue: Perfusion decellularization and characterization

2019 ◽  
Vol 42 (12) ◽  
pp. 757-764 ◽  
Author(s):  
Busra Ozlu ◽  
Mert Ergin ◽  
Sevcan Budak ◽  
Selcuk Tunali ◽  
Nuh Yildirim ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Three Dimensional ◽  
Tissue Perfusion ◽  
Heart Tissue ◽  
Cell Nuclei ◽  
Tissue Sections ◽  
The Past ◽  
Significant Difference ◽  
Structural Preservation

Despite remarkable advancement in the past decades, heart-related defects are still prone to progress irreversibly and can eventually lead to heart failure. A personalized extracellular matrix–based bioartificial heart created by allografts/xenografts emerges as an alternative as it can retain the original three-dimensional architecture combined with a preserved natural heart extracellular matrix. This study aimed at developing a procedure for decellularizing heart tissue harvested from rats and evaluating decellularization efficiency in terms of residual nuclear content and structural properties. Tissue sections showed no or little visible cell nuclei in decellularized heart, whereas the native heart showed dense cellularity. In addition, there was no significant variation in the alignment of muscle fibers upon decellularization. Furthermore, no significant difference was detected between native and decellularized hearts in terms of fiber diameter. Our findings demonstrate that fiber alignment and diameter can serve as additional parameters in the characterization of biological heart scaffolds as these provide valuable input for evaluating structural preservation of decellularized heart. The bioartificial scaffold formed here can be functionalized with patient’s own material and utilized in regenerative engineering.

Three-Dimensional Anatomic Characterization of the Canine Laryngeal Abductor and Adductor Musculature

2000 ◽  
Vol 109 (5) ◽  
pp. 505-513 ◽  
Author(s):  
Corey W. Mineck ◽  
Roger Chan ◽  
Niro Tayama ◽  
Ingo R. Titze
Keyword(s):  
Vocal Fold ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Cross Sectional ◽  
3 Dimensional ◽  
Moment Arms ◽  
Intrinsic Laryngeal Muscle ◽  
Posterior Cricoarytenoid ◽  
Intrinsic Laryngeal Muscles

The biomechanics of vocal fold abduction and adduction during phonation, respiration, and airway protection are not completely understood. Specifically, the rotational and translational forces on the arytenoid cartilages that result from intrinsic laryngeal muscle contraction have not been fully described. Anatomic data on the lines of action and moment arms for the intrinsic laryngeal muscles are also lacking. This study was conducted to quantify the 3-dimensional orientations and the relative cross-sectional areas of the intrinsic abductor and adductor musculature of the canine larynx. Eight canine larynges were used to evaluate the 3 muscles primarily responsible for vocal fold abduction and adduction: the posterior cricoarytenoid, the lateral cricoarytenoid, and the interarytenoid muscles. Each muscle was exposed and divided into discrete fiber bundles whose coordinate positions were digitized in 3-dimensional space. The mass, length, relative cross-sectional area, and angle of orientation for each muscle bundle were obtained to allow for the calculations of average lines of action and moment arms for each muscle. This mapping of the canine laryngeal abductor and adductor musculature provides important anatomic data for use in laryngeal biomechanical modeling. These data may also be useful in surgical procedures such as arytenoid adduction.

Effect of Cross Aspect Ratio on Flow in Diverging and Converging Microchannels

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
V. S. Duryodhan ◽  
Shiv Govind Singh ◽  
Amit Agrawal
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Aspect Ratio ◽  
Numerical Study ◽  
Three Dimensional ◽  
Hydraulic Diameter ◽  
Working Fluid ◽  
Cross Sectional ◽  
Flow Acceleration ◽  
Three Dimensional Models

Aspect ratio is an important parameter in the study of flow through noncircular microchannel. In this work, three-dimensional numerical study is carried out to understand the effect of cross aspect ratio (height to width) on flow in diverging and converging microchannels. Three-dimensional models of the diverging and converging microchannels with angle: 2–14 deg, aspect ratio: 0.05–0.58, and Reynolds number: 130–280 are employed in the simulations with water as the working fluid. The effects of aspect ratio on pressure drop in equivalent diverging and converging microchannels are studied in detail and correlated to the underlying flow regime. It is observed that for a given Reynolds number and angle, the pressure drop decreases asymptotically with aspect ratio for both the diverging and converging microchannels. At small aspect ratio and small Reynolds number, the pressure drop remains invariant of angle in both the diverging and converging microchannels; the concept of equivalent hydraulic diameter can be applied to these situations. Onset of flow separation in diverging passage and flow acceleration in converging passage is found to be a strong function of aspect ratio, which has not been shown earlier. The existence of a critical angle with relevance to the concept of equivalent hydraulic diameter is identified and its variation with Reynolds number is discussed. Finally, the effect of aspect ratio on fluidic diodicity is discussed which will be helpful in the design of valveless micropump. These results help in extending the conventional formulae made for uniform cross-sectional channel to that for the diverging and converging microchannels.

scholarly journals Comparison of ox-LDL Levels in Diabetic Patients with Normo-, Micro-, and Macroalbuminuria with Their First Degree Relatives and the Healthy Control Group

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Parisa Behzadi ◽  
Firouzeh Torabi ◽  
Massoud Amini ◽  
Ashraf Aminorroaya
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Cross Sectional Study ◽  
Control Group ◽  
Diabetic Patients ◽  
Cross Sectional ◽  
First Degree Relatives ◽  
Significant Difference ◽  
Healthy Control ◽  
And Control

Oxidized low density lipoprotein (ox-LDL) is a product of oxidative stress. In this cross-sectional study, we compared the ox-LDL concentrations in diabetic patients with normoalbuminuria (n=28), microalbuminuria (n=28), and macroalbuminuria (n=28) with their first degree relatives (n=28) and healthy control people (n=31). They were selected by consecutive patient selection method. The ox-LDL level was assayed using ELISA. We measured blood pressure, lipid profile, fasting plasma glucose (FPG), and HbA1c in all groups. There was no significant difference in ox-LDL concentrations among normoalbuminuric, microalbuminuric, and macroalbuminuric diabetic groups. In diabetic patients with micro- and macroalbuminuria, ox-LDL concentration was higher than their first degree relatives (P=0.04andP=0.03) and control group (P=0.001andP=0.03, resp.). In normoalbuminuric diabetic persons, ox-LDL concentration was just higher than that of healthy people (P=0.02). There was no statistically significant difference in ox-LDL levels between normoalbuminuric diabetic patients and their first degree relatives. In conclusion, the presence and progression of albuminuria in diabetic patients are not related to ox-LDL concentration and genetic predisposition influences the plasma OX-LDL level. Larger sample size is needed to confirm this conclusion in future studies.

scholarly journals Three-dimensional volumetric evaluation of the different mandibular segments using CBCT in patients affected by juvenile idiopathic arthritis: a cross-sectional study

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Davide Cavagnetto ◽  
Andrea Abate ◽  
Alberto Caprioglio ◽  
Paolo Cressoni ◽  
Cinzia Maspero
Keyword(s):  
Juvenile Idiopathic Arthritis ◽  
Three Dimensional ◽  
Pairwise Comparison ◽  
Cross Sectional Study ◽  
Control Group ◽  
Case Group ◽  
Unaffected Side ◽  
Cross Sectional ◽  
Affected Side ◽  
Significant Difference

Abstract Background There is currently no information on how different mandibular segments are affected by juvenile idiopathic arthritis. The aim of this paper is to assess volumetric differences of different mandibular segments in subjects with unilateral and bilateral JIA and to compare them with non-JIA control volumes. Materials and methods Forty subjects with unilateral TMJ involvement and 48 with bilateral TMJ involvement were selected for the case group and 45 subjects with no known rheumatic comorbidities for the control group. The mandible of each subject was divided according to a validated method into different paired volumes (hemimandible, condyle, ramus and hemibody). Results The ANOVA test revealed a statistically significant difference in all the groups for condylar and ramus volumes, and the pairwise comparison evidenced a statistically significant higher condylar and ramus volume in the control group (1444.47 mm3; 5715.44 mm3) than in the affected side in the unilateral JIA group (929.46 mm3; 4776.31 mm3) and the bilateral JIA group (1068.54 mm3; 5715.44 mm3). Moreover, there was also a higher condylar volume in the unaffected side in the unilateral JIA group (1419.39 mm3; 5566.24 mm3) than in the bilateral JIA group and the affected side in the unilateral JIA group. Conclusions The affected side of unilateral JIA patients showed statistically significant lower volumes in the hemimandible, in the condyle and in the ramus. The largest total mandibular volume was observed in the control group, followed by the unilateral JIA group and, lastly, by the bilateral JIA group.

scholarly journals Damage Mechanics of Carbon Nanotubes

2020 ◽  
Vol 03 (02) ◽  
pp. 1-1
Author(s):  
George Z. Voyiadjis ◽  
◽  
Peter I. Kattan ◽  
Keyword(s):  
Carbon Nanotubes ◽  
Damage Mechanics ◽  
Three Dimensional ◽  
Damage Variable ◽  
Dimensional Case ◽  
Third Order ◽  
Cross Sectional ◽  
Energy Equivalence ◽  
The One

A robust mathematical method for the characterization of damage in carbon nanotubes is presented the presentation here is limited to elasticity. In this regard, the second and third order elastic stiffnesses are employed. All this is based on damage mechanics. The hypotheses of elastic strain equivalence and elastic energy equivalence are utilized. A new damage variable is proposed that is defined in terms of the surface area. This is in contrast to the classical damage variable which is defined in terms of the cross-sectional area. In the presentation, both the one-dimensional case (scalars) and the three-dimensional case (tensors) are illustrated.

Plexus-specific retinal capillary avascular area in exudative age-related macular degeneration with projection-resolved OCT angiography

2020 ◽  
pp. bjophthalmol-2020-317562
Author(s):  
Liqin Gao ◽  
Jie Wang ◽  
Qisheng You ◽  
Yukun Guo ◽  
Christina J Flaxel ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Three Dimensional ◽  
Age Related Macular Degeneration ◽  
Retinal Layer ◽  
Cross Sectional ◽  
Avascular Area ◽  
Age Related ◽  
Significant Difference ◽  
Retinal Capillary ◽  
Capillary Plexus

ObjectiveTo detect the plexus-specific retinal capillary avascular area in exudative age-related macular degeneration (EAMD) with projection-resolved optical coherence tomography angiography (PR-OCTA).Methods and analysisIn this prospective cross-sectional single centre study, eyes with treatment-naïve EAMD underwent macular 3×3 mm OCTA with AngioVue system. OCTA scans were analysed and processed including three-dimensional projection artefact removal, retinal layer semi-automated segmentation and en face angiogram generation. Automated quantification of extrafoveal (excluding the central 1 mm circle) avascular area (EAA) were calculated on projection-resolved superficial vascular complex (SVC), intermediate capillary plexus (ICP) and deep capillary plexus (DCP), respectively.ResultsNineteen eyes with EAMD and 19 age-matched healthy control eyes were included. There was no significant difference between the EAMD and control eyes in terms of age, sex, axial length and mean ocular perfusion pressure (all p>0.05). Compared with control eyes, EAMD eyes had significantly larger EAA in SVC (median 0.125 vs 0.059 mm2, p=0.006), ICP (0.016 vs 0.000 mm2, p=0.004) and DCP (0.033 vs 0.000 mm2, p＜0.001).ConclusionPR-OCTA showed that EAMD is associated with focal avascular area in all the three retinal vascular plexuses.

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