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Coronary catheter kinking is an uncommon but potentially catastrophic complication of cardiac catheterization. Although simple maneuvers can often result in resolution of a kink, tighter knots may not respond to such measures. We provide a systematic, stepwise approach to the prevention and treatment of catheter kinking.
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OBJECTIVE: To investigate the effect of embolic protection device (EPD) use on periprocedural complications in patients with carotid artery stenosis with anatomical variations. METHOD: The study retrospectively evaluated 185 patients who consecutively underwent carotid artery stenting between November 2020 and December 2023. Forty-four patients with difficult anatomical structures, anatomical variations in the common carotid artery (CCA) and internal carotid artery (ICA) (tortuosity, kinking, or coiling), and a CCA-ICA angle of >60 degrees were included in the sample. The patients were divided into two groups according to the use of EPD filters during the procedure and compared in terms of periprocedural events. RESULTS: Of the 44 patients included in the study, 24 (54.5 %) were male, and the mean age of all patients was 68.7 ± 8.7 years. Comorbidities were present in 93.2 % (n = 41) of the patients. The most common comorbidity was hypertension (n = 32, 72.8 %). The CCA-ICA angle was ≥60 degrees in 45.4 % (n = 20) of all patients. ICA tortuosity was detected in 27.2 % (n = 12) of the patients, ICA kinking in 13.6 % (n = 6), ICA coiling in 6.8 % (n = 3), and CCA tortuosity in 6.8 % (n = 3). Procedure-related periprocedural events developed in 38.6 % (n = 17) of the patients. Postprocedural mortality occurred in two patients, secondary to myocardial infarction in one and COVID-19 pneumonia in the other. There was no significant difference between the filter and non-filter groups in relation to periprocedural events (p = 0.638). Major stroke did not occur in either group. Minor neurological events occurred in 15 % (n = 3/20) of the patients in the filter group and 16.7 % (n = 4/24) of those in the non-filter group. The incidence of vasospasm was statistically higher in patients using filters compared to those without filters (30 % vs. 0 %; P = 0.005, respectively). CONCLUSION: Evaluation of vascular anatomy before carotid artery stenting is important to decide on the technical procedure to be applied in the procedure. The use of EPD in unfavorable anatomy does not reduce periprocedural neurological events. Instead, it results in technical difficulties, prolongs the duration of procedure, and leads to arterial vasospasm. Considering the high periprocedural events in this study, carotid endarterectomy may be a better alternative to endovascular treatment in patients with unfavorable carotid artery anatomy.
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Freeze-drying is a commonly employed method in the food industry to extend shelf life of products. However, this process remains time and energy consuming. While higher shelf temperatures accelerate the process, they also pose the risk of product damage. The microstructure of the product, influencing heat and mass transport, is a critical factor. This study aims to understand the impact of 3-dimensional (3D) structural parameters (pore size, shape and orientation) on local primary freeze-drying kinetics. Freeze-drying experiments were conducted with maltodextrin solutions (c1 = 0.05, c2 = 0.15 and c3 = 0.3 w/w) at different shelf temperatures (T1 = -11, T2 = -15 and T3 = -33 °C) with the use of a freeze-drying stage that allows in-situ visualization of the process inside a 4D-X-Ray computed tomography (XCT). The findings show the importance of understanding the microstructure in detail to optimize the sublimation time during the freeze-drying process. It is shown that for longitudinal pores, the orientation is a crucial parameter.
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Liofilização , Polissacarídeos , Liofilização/métodos , Cinética , Polissacarídeos/química , Porosidade , Tomografia Computadorizada por Raios X , Temperatura , Conservação de Alimentos/métodosRESUMO
BACKGROUND: There is growing evidence supporting that vascular abnormalities contribute to multiple sclerosis (MS), and retinal microvasculature functions as a visible window to observe vessels. We hypothesized that retinal vascular curve tortuosity is associated with MS, which this study aims to address. METHODS: Participants from the UK Biobank with complete clinical records and gradable fundus photos were included in the study. Arteriolar and venular curve tortuosity and vessel area density are quantified automatically using a deep learning system. Individuals with MS were matched to healthy controls using propensity score matching (PSM). Conditional logistic regression was used to investigate the association between retinal vascular characteristics and MS. We also used a receiver operating characteristic (ROC) curve to assess the diagnostic performance of MS. RESULTS: Venular curve tortuosity (VCT) was found to be significantly associated with MS. And patients with multiple sclerosis were probable to have lower VCT than the non-MS group (OR = 0.22 [95 % CI, 0.05 to 0.92], P < 0.05). CONCLUSIONS: Our study reveals a significant association between vessel curve tortuosity and MS. The lower curve tortuosity of the retinal venular network may indicate a higher risk of incident multiple sclerosis.
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Bancos de Espécimes Biológicos , Esclerose Múltipla , Vasos Retinianos , Humanos , Esclerose Múltipla/fisiopatologia , Esclerose Múltipla/diagnóstico por imagem , Esclerose Múltipla/epidemiologia , Esclerose Múltipla/diagnóstico , Feminino , Masculino , Pessoa de Meia-Idade , Reino Unido , Vasos Retinianos/diagnóstico por imagem , Vasos Retinianos/patologia , Estudos Transversais , Adulto , Microvasos/patologia , Microvasos/diagnóstico por imagem , Microvasos/fisiopatologia , Idoso , Aprendizado Profundo , Biobanco do Reino UnidoRESUMO
BACKGROUND: Arterial tortuosity syndrome is a rare Autosomal recessive disease that leads to a loss of function of the connective tissues of the body, this happens due to a mutation in the solute carrier family 2 member 10 (SLC2A10) gene. ATS is more likely to occur in Large and medium-sized arteries including the aorta and pulmonary arteries. This syndrome causes the arteries to be elongated and tortuous, This tortuosity disturbs the blood circulation resulting in stenosis and lack of blood flow to organs and this chronic turbulent flow increases the risk of aneurysm development, dissection and ischemic events. CASE PRESENTATION: A 2 years old Arabian female child was diagnosed with ATS affecting the pulmonary arteries as a newborn, underwent a pulmonary arterial surgical reconstruction at the age of 2 years old due to the development of pulmonary artery stenosis with left pulmonary artery having a peak gradient of 73 mmHg with a peak velocity of 4.3 m/s and the right pulmonary artery having a peak gradient of 46 mmHg with a peak velocity of 3.4 m/s causing right ventricular hypertension. After surgical repair the left pulmonary artery has a peak pressure gradient of 20 mmHg, with the right pulmonary artery having a peak pressure gradient of 20 mmHg. CONCLUSION: ATS is a rare genetic condition that affects the great arteries especially the pulmonary arteries causing stenotic and tortuous vessels that may be central branches or distal peripheral branches that leads to severe right ventricular dysfunction and hypertension. We believe that surgical treatment provides the optimum outcomes when compared to transcather approaches especially when the peripheral arteries are involved. Some challenges and hiccups might occur, especially lung reperfusion injury that needs to be diagnosed and treated accordingly.
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Artéria Pulmonar , Dermatopatias Genéticas , Malformações Vasculares , Humanos , Artéria Pulmonar/cirurgia , Artéria Pulmonar/anormalidades , Feminino , Malformações Vasculares/cirurgia , Malformações Vasculares/complicações , Pré-Escolar , Dermatopatias Genéticas/cirurgia , Dermatopatias Genéticas/complicações , Dermatopatias Genéticas/genética , Procedimentos Cirúrgicos Vasculares/métodos , Estenose de Artéria Pulmonar/cirurgia , Instabilidade Articular/cirurgia , Instabilidade Articular/genética , Procedimentos de Cirurgia Plástica/métodos , Artérias/anormalidadesRESUMO
Cervicocerebral artery dissection stands out as a significant contributor to ischemic stroke in young adults. Several studies have shown that arterial tortuosity is associated with dissection. We searched Pubmed and Embase to identify studies on the association between arterial tortuosity and cervicocerebral artery dissection, and to perform a review on the epidemiology of cervicocerebral artery tortuosity and dissection, pathophysiology, measurement of vessels tortuosity, strength of association between tortuosity and dissection, clinical manifestation and management strategies. The prevalence of tortuosity in dissected cervical arteries was reported to be around 22%-65% while it is only around 8%-22% in non-dissected arteries. In tortuous cervical arteries elastin and tunica media degradation, increased wall stiffness, changes in hemodynamics as well as arterial wall inflammation might be associated with dissection. Arterial tortuosity index and vertebrobasilar artery deviation is used to measure the level of vessel tortuosity. Studies have shown an independent association between these two measurements and cervicocerebral artery dissection. Different anatomical variants of tortuosity such as loops, coils and kinks may have a different level of association with cervicocerebral artery dissection. Symptomatic patients with extracranial cervical artery dissection are often treated with anticoagulant or antiplatelet agents, while patients with intracranial arterial dissection were often treated with antiplatelets only due to concerns of developing subarachnoid hemorrhage. Patients with recurrent ischemia, compromised cerebral blood flow or contraindications for antithrombotic agents are usually treated with open surgery or endovascular technique. Those with subarachnoid hemorrhage and intracranial artery dissection are often managed with surgical intervention due to high risk of re-hemorrhage.
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Dissecação da Artéria Vertebral , Humanos , Dissecação da Artéria Vertebral/diagnóstico por imagem , Artéria Vertebral/cirurgia , Artéria Vertebral/anormalidades , Artérias/anormalidades , Instabilidade Articular , Dermatopatias Genéticas , Malformações VascularesRESUMO
Purpose: The aim of this study was to evaluate the association between computed tomography (CT) quantitative pulmonary vessel morphology and lung function, disease severity, and mortality risk in patients with chronic obstructive pulmonary disease (COPD). Patients and Methods: Participants of the prospective nationwide COSYCONET cohort study with paired inspiratory-expiratory CT were included. Fully automatic software, developed in-house, segmented arterial and venous pulmonary vessels and quantified volume and tortuosity on inspiratory and expiratory scans. The association between vessel volume normalised to lung volume and tortuosity versus lung function (forced expiratory volume in 1 sec [FEV1]), air trapping (residual volume to total lung capacity ratio [RV/TLC]), transfer factor for carbon monoxide (TLCO), disease severity in terms of Global Initiative for Chronic Obstructive Lung Disease (GOLD) group D, and mortality were analysed by linear, logistic or Cox proportional hazard regression. Results: Complete data were available from 138 patients (39% female, mean age 65 years). FEV1, RV/TLC and TLCO, all as % predicted, were significantly (p < 0.05 each) associated with expiratory vessel characteristics, predominantly venous volume and arterial tortuosity. Associations with inspiratory vessel characteristics were absent or negligible. The patterns were similar for relationships between GOLD D and mortality with vessel characteristics. Expiratory venous volume was an independent predictor of mortality, in addition to FEV1. Conclusion: By using automated software in patients with COPD, clinically relevant information on pulmonary vasculature can be extracted from expiratory CT scans (although not inspiratory scans); in particular, expiratory pulmonary venous volume predicted mortality. Trial Registration: NCT01245933.
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Pulmão , Valor Preditivo dos Testes , Artéria Pulmonar , Doença Pulmonar Obstrutiva Crônica , Índice de Gravidade de Doença , Humanos , Feminino , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/mortalidade , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Masculino , Idoso , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Volume Expiratório Forçado , Pulmão/fisiopatologia , Pulmão/diagnóstico por imagem , Pulmão/irrigação sanguínea , Artéria Pulmonar/fisiopatologia , Artéria Pulmonar/diagnóstico por imagem , Medição de Risco , Prognóstico , Veias Pulmonares/fisiopatologia , Veias Pulmonares/diagnóstico por imagem , Veias Pulmonares/anormalidades , Angiografia por Tomografia Computadorizada , Interpretação de Imagem Radiográfica Assistida por Computador , Modelos de Riscos Proporcionais , Modelos Lineares , Tomografia Computadorizada Multidetectores , Modelos Logísticos , Países BaixosRESUMO
BACKGROUND AND AIMS: Neurological abnormalities have been frequently reported in individuals with Marfan Syndrome (MFS). However, available data relies solely on retrospective studies predating current diagnostic criteria. METHODS: Cross-sectional study comprehensively investigating neurological abnormalities within a prospective cohort of adults (≥ 18 years) with genetically confirmed MFS referred to an Italian hub center for heritable connective tissue diseases (Jan. 1st - Nov. 15th, 2021). RESULTS: We included a total of 38 individuals (53% female). The commonest neurological symptom was migraine (58%), usually without aura (73%). Neuropsychological testing was generally unremarkable, whilst anxiety and depression were highly prevalent within our cohort (42% and 34%, respectively). The most frequent brain parenchymal abnormality was the presence of cortico-subcortical hypointense spots on brain MRI T2* Gradient-Echo sequences (39%), which were found only in patients with a prior history of aortic surgery. Migraineurs had a higher frequency of brain vessels tortuosity vs. individuals without migraine (73% vs. 31%; p = 0.027) and showed higher average and maximum tortuosity indexes in both anterior and posterior circulation brain vessels (all p < 0.05). At univariate regression analysis, the presence of brain vessels tortuosity was significantly associated with a higher risk of migraine (OR 5.87, CI 95% 1.42-24.11; p = 0.014). CONCLUSIONS: Our study confirms that neurological abnormalities are frequent in individuals with MFS. While migraine appears to be associated with brain vessels tortuosity, brain parenchymal abnormalities are typical of individuals with a prior history of aortic surgery. Larger prospective studies are needed to understand the relationship between parenchymal abnormalities and long-term cognitive outcomes.
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BACKGROUND: Increased arterial tortuosity has been associated with various cardiovascular complications. However, the extent and role of arterial tortuosity in non-atherosclerotic vascular diseases remain to be fully elucidated. This study aimed to assess arterial tortuosity index (ATI) in patients with non-atherosclerotic vascular diseases and the associated factors. METHODS: This is a retrospective analysis of patients with non-atherosclerotic vascular diseases referred to the Malformation and Rare Vascular Disease Center at the University Hospital in Lausanne (Switzerland). Computed tomography angiography (CTA) images performed between October 2010 and April 2022 were retrieved and the aortic tortuosity index (ATI) was calculated. Patients were classified based on diagnosis into the following groups: arterial dissection & aneurysm, arteritis & autoimmune disease, hereditary connective tissue diseases, and fibromuscular dysplasia (FMD). Univariate and multivariate logistic regression analysis was used to determine potentially relevant predictors of aortic tortuosity. RESULTS: The mean age upon computed tomography angiography (CTA) was 46.8 (standard deviation [SD] 14.6) years and 59.1% of the patients were female. Mean ATI was higher in patients over 60 years old (1.27), in those with arterial aneurysms (mean: 1.11), and in those diagnosed with hypertension (mean: 1.13). When only patients over 60 years old were considered, those diagnosed with connective tissue diseases had the highest ATI. At multivariate regression analysis, increasing age (p < 0.05), presence of arterial aneurysms (p < 0.05), and hypertension (p < 0.05) were independently associated with ATI. CONCLUSIONS: The ATI may be a promising tool in diagnostic evaluation, cardiovascular risk stratification, medical or surgical management, and prognostic assessment in several non-atherosclerotic vascular conditions. Further studies with longitudinal design and larger cohorts are needed to validate the role of ATI in the full spectrum of vascular diseases.
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Aneurisma , Angiografia por Tomografia Computadorizada , Hipertensão , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto , Hipertensão/complicações , Aneurisma/patologia , Aneurisma/diagnóstico por imagem , Doenças Vasculares/patologia , Doenças Vasculares/diagnóstico por imagem , Idoso , Artérias/patologia , Artérias/diagnóstico por imagem , Fatores EtáriosRESUMO
PURPOSE: To determine the prevalence of different extracranial internal carotid artery (EICA) variations in CT angiography (CTA) of the neck and its predisposing factors. METHODS: In this retrospective study from 2021 to 2023 conducted in the radiology department of Shafa Hospital, Kerman, Iran, all patients who had undergone neck CTA were included. Expert radiologists blindly examined each CTA image for the following: EICA variations-coiling, kinking, straight morphology, and tortuosity-and the distance between the internal carotid artery and the apex of the epiglottis and the C2 lower margin. RESULTS: Of the 106 patients, the mean age was 55.9 ± 16.9 years. 64.2% were men, and 35.8% were women. Considering each patient's bilateral anatomy, the reported 70.28% (149/212) frequency of EICA variations of all arteries. Tortuosity, kinking, and coiling variation were found in 61.8%, 4.2%, and 4.2% of arteries, respectively. Also, 54.72%, 1.89%, and 0.94% of the participants had bilateral tortuosity, kinking, and coiling, respectively. There was a significant relationship between the prevalence of EICA variations and female sex, age, and hypertension. CONCLUSION: The frequency of EICA variations in arteries and patients was 70.28% and 73.58%, respectively. Tortuosity was the most common variation. Female sex, old age, and hypertension were significant risk factors for EICA variations.
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Variação Anatômica , Artéria Carótida Interna , Angiografia por Tomografia Computadorizada , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Artéria Carótida Interna/diagnóstico por imagem , Artéria Carótida Interna/anatomia & histologia , Artéria Carótida Interna/anormalidades , Estudos Retrospectivos , Fatores de Risco , Prevalência , Adulto , Idoso , Irã (Geográfico)/epidemiologiaRESUMO
In this study, we propose a novel method for quantifying tortuosity in 3D voxelized objects. As a shape characteristic, tortuosity has been widely recognized as a valuable feature in image analysis, particularly in the field of medical imaging. Our proposed method extends the two-dimensional approach of the Slope Chain Code (SCC) which creates a one-dimensional representation of curves. The utility of 3D tortuosity ( τ 3 D ) as a shape descriptor was investigated by characterizing brain structures. The results of the τ 3 D computation on the central sulcus and the main lobes revealed significant differences between Alzheimer's disease (AD) patients and control subjects, suggesting its potential as a biomarker for AD. We found a p < 0.05 for the left central sulcus and the four brain lobes.
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Doença de Alzheimer , Encéfalo , Imageamento Tridimensional , Humanos , Imageamento Tridimensional/métodos , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/patologia , Encéfalo/diagnóstico por imagem , Feminino , Idoso , Masculino , Algoritmos , Imageamento por Ressonância Magnética/métodos , Estudos de Casos e ControlesRESUMO
Hydrogel as a solar evaporator shows great potential in freshwater production. However, hydrogels often lead to an imbalance between solar energy input and water supply management due to their excessively high saturated water content. Thus, achieving a stable water-energy-balance in hydrogel evaporators remains challenging. Here, by tortuosity engineering designed water transport channels, a seamless high-tortuosity/low-tortuosity/high-tortuosity structured hydrogel (SHLH structure hydrogel) evaporator is developed, which enables the hydrogel with customized water transport rate, leading to the controlled water supply at the evaporator interface. An excellent equilibrium between the photothermal conversion and water supply is established, and the maximum utilization of solar energy is realized, thereby achieving an excellent evaporation rate of 3.64 kg m-2 h-1 under one solar illumination. This tortuosity engineering controlled SHLH structured evaporator provides a novel strategy to attain water-energy-balance and expands new approaches for constructing hydrogel-based evaporators with tailored water transportation capacity.
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BACKGROUND: Cervical arterial tortuosity is associated with adverse outcomes in Loeys-Dietz syndrome and other heritable aortopathies. METHODS AND RESULTS: A method to assess tortuosity based on curvature of the vessel centerline in 3-dimensional space was developed. We measured cervical carotid tortuosity in 65 patients with Loeys-Dietz syndrome from baseline computed tomography angiogram/magnetic resonance angiogram and all serial images during follow-up. Relations between baseline carotid tortuosity, age, aortic root diameter, and its change over time were compared. Patients with unoperated aortic roots were assessed for clinical end point (type A aortic dissection or aortic root surgery during 4 years of follow-up). Logistic regression was performed to assess the likelihood of clinical end point according to baseline carotid tortuosity. Total absolute curvature at baseline was 11.13±5.76 and was relatively unchanged at 8 to 10 years (fold change: 0.026±0.298, P=1.00), whereas tortuosity index at baseline was 0.262±0.131, with greater variability at 8 to 10 years (fold change: 0.302±0.656, P=0.818). Baseline total absolute curvature correlated with aortic root diameter (r=0.456, P=0.004) and was independently associated with aortic events during the 4-year follow-up (adjusted odds ratio [OR], 2.64 [95% CI, 1.02-6.85]). Baseline tortuosity index correlated with age (r=0.532, P<0.001) and was not associated with events (adjusted OR, 1.88 [95% CI, 0.79-4.51]). Finally, baseline total absolute curvature had good discrimination of 4-year outcomes (area under the curve=0.724, P=0.014), which may be prognostic or predictive. CONCLUSIONS: Here we introduce cervical carotid tortuosity as a promising quantitative biomarker with validated, standardized characteristics. Specifically, we recommend the adoption of a curvature-based measure, total absolute curvature, for early detection or monitoring of disease progression in Loeys-Dietz syndrome.
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Artérias Carótidas , Angiografia por Tomografia Computadorizada , Síndrome de Loeys-Dietz , Angiografia por Ressonância Magnética , Humanos , Feminino , Masculino , Medição de Risco , Adulto , Síndrome de Loeys-Dietz/genética , Síndrome de Loeys-Dietz/complicações , Síndrome de Loeys-Dietz/diagnóstico , Síndrome de Loeys-Dietz/diagnóstico por imagem , Pessoa de Meia-Idade , Artérias Carótidas/diagnóstico por imagem , Artérias Carótidas/patologia , Fatores de Risco , Adulto Jovem , Valor Preditivo dos Testes , Dissecção Aórtica/diagnóstico por imagem , Dissecção Aórtica/diagnóstico , Dissecção Aórtica/cirurgia , Malformações Vasculares/diagnóstico por imagem , Malformações Vasculares/diagnóstico , Imageamento Tridimensional , Reprodutibilidade dos Testes , Dermatopatias Genéticas/genética , Dermatopatias Genéticas/diagnóstico por imagem , Dermatopatias Genéticas/diagnósticoRESUMO
Purpose: Iliac limb occlusion (ILO) is a serious complication of endovascular abdominal aneurysm repair (EVAR). This study aimed to identify predictive factors for ILO derived from aortoiliac morphology, endovascular procedure-related parameters, and aneurysmal remodeling characteristics. Patients and Methods: Patient demographics, pre-EVAR anatomical characteristics of the aneurysm, endovascular procedure details, and post-EVAR aneurysmal remodeling outcomes were analyzed and compared using univariate analysis. Statistically significant factors were subsequently subjected to Cox regression and Kaplan-Meier analyses. Results: Between January 2013 and April 2022, 66 patients were included in this study. Fourteen patients presented with ILO and were compared with 52 control patients with patent endograft limb over at least 1-year of follow-up. The tortuosity indices of the common iliac artery (CIA) and endograft iliac limb to vessel oversizing were significantly larger in the ILO group than in the patent endograft limb group. The CIA index of tortuosity ≥1.08, and endograft iliac limb to vessel oversizing ≥18.8% were independent predictors for ILO. During the follow-up of all patients, the proximal aortic neck and CIA diameters increased, aneurysm sac diameter decreased, and aortic neck and aortic length increased. The aortoiliac length increased over time in patients with patent endograft limb but not in patients with ILO. A change in the lowest renal artery-left iliac bifurcation distance â¦0.07 mm increased the risk of ILO. Conclusion: ILO is predisposed to occur when the CIA index of tortuosity ≥1.08 and endograft iliac limb to vessel oversizing ≥18.8% are present. Significant aortoiliac remodeling, including proximal aortic neck dilatation, neck straightening, aneurysmal sac regression, iliac artery enlargement, and aortic lengthening, occurs after EVAR. Aortoiliac elongation was observed in patients with patent endograft limb, but not in patients with ILO. ILO was associated with a change in the lowest renal artery-left iliac bifurcation from the postoperative measurements ⦠0.07 mm.
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The effect of arterial tortuosity on intracranial atherosclerosis (ICAS) is not well understood. This study aimed to evaluate the effect of global intracranial arterial tortuosity on intracranial atherosclerotic burden in patients with ischemic stroke. We included patients with acute ischemic stroke who underwent magnetic resonance angiography (MRA) and classified them into three groups according to the ICAS burden. Global tortuosity index (GTI) was defined as the standardized mean curvature of the entire intracranial arteries, measured by in-house vessel analysis software. Of the 516 patients included, 274 patients had no ICAS, 140 patients had a low ICAS burden, and 102 patients had a high ICAS burden. GTI increased with higher ICAS burden. After adjustment for age, sex, vascular risk factors, and standardized mean arterial area, GTI was independently associated with ICAS burden (adjusted odds ratio [adjusted OR] 1.33; 95% confidence interval [CI] 1.09-1.62). The degree of association increased when the arterial tortuosity was analyzed limited to the basal arteries (adjusted OR 1.48; 95% CI 1.22-1.81). We demonstrated that GTI is associated with ICAS burden in patients with ischemic stroke, suggesting a role for global arterial tortuosity in ICAS.
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Arteriosclerose Intracraniana , Angiografia por Ressonância Magnética , Humanos , Feminino , Masculino , Arteriosclerose Intracraniana/diagnóstico por imagem , Arteriosclerose Intracraniana/patologia , Arteriosclerose Intracraniana/complicações , Idoso , Pessoa de Meia-Idade , AVC Isquêmico/diagnóstico por imagem , AVC Isquêmico/patologia , Fatores de Risco , Artérias Cerebrais/diagnóstico por imagem , Artérias Cerebrais/patologia , Artérias/anormalidades , Instabilidade Articular , Dermatopatias Genéticas , Malformações VascularesRESUMO
Desert ants stand out as some of the most intriguing insect navigators, having captured the attention of scientists for decades. This includes the structure of walking trajectories during goal approach and search behaviour for the nest and familiar feeding sites. In the present study, we analysed such trajectories with regard to changes in walking direction. The directional change of the ants was quantified, i.e. an angle θ between trajectory increments of a given arclength λ was computed. This was done for different length scales λ, according to our goal of analysing desert ant path characteristics with respect to length scale. First, varying λ through more than two orders of magnitude demonstrated Brownian motion characteristics typical of the random walk component of search behaviour. Unexpectedly, this random walk component was also present in - supposedly rather linear - approach trajectories. Second, there were small but notable deviations from a uniform angle distribution that is characteristic of random walks. This was true for specific search situations, mostly close to the (virtual) goal position. And third, experience with a feeder position resulted in straighter approaches and more focused searches, which was also true for nest searches, albeit to a lesser extent. Taken together, these results both verify and extend previous studies on desert ant path characteristics. Of particular interest are the ubiquitous Brownian motion signatures and specific deviations thereof close to the goal position, indicative of unexpectedly structured search behaviour.
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Formigas , Clima Desértico , Caminhada , Animais , Formigas/fisiologia , Caminhada/fisiologia , Navegação Espacial/fisiologiaRESUMO
Desert ants stand out as some of the most intriguing insect navigators, having captured the attention of scientists for decades. This includes the structure of walking trajectories during goal approach and search behaviour for the nest and familiar feeding sites. In the present study, we analysed such trajectories with regard to changes in walking direction. The directional change of the ants was quantified, i.e. an angle θ between trajectory increments of a given arclength λ was computed. This was done for different length scales λ, according to our goal of analysing desert ant path characteristics with respect to length scale. First, varying λ through more than two orders of magnitude demonstrated Brownian motion characteristics typical of the random walk component of search behaviour. Unexpectedly, this random walk component was also present in - supposedly rather linear - approach trajectories. Second, there were small but notable deviations from a uniform angle distribution that is characteristic of random walks. This was true for specific search situations, mostly close to the (virtual) goal position. And third, experience with a feeder position resulted in straighter approaches and more focused searches, which was also true for nest searches, albeit to a lesser extent. Taken together, these results both verify and extend previous studies on desert ant path characteristics. Of particular interest are the ubiquitous Brownian motion signatures and specific deviations thereof close to the goal position, indicative of unexpectedly structured search behaviour.
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Formigas , Clima Desértico , Caminhada , Animais , Formigas/fisiologia , Caminhada/fisiologia , Navegação Espacial/fisiologiaRESUMO
OBJECTIVE: The morphology of basilar artery (BA) may affect posterior circulation blood perfusion. We aimed to investigate whether different degrees of BA tortuosity could lead to the alterations of posterior circulation perfusion. METHODS: We collected 138 subjects with different BA tortuosity scores, including 32 cases of score 0, 45 cases of score 1, 43 cases of score 2, and 18 cases of score 3. A higher score represented a higher degree of BA tortuosity. Ordered logistic regression analysis was performed to investigate the risk factors for BA tortuosity. We quantitatively measured the cerebral blood flow (CBF) in eight posterior circulation brain regions using arterial spin labeling. SPSS 25.0 was used for statistical analysis. The correlation between the CBF and BA tortuosity was corrected by the Bonferroni method. The significance level was set at 0.006 (0.05/8). RESULTS: Hypertension (HR: 2.39; 95%CI: 1.23-4.71; P = 0.01) and vertebral artery dominance (HR: 2.38; 95%CI: 1.10-4.67; P = 0.03) were risk factors for BA tortuosity. CBF in occipital gray matter (R = -0.383, P < 0.001), occipital white matter (R = -0.377, P < 0.001), temporal gray matter (R = -0.292, P = 0.001), temporal white matter (R = -0.297, P < 0.001), and cerebellum (R = -0.328, P < 0.001) were negatively correlated with BA tortuosity degree. No significant correlation was found between the BA tortuosity degree and CBF in hippocampus (R = -0.208, P = 0.014), thalamus (R = -0.001, P = 0.988) and brainstem (R = -0.204, P = 0.016). CONCLUSIONS: BA tortuosity could affect posterior circulation blood perfusion. CBF was negatively correlated with BA tortuosity degree. The morphology of BA may serve as a biomarker for posterior circulation and the severity of posterior circulation ischemia.
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The review is devoted to diagnosis and treatment of internal carotid artery tortuosity. The authors consider modern classification, epidemiology and diagnostic options using neuroimaging or ultrasound-assisted functional stress tests depending on medical history and complaints. In addition to standard Doppler ultrasound, rotational and orthostatic tests are advisable due to possible changes of local shape and hemodynamic parameters following body position changes, especially in patients with concomitant atherosclerotic stenosis. Thus, a personalized approach is especially important for treatment and diagnostics of internal carotid artery tortuosity.