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Gotowa bibliografia na temat „Abdominal aortic calcification (AAC)”

Autor: Grafiati

Data publikacji: 23 maja 2025

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Artykuły w czasopismach na temat "Abdominal aortic calcification (AAC)"

Sanchis, Pilar, Rosmeri Rivera, Regina Fortuny, Carlos Río, Miguel Mas-Gelabert, Marta Gonzalez-Freire, Felix Grases i Luis Masmiquel. "Role of Advanced Glycation End Products on Aortic Calcification in Patients with Type 2 Diabetes Mellitus". Journal of Clinical Medicine 9, nr 6 (5.06.2020): 1751. http://dx.doi.org/10.3390/jcm9061751.

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The aim of this study was to evaluate the relationship between serum levels of advanced glycation end products (AGEs) and abdominal aortic calcification (AAC) in patients with type 2 diabetes mellitus (DM2). This was a prospective cross-sectional study. One-hundred and four consecutive patients with DM2 were given lateral lumbar X-rays in order to quantify abdominal aortic calcification (AAC). Circulating levels of AGEs and classical cardiovascular risk factors were determined. Clinical history was also registered. Patients with higher AGEs values had higher grades of aortic calcification and higher numbers of diabetic-related complications. Multivariate logistic regression analysis showed that being older, male and having high levels of AGEs and triglycerides were the independent risk factors associated to moderate-severe AAC when compared to no-mild AAC. Our results suggest that AGEs plays a role in the pathogenesis of aortic calcifications. In addition, the measurement of AGEs levels may be useful for assessing the severity of AAC in the setting of diabetic complications.

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Wu, Chung-Kuan, Che-Yu Chiang i Jun-Wei Hsieh. "Calculation of Aortic Arch Calcification Degree in Hemodialysis Patients Using Deep Learning". International Journal of Applied Sciences & Development 3 (8.10.2024): 171–75. http://dx.doi.org/10.37394/232029.2024.3.17.

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Abdominal Aortic Calcification (AAC) is a common form of vascular calcification closely associated with atherosclerosis and serves as an important marker for measuring increased risk of cardiovascular, cerebrovascular, and peripheral vascular diseases. Particularly in patients with Chronic Kidney Disease (CKD) and those undergoing dialysis, the risk of AAC significantly increases due to a combination of traditional and non-traditional risk factors. Therefore, developing a rapid and accurate method to assess the extent of AAC is crucial for preventing the progression of vascular calcification and the associated risk of cardiovascular diseases. Dialysis patients are required to undergo an abdominal X-ray annually, and the degree of calcification of the abdominal aorta is assessed manually through these X-ray images. However, these methods have limitations in identifying subtle calcifications in the abdominal aorta and the assessment process is time-consuming and depends on the experience and subjective judgment of physicians. To overcome these limitations, we propose a new method that incorporates deep learning technology to improve the accuracy of assessing the extent of AAC. Our method utilizes CNN models and attention modules to enhance the model's ability to recognize features of abdominal aortic calcification.

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Cai, Hong, Renhua Lu, Mingfang Zhang, Huihua Pang, Mingli Zhu, Weiming Zhang, Zhaohui Ni, Jiaqi Qian i Yucheng Yan. "Serum Soluble Klotho Level Is Associated with Abdominal Aortic Calcification in Patients on Maintenance Hemodialysis". Blood Purification 40, nr 2 (2015): 120–26. http://dx.doi.org/10.1159/000381937.

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Background: Klotho is a single transmembrane protein originally identified as an ‘aging suppressor'. Emerging evidence reveals that soluble Klotho (sKl) in the circulation plays important roles in anti-aging, anti-oxidation, anti-apoptosis and Wnt signaling. However, the role of serum sKl in the vascular calcification in hemodialysis patients is not clear. The aim of this study was to determine the associations of sKl with abdominal aortic calcification in patients on maintenance hemodialysis (MHD). Methods: 129 MHD patients were enrolled prospectively. Serum sKl level was detected by ELISA. Abdominal aortic calcification was measured by abdomen lateral plain radiograph, and the abdominal aorta calcification (AAC) score was calculated. The sKl levels were observed in patients with different degrees of calcification. Logistic regression analysis was used to determine the risk factor of abdominal aortic calcification in MHD patients. The diagnostic value of sKl for abdominal aortic calcification was assessed using receiver operator characteristic (ROC). Results: Abdominal aortic calcification was seen in 87 of 129 patients. The median AAC score was 4.0 (0.00, 11.00) and the median sKl level was 616.29 (378.19, 821.61) pg/ml. Serum sKl levels were inversely associated with AAC. When evaluated as AAC categories (<5, 5-15, >15) with ordinal logistic regression, each SD higher sKl was associated with 37.1% lower odds of AAC severity (proportional odds ratio: 0.629; 95% confidence interval: 0.413-0.959, p = 0.031) in models adjusted for demographic data, lifestyle factors, traditional CVD risk factors and uremic risk factors. Multivariate logistic regression analysis showed that serum sKl levels and smoking were independent risk factors for severe AAC. The area under the receiver-operating characteristic curve (AUC) of serum sKl for severe abdominal aortic calcification was 0.746 (0.612-0.880, p = 0.001), sensitivity was 0.885, and specificity was 0.562 for a cutoff value of 265.39 pg/ml. Conclusions: Lower serum sKl levels are independently associated with severe AAC. Serum sKl might have a diagnostic value for the severe AAC in MHD patients.

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Dilawar, Mubashir, Omer Sabir, Muhammad Bilal Basit, Adnan Hussain Shahid, Andleeb Kanwal i Syed Ahtesham Ali Shah. "Abdominal Aortic Calcifications in Patients with Chronic Kidney Disease: A Single Center Study in Lahore, Pakistan". Life and Science 5, nr 3 (15.08.2024): 06. http://dx.doi.org/10.37185/lns.1.1.517.

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Objective: To determine the prevalence of abdominal aortic calcification in patients diagnosed with chronickidney disease stage III to V.Study Design: Cross-sectional study.Place and Duration of Study: The study was carried out at the Department of Nephrology, Fatima MemorialHospital Lahore, Pakistan from December 2022 to December 2023.Methods: A total of 295 patients diagnosed with chronic kidney disease stages III to V were included. The lateral view of the lumbar radiograph was carried out in the standing position. All the X-rays were confidentiallysubmitted to the Central Radiology Department where a consultant Radiologist interpreted the X-ray in thelight of the Abdominal Aortic Calcification Score. Significant Abdominal Aortic Calcification (AAC) wasdesignated as per the Operation ACC score interpreted and reported by the consultant Radiologist. Chronickidney disease (CKD) and Aortic Calcification were designated.Results: Abdominal aortic calcification was found in 89 (30.17%) patients. Male gender was significantlyassociated with the presence of abdominal aortic calcification (χ2 = 50.019, df = 1, P-value 0.001).Conclusion: We concluded that there is a moderately high frequency (30%) of abdominal aortic calcification inpatients with chronic kidney disease.

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Diao, Yu-Hang, Jian Chen, Yang Liu, Dong Peng i Dong Yang. "Does aortic calcification really affect anastomotic leakage after rectal cancer surgery?" Medicine 103, nr 28 (12.07.2024): e38860. http://dx.doi.org/10.1097/md.0000000000038860.

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The purpose of the current study was to analyze whether aortic calcification had impact on the anastomotic leakage (AL) after rectal cancer (RC) surgery. We collected patients’ information from January 2011 to January 2020 in a single teaching hospital. Preoperative computed tomography images were obtained. Abdominal aortic calcification (AAC), superior mesenteric aortic calcification, and inferior mesenteric aortic calcification were recorded. The difference of AL and grade C AL was calculated. A total of 2412 RC patients were included in this study. Ninety-seven (4.0%) RC patients experienced AL and 47 (1.9%) RC patients experienced grade C AL. The amount of AAC, superior mesenteric aortic calcification, and inferior mesenteric aortic calcification was 1546 (64.1%), 128 (5.3%), and 31 (1.3%). The AL group had higher portion of AAC (P = .019) than the no AL group, and the grade C AL group had higher portion of AAC (P = .016) than the no grade C AL group. In univariate logistic regression analysis, AAC was a significant potential factor for AL (P = .021, OR = 1.739, 95% CI = 1.088–2.779) and grade C AL (P = .019, OR = 2.339, 95% CI = 1.115–4.986). However, in multivariate logistic regression, AAC was not an independent predictive factor for AL (P = .157, OR = 1.443, 95% CI = 0.871–2.358) or grade C AL (P = .064, OR = 2.055, 95% CI = 0.960–4.399). AAC was associated with higher amount of AL and grade C AL, however, AAC was not an independent predictive factor for AL or grade C AL.

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Rositawati, Wiwik, Syakib Bakri, Gatot Susilo Lawrence i Andi Wijaya. "Role of 8-isoprostane, Matrix Gla Protein (MGP) and Bone Morphogenetic Protein-2 (BMP-2) in Vascular Calcification in Chronic Kidney Disease". Indonesian Biomedical Journal 5, nr 2 (1.08.2013): 129. http://dx.doi.org/10.18585/inabj.v5i2.71.

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BACKGROUND: Vascular calcification may be an important risk factor of cardiovascular disease in Chronic Kidney Disease (CKD). The pathobiology of vascular calcification in CKD is complex and involves some factors including inflammation, oxidative stress and balancing of calcification regulators. The aim of the study was to investigate the interaction between 8-isoprostane with calcification regulators such as matrix gla protein (MGP) and bone morphogenetic protein (BMP)-2 with vascular calciication in CKD.METHODS: A cross-sectional study was performed on 63 subjects undergoing haemodialysis maintenance for more than 3 months. Abdominal aortic calcification (AAC) was measured using a lateral abdominal X-ray for calcification in abdominal aorta, which is related to severity of calcific deposits at lumbar vertebral segment (L)1-L4. Serum levels of 8-isoprostane, MGP and BMP-2 were measured by enzyme-linked immunosorbent assay method.RESULTS: Results showed that 8-isoprostane levels were correlated with BMP-2 (r=0.266, p=0.018) and MGP levels (r=0.410, p≤0.001). MGP/BMP-2 levels ratio was correlated with AAC score (r=0.279, p=0.013). Subjects were then stratified into 3 groups based on AAC score: 0, 1-6 and ≥7. The highest mean of MGP levels was in AAC score 1-6 group, and the highest mean of 8-isoprostane levels was in AAC score ≥7. In the group of AAC score 0, 8-isoprostane levels were correlated with MGP levels (r=0.499, p=0.001) and MGP/BMP-2 levels ratio (r=0.291, p=0.034). In AAC score 1-6 group, 8-isoprostane levels were correlated with BMP-2 (r=0.661, p=0.005) and MGP levels (r=0.569, p=0.017). In AAC score ≥7 group, MGP levels were positively correlated with AAC score (r=0.608, p=0.041). With multivariate logistic regression analyses, we identified that increased MGP/BMP-2 levels ratio (OR=12.436; 95% CI=1.595-96.971) was an independent predictor in aortic calcification event.CONCLUSION: We concluded that regulators of calcification including calcification inhibitor and promoter related to oxidative stress, were associated with vascular calcification in CKD. MGP levels were increased in the early of calcification and MGP/BMP-2 levels ratio was a strong predictor for vascular calcification in CKD.KEYWORDS: vascular calcification, CKD, oxidative stress, 8-isoprostane, MGP, BMP-2

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Jansson, Hanna, Aso Saeed, Maria K. Svensson, Kristina Finnved, Mikael Hellström i Gregor Guron. "Impact of Abdominal Aortic Calcification on Central Haemodynamics and Decline of Glomerular Filtration Rate in Patients with Chronic Kidney Disease Stages 3 and 4". Kidney and Blood Pressure Research 44, nr 5 (2019): 950–60. http://dx.doi.org/10.1159/000501687.

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Background/Aim: Calcifications of large arteries are frequent in chronic kidney disease (CKD) and may contribute to the high cardiovascular risk in this population. The aim of this study was to examine whether abdominal aortic calcification volume (AACV) was a predictor of the rate of decline in glomerular filtration rate (GFR) in a cohort of patients with CKD stages 3 and 4. Methods: Eighty-four patients with CKD stages 3 and 4 were enrolled in this prospective observational study. At study entry, and annually, GFR was measured by plasma 51Cr-EDTA clearance. At baseline, haemodynamics was assessed and AACV was determined by computer tomography. Results: The mean follow-up time was 3.4 years and mean decline in GFR was –2.69 mL/min/1.73 m2 per year. At baseline, abdominal aortic calcification (AAC) was detected in 66 patients (79%). A binary logistic regression analysis revealed that age was the only statistically significant independent predictor of AAC. In patients with AAC, male gender (B = 0.413, p = 0.030), aortic diastolic blood pressure (B = –0.025, p = 0.001) and ankle-brachial index (B = –1.666, p = 0.002) were independently associated with AACV using a multiple linear regression analysis. Neither the presence nor the extent of AAC was significantly associated with the rate of change in GFR during follow-up. Conclusion: In this cohort of patients with CKD stages 3 and 4, only age was an independent predictor of the presence of AAC. AACV was not associated with the rate of decline in GFR.

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Horbal, Steven, Aleda Leis, Sven Holcombe i Carrie Karvonen-Gutierrez. "EFFECT MODIFICATION OF AGE AND SEX BETWEEN AORTIC CALCIFICATION AND MORTALITY IN A COMMUNITY SAMPLE OF OLDER PATIENTS". Innovation in Aging 8, Supplement_1 (grudzień 2024): 133. https://doi.org/10.1093/geroni/igae098.0429.

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Abstract Abdominal aortic calcification (AAC) is a useful cardiovascular risk assessor in opportunistic screening. As cardiovascular risk changes with increasing age, effective AAC use depends on understanding influential factors on AAC and mortality. This study evaluated modification of age and sex on the relationship between aortic calcification and mortality. This sample includes 6647 Michigan Medicine patients age ≥ 65 years, without cardiovascular disease, and who received an abdominal computed tomography scan between 1999-2022. AAC was elevated if calcification exceeded 19.26% of the aortic wall at the L3 vertebral level. Cox regression was used to assess AAC and mortality (adjusted for body mass index and Charlson Comorbidity Index) and stratified by age group (65-79, 80+ years) and sex. In the sample, 18.3% (n=1219) were 80+ years and the mortality rate was 38.0%. Those with elevated AAC had 99% higher mortality hazard than those with unelevated AAC [HR 1.99 (95% CI 1.66, 2.41)]. A statistically significant interaction was observed between age category, sex, and AAC status. Among patients 80+ years, elevated AAC was protective for mortality [HR 0.79 (95% CI 0.62, 0.98)]. Further, elevated AAC was associated with 35% lower mortality hazard in females age 80+ [HR 0.65 (95% CI 0.46, 0.92)] but was not significant in males age 80+. Important effect modification by age and sex exists on the relationship between AAC and mortality. This suggests the impact of AAC as a risk factor for mortality may decrease with age and be less important in 80+ year old females relative to males.

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Brahmbhatt, Saloni, Mageda Mikhail, Shahidul Islam i John F. Aloia. "Vitamin D and Abdominal Aortic Calcification in Older African American Women, the PODA Clinical Trial". Nutrients 12, nr 3 (24.03.2020): 861. http://dx.doi.org/10.3390/nu12030861.

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Abdominal aortic calcification (AAC) detected on lateral vertebral fracture assessment is associated with increased cardiovascular risk. Vitamin D deficiency and toxicity have been linked with vascular calcification. The objective of this study was to determine the effect of high-dose vitamin D on the progression of AAC. The Physical Performance, Osteoporosis and vitamin D in African American Women (PODA) is a randomized, clinical trial examining the effect of vitamin D. There were 14.7% subjects with AAC in the vitamin D group, compared to 12.1% in the placebo group at baseline. The prevalence of extended AAC at baseline was 6.4% in the vitamin D group and 3.5% in the placebo group. The extended calcification scores over time were not different between groups. There was no association between AAC and serum 25(OH)D. However, PTH was associated with an increase in AAC in the placebo group.

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Chen, Wei, Ruth Eisenberg, Wenzhu B. Mowrey, Judith Wylie-Rosett, Matthew K. Abramowitz, David A. Bushinsky i Michal L. Melamed. "Association between dietary zinc intake and abdominal aortic calcification in US adults". Nephrology Dialysis Transplantation 35, nr 7 (11.07.2019): 1171–78. http://dx.doi.org/10.1093/ndt/gfz134.

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Abstract Background In animal studies, zinc supplementation inhibited phosphate-induced arterial calcification. We tested the hypothesis that higher intake of dietary zinc was associated with lower abdominal aortic calcification (AAC) among adults in the USA. We also explored the associations of AAC with supplemental zinc intake, total zinc intake and serum zinc level. Methods We performed cross-sectional analyses of 2535 participants from the National Health and Nutrition Examination Survey 2013–14. Dietary and supplemental zinc intakes were obtained from two 24-h dietary recall interviews. Total zinc intake was the sum of dietary and supplemental zinc. AAC was measured using dual-energy X-ray absorptiometry in adults ≥40 years of age and quantified using the Kauppila score system. AAC scores were categorized into three groups: no AAC (AAC = 0, reference group), mild–moderate (AAC >0–≤6) and severe AAC (AAC >6). Results Dietary zinc intake (mean ± SE) was 10.5 ± 0.1 mg/day; 28% had AAC (20% mild–moderate and 8% severe), 17% had diabetes mellitus and 51% had hypertension. Higher intake of dietary zinc was associated with lower odds of having severe AAC. Per 1 mg/day higher intake of dietary zinc, the odds of having severe AAC were 8% lower [adjusted odds ratio 0.92 (95% confidence interval 0.86–0.98), P = 0.01] compared with those without AAC, after adjusting for demographics, comorbidities and laboratory measurements. Supplemental zinc intake, total zinc intake and serum zinc level were not associated with AAC. Conclusions Higher intake of dietary zinc was independently associated with lower odds of having severe AAC among noninstitutionalized US adults.

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Rozprawy doktorskie na temat "Abdominal aortic calcification (AAC)"

Saleem, Afsah. "Machine learning for computer-aided diagnostics from complex medical images". Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2025. https://ro.ecu.edu.au/theses/2927.

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Machine learning has significantly transformed medical image analysis in the current age of artificial intelligence offering vast potential in improving disease diagnosis and management. Cardiovascular diseases (CVDs) are among the leading cause of global mortality, emphasizing the need for early detection for effective intervention and prevention. Abdominal Aortic Calcification (AAC) is an early indicator and contributor to Atherosclerotic Cardiovascular Diseases (ASCVDs) and is commonly assessed through imaging modalities such as computed tomography (CT), X-rays, and Dual-energy X-ray Absorptiometry (DXA). Among these, lateral spine DXA scans, commonly used for osteoporosis screening, offer a cost-effective and low-radiation opportunity for opportunistic CVD risk assessment. Despite advancements in medical imaging technologies, AAC evaluation still relies on manual interpretation by trained clinicians, a process that is labor-intensive, subjective, and prone to variability. Automating the process of AAC quantification can address these challenges and enable consistent, early screening for CVD risk. This research presents robust machine-learning frameworks for the automated and accurate prediction of the AAC-24 score and its classification into relevant risk classes (low, moderate, and high). First, we explore deep feature ensembling methods to develop a deep feature fusion network for AAC-4 scoring using regression loss. However, its performance was limited by class ambiguities from inter-class similarities, intra-class variations, and low resolution VFA DXA artifacts. To mitigate this problem, we formulate AAC-24 scoring as an ordinal regression problem and propose a novel supervised contrastive ordinal learning (SCOL) framework. SCOL leverages a label-dependent distance metric to capture the ordinal nature of AAC labels. Using SCOL, we develop a Dual-encoder Contrastive Ordinal Learning (DCOL) framework to learn contrastive ordinal representation at global and local levels, improving feature separability and class diversity in the latent space among the AAC-24 categories. Clinical validation demonstrated a strong association between ML-AAC-24 scores and ASCVD risk, with substantial agreement between ML predictions and expert assessments. To enhance generalizability across different imaging modalities, SCOL framework is further explored for lateral spine X-rays via cross-domain fine-tuning, enhancing its utility in diverse clinical settings. To strengthen this work on highly imbalanced disease grading medical datasets, a prototype-based learning approach is incorporated within the SCOL framework to develop a generic disease grading system. The framework is evaluated on public datasets for diabetic retinopathy grading and breast cancer staging, demonstrating its ability to learn robust, ordinal-aware prototypes that generalize across diverse medical imaging tasks. Additionally, to enhance the interpretability and reliability of automated systems in clinical diagnosis, we develop a context-aware ordinal learning framework for granular-level AAC-24 scoring. We address the challenges of SCOl in handling class imbalance for ordinal regression tasks and introduce SCOL+. We explore SCOL+ in a multi-label setting to determine the extent of calcification in each section of the aorta to aid clinicians in making detailed and interpretable diagnoses. In this thesis, the AAC algorithms are developed using five large clinical datasets obtained from machines with different manufactures, including patients from Australia, Canada, and the United States, spanning both male and female patients. In conclusion, as DXA scans are commonly captured in various clinical scenarios, this research offers a novel and opportunistic approach to cardiovascular disease detection and monitoring in clinical practice, potentially revolutionizing the way we approach CVD risk screening.

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Elmasri, Karima. "A robust technique for the detection and quantification of abdominal aortic calcification using dual energy X-ray absorptiometry". Thesis, Cardiff University, 2018. http://orca.cf.ac.uk/115458/.

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Arterial calcification is a manifestation of atherosclerosis, which over the last two decades has become a recognised predictor of cardiovascular disease. Abdominal Aortic Calcification (AAC) and osteoporosis have been shown to coincide in older individuals. The accepted method of diagnosing osteoporosis is through the measurement of bone mineral density by dual energy x-ray absorptiometry (DXA). Vertebral fracture assessment (VFA) images obtained alongside BMD using DXA technology provide an inexpensive resource for AAC diagnosis. Although several simple methods have been proposed for manual semi-quantitative scoring of AAC in x-ray images in the past, these methods have limitations in terms of capturing small changes in atherosclerosis progression and are time-consuming. Several automatic approaches have been proposed to measure AAC on radiographs. However, these methods have not been related to any accepted medical AAC scoring systems and thus are not likely to be adopted easily by the medical community. In addition, there has been no attempt to apply the proposed methods to VFA images. The main focus of the research presented in this thesis is the automatic quantification of AAC in VFA images acquired in single energy mode. The thesis is divided into two main parts. In the first part, an automatic method for AAC detection and quantification in VFA images is proposed and evaluated on a large number of images. In the second part, the performance of both single and dual energy VFA imaging for the detection of uniformly distributed calcification is investigated. The automatic method for AAC detection consists of two stages. In the first stage an active appearance model was employed for the purpose of segmentaion. In the second stage, adaptive thresholding techniques were used to detect AAC, whilst automatic iii classification techniques were used to quantify the detected calcification. The performance of several classifiers were investigated, and the proposed method was evaluated against the manual AC-24 scoring method using several hundred images and two human readers. A thorough statistical analysis of the results showed that, overall, the SVM classifier gave the best results. Weighted accuracy, sensitivity, specificity assessed for 4 AAC categories were 89.2%, 78.5% and 92.3% respectively while the corresponding values for 3 AAC categories were 88.6%, 86%, 90.4%. In the second part, a study using a tissue-mimicking physical phantom is described. The phantom consists of an aluminium strip within Perspex to simulate calcification and abdominal soft tissue respectively. VFA images of different phantom configurations were acquired in single energy (SE) and dual energy (DE) modes. The minimum detectable aluminium thickness was assessed visually and related to contrast and contrast-to-noise ratio. Percentage coefficient of variation was used to quantify uniformity, repeatability and reproducibility with a Perspex width of 25 cm, the smallest thickness of aluminium that could be detected was 0.20- 0.25 mm. The initial results are promising, and the system proposed in this research can be used as an alternative method to the manual scoring system (AC-24) for a wide range of AAC. The principal conclusion from the phantom work is that under idealised imaging conditions, VFA images have the potential to be used for detecting small thicknesses of calcification with good linearity, repeatability and reproducibility in SE and DE modes for patients with a body width < 30 cm.

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Coscas, Raphaël. "Remodelage vasculaire dans les modèles expérimentaux d'anévrysme de l'aorte abdominale". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLV025/document.

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La physiopathologie de l’anévrysme de l’aorte abdominale (AAA) est complexe. Elle implique notamment des facteurs hémodynamiques, une protéolyse matricielle, un stress oxydatif et une réaction immune. Des modèles expérimentaux ont été mis au point pour explorer les mécanismes impliqués dans la genèse et la croissance des AAAs. Dans ce travail, nous explorons le rôle de ces modèles dans la compréhension du remodelage vasculaire des AAAs. Dans une première partie, une revue de la littérature sur les modèles expérimentaux d’AAA est menée. Dans une seconde partie, nous explorons l’origine et le rôle des calcifications des AAAs expérimentaux. Dans une troisième partie, le modèle de xénogreffe aortique décellularisée est utilisé pour étudier le rôle de l’immunité adaptative dans la rupture. Notre revue identifie les principaux modèles d’AAA. Leur limite majeure est la survenue d’une cicatrisation empêchant l’évolution vers la rupture. Notre exploration des calcifications anévrysmales retrouve une co-localisation des calcifications avec de l’ADN libre et un modèle expérimental démontre la capacité de l’ADN libre à induire des calcifications. La croissance anévrysmale est toutefois ralentie par les calcifications. Notre étude sur le modèle de xénogreffe décellularisée retrouve la possibilité d’induire une rupture lorsqu’une pré-sensibilisation contre la matrice extracellulaire est réalisée. Les glycoprotéines de structure et les protéoglycanes semblent être les composants matriciels en cause dans ces ruptures. Les modèles expérimentaux constituent des outils majeurs pour l’étude des mécanismes impliqués dans le remodelage vasculaire des AAAs
Pathophysiology of abdominal aortic aneurysms (AAA) is complex. It mainly involves hemodynamics, matrix proteolysis, oxidative stress and an immune reaction. Several experimental models have been described to explore mechanisms involved in this disease. In the present work, we explore the role of experimental models in AAA vascular remodeling. First, a literature review regarding experimental models of AAA is performed. Second, we explore the origin and the role of calcifications observed in experimental models. Third, the decellularized xenograft model is used to study the role of adaptive immunity in triggering rupture. Our review identifies main AAA models. Their major limit is aortic healing, preventing evolution toward rupture. We find that AAA calcifications co-localized with free DNA and that free DNA could induce calcifications experimentally. However, AAA growth is decreased by calcifications. The decellularized xenograft model can evolve toward rupture when pre-sensitization against the extracellular matrix is performed. Structural glycoproteins and proteoglycans seems to be the main matrix component involved in these ruptures. Experimental AAA models are major tools to study mechanisms involved in vascular remodeling

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Tai, Shu-Ching, i 戴淑卿. "Association between Abdominal Fat Distribution and Metabolic Syndrome and Abdominal Aortic Calcification". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/36854884409150205992.

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碩士
國立臺灣大學
流行病學與預防醫學研究所
99
Objectives: The relationship between visceral fat and abdominal aortic calcification among Taiwanese was still unclear. We investigated the association between visceral fat and abdominal aortic calcification in Taiwanese. Material and Methods: We conducted a cross-sectional study of 200 adult participants in a regional hospital during September 2009 to January 2010. Subcutaneous and visceral fat areas were measured on one cross-sectional abdominal CT scan and the calcium score of abdominal aorta were measured within a 4.5cm cylindrical section of abdominal aorta just above aortic bifurcation. Results: The mean age was 50.8 (standard deviation, 14.4) years and 47% were women; 40% had metabolic syndrome and 42.5% had abdominal aortic calcification. The odds ratios (ORs) of abdominal aortic calcification according to tertiles of visceral fat area were 2.1 and 4.2 (95% confidence interval (CI), 1.0-4.5, 2.0-8.7;trend test, p <0.001). After adjusting for age, gender, body mass index (BMI), the OR comparing the participants in the 3rd tertile of visceral fat area with those in the first tertile was 1.5 (95%CI, 0.6-3.6; trend test, p=0.33). We plotted the Receiver Operating Characteristic (ROC) curve of different fat measurements with association of abdominal aortic calcification. The cut-off point for visceral fat area to diagnose aortic calcification was 81.5cm2(sensitivity 75.3%，specificity 51.3%), and the corresponding waist circumference is 84cm in women and 88cm in men. Conclusions: The association between visceral fat area and abdominal aortic calcification were found only in univariate analysis, this association attenuated after multivariate adjustment.

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Neves, Emmanuel Rebelo. "Abdominal Aortic Aneurysm calcification: trying to identify a reliable semiquantitative method". Master's thesis, 2017. https://hdl.handle.net/10216/104571.

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Neves, Emmanuel Rebelo. "Abdominal Aortic Aneurysm calcification: trying to identify a reliable semiquantitative method". Dissertação, 2017. https://repositorio-aberto.up.pt/handle/10216/104571.

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Części książek na temat "Abdominal aortic calcification (AAC)"

Parr, Adam Franklin, i Jonathan Golledge. "Anthropometric Measurements, Adipokines and Abdominal Aortic Calcification". W Handbook of Anthropometry, 2171–84. New York, NY: Springer New York, 2012. http://dx.doi.org/10.1007/978-1-4419-1788-1_133.

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Salahat, Safa, Ahmed Soliman, Harish Bhaskar, Tim McGloughlin, Ayman El-Baz i Naoufel Werghi. "Detection of Calcification from Abdominal Aortic Aneurysm". W Cardiovascular Imaging and Image Analysis, 173–96. Names: El-Baz, Ayman S., editor. | Suri, Jasjit S., editor.Title: Cardiovascular imaging and image analysis / edited by Ayman El-Baz and Jasjit S. Suri.Description: First edition. | Boca Raton : Taylor & Francis, [2019]: CRC Press, 2018. http://dx.doi.org/10.1201/9780429441493-9.

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He, Zinan, Rosaire Mongrain, Simon Lessard i Gilles Soulez. "Extents, Locations and Geometrical Configurations of Calcification in Abdominal Aortic Aneurysm". W EMBEC & NBC 2017, 639–42. Singapore: Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-5122-7_160.

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Saleem, Afsah, Zaid Ilyas, David Suter, Ghulam Mubashar Hassan, Siobhan Reid, John T. Schousboe, Richard Prince, William D. Leslie, Joshua R. Lewis i Syed Zulqarnain Gilani. "SCOL: Supervised Contrastive Ordinal Loss for Abdominal Aortic Calcification Scoring on Vertebral Fracture Assessment Scans". W Lecture Notes in Computer Science, 273–83. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-43987-2_27.

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Ilyas, Zaid, Afsah Saleem, David Suter, John T. Schousboe, William D. Leslie, Joshua R. Lewis i Syed Zulqarnain Gilani. "A Hybrid CNN-Transformer Feature Pyramid Network for Granular Abdominal Aortic Calcification Detection from DXA Images". W Lecture Notes in Computer Science, 14–25. Cham: Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-72120-5_2.

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Gilani, Syed Zulqarnain, Naeha Sharif, David Suter, John T. Schousboe, Siobhan Reid, William D. Leslie i Joshua R. Lewis. "Show, Attend and Detect: Towards Fine-Grained Assessment of Abdominal Aortic Calcification on Vertebral Fracture Assessment Scans". W Lecture Notes in Computer Science, 439–50. Cham: Springer Nature Switzerland, 2022. http://dx.doi.org/10.1007/978-3-031-16437-8_42.

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Streszczenia konferencji na temat "Abdominal aortic calcification (AAC)"

Bluestein, Danny, Yared Alemu, Peter Rissland, Mikahil Britan, Idit Avrahami, Shmuel Einav i John Ricotta. "Risk of Rupture in AAA and Vulnerable Plaques: Patient Based FSI Simulation". W ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-176781.

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Two separate fluid structure interaction (FSI) simulations were performed: a patient-specific Abdominal Aortic Aneurysm (AAA) geometry, and an idealized coronary vulnerable plaque (VP) geometry. VP FSI simulations were later performed in patient based geometries reconstructed from intravascular (IVUS) measurements. (AAA): The patient specific AAA FSI simulation was carried out with both isotropic and anisotropic wall properties. An orthotropic material model was used to describe wall properties, closely approximate experimental results [1]. Results show peak wall stresses are dependent on the geometry of the AAA and the region of highest stress corresponds to expected failure location. The ability to quantify stresses developing within the aneurysm wall based on FSI simulations will facilitate clinicians to reach informed decisions in determining rupture risk of AAA and the need for surgical intervention. (Vulnerable Plaque): To study the risk of rupture of a vulnerable plaque in an idealized coronary artery geometry, an FSI simulation was performed. This model of vulnerable plaque includes vessel wall with calcification spot embedded in the fibrous cap, and a lipid core. Identifying rupture risk, regions susceptible to failure and the contribution of the various components were studied. This work led to predicting the rupture risk in patient specific geometries. The results show the upstream side of vulnerable plaque fibrous cap has the highest stresses. The presence of the calcified spot is shown to enhance stresses within the fibrous cap, significantly contributing to its risk of rupture.

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Xenos, Michalis, Suraj Rambhia, Yared Alemu, Shmuel Einav, John J. Ricotta, Nicos Labropoulos, Apostolos Tassiopoulos i Danny Bluestein. "A Fluid Structure Interaction Approach for Patient Based Abdominal Aortic Aneurysm Rupture Risk Prediction". W ASME 2010 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/sbc2010-19298.

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Fluid structure interaction (FSI) simulations of patient-specific fusiform non-ruptured and contained ruptured Abdominal Aortic Aneurysm (AAA) geometries were conducted. The goals were: (1) to test the ability of our FSI methodology to predict the location of rupture, by correlating the high wall stress regions with the rupture location, (2) estimate the state of the pathological condition by calculating the ruptured potential index (RPI) of the AAA and (3) predict the disease progression by comparing healthy and pathological aortas. The patient specific AAA FSI simulations were carried out with advanced constitutive material models of the various components of AAA, including models that describe wall anisotropy based on collagen fibers orientation within the arterial wall, structural strength of the aorta, intraluminal thrombus (ILT), and embedded calcifications. The anisotropic material model used to describe the wall properties closely correlated with experimental results of AAA specimens. The results demonstrate that the anisotropic wall simulations showed higher peak wall stresses as compared to isotropic material models, indicating that the latter may underestimate the AAA risk of rupture. The ILT appeared to provide a cushioning effect reducing the stresses, while small calcifications (small-Ca) appeared to weaken the wall and contribute to the rupture risk. FSI simulations with ruptured AAA demonstrated that the location of the maximal wall stresses and RPI overlap the actual rupture region.

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van Dam, Evelyne, Marcel Rutten i Frans van de Vosse. "Local Mechanical Properties of Abdominal Aortic Aneurysms". W ASME 2008 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2008. http://dx.doi.org/10.1115/sbc2008-192892.

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Rupture risk of abdominal aortic aneurysms (AAA) based on wall stress analysis may be superior to the currently used diameter-based rupture risk prediction [4; 5; 6; 7]. In patient specific computational models for wall stress analysis, the geometry of the aneurysm is obtained from CT or MR images. The wall thickness and mechanical properties are mostly assumed to be homogeneous. The pathological AAA vessel wall may contain collageneous areas, but also calcifications, cholesterol crystals and large amounts of fat cells. No research has yet focused yet on the differences in mechanical properties of the components present within the degrading AAA vessel wall.

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Xenos, Michalis, Suraj Rambhia, Yared Alemu, Shmuel Einav, John J. Ricotta, Nicos Labropoulos, Apostolos Tassiopoulos i Danny Bluestein. "A Patient Based Approach for Fluid Structure Interaction in Ruptured Abdominal Aortic Aneurysms". W ASME 2009 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2009. http://dx.doi.org/10.1115/sbc2009-206490.

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Fluid structure interaction (FSI) simulations were conducted to assess the risk of rupture in reconstructed AAA from patients who had contained ruptured AAAs. The goal was to test to ability of our FSI methodology to predict the location of rupture, by correlating the high wall stress regions with the actual rupture location. We also present a parametric study in which the relationship of iliac bifurcation angle and the role of embedded calcifications were studied in respect to the aneurismal wall stress. The patient specific AAA FSI simulations were carried out with advanced constitutive material models of the various components of AAA, including models that describe the wall anisotropy, structural strength based on collagen fibers orientation within the arterial wall, AAA intraluminal thrombus (ILT), and embedded calcifications. The anisotropic material model used to describe the wall properties closely correlated with experimental results of AAA specimens [1]. The results demonstrate that the region of rupture can be predicted by the region of the highest wall stress distribution. Embedded wall calcifications increase the local wall stress surrounding calcified spots, and eventually increases the risk of rupture. FSI results in streamlined AAA geometries show that the maximum stress on the aneurismal wall increases as the iliac bifurcation angle increases.

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van Dam, Evelyne, Marcel Rutten i Frans van de Vosse. "Discrimination of Vessel Wall Components of Abdominal Aortic Aneurysms by Multi-Contrast MRI". W ASME 2008 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2008. http://dx.doi.org/10.1115/sbc2008-192886.

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Rupture of an abdominal aortic aneurysm (AAA) is a major cause of death in the Western world. When the AAA is diagnosed timely, rupture can be prevented by conventional surgical or by endovascular repair. To date, the decision to operate is based on geometry alone, but it has already been suggested that wall stress would be a better predictor [2]. Patient specific computational models have been developed to calculate wall stress [2; 5; 9; 8; 10]. In these models, the AAA wall is assumed to be homogeneous. Patient-specific inhomogeneities such as atherosclerotic plaques and calcifications have large effects on the maximum wall stress and wall stress distribution [6; 7]. Histological examination is not feasible for determining wall composition of patients.

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Di Martino, Elena S., David H. J. Wang, Alberto Redaelli, Michel S. Makaroun i David A. Vorp. "Effect of Variations in Intraluminal Thrombus Constitutive Properties on Abdominal Aortic Aneurysm Wall Stress: A Parametric Study". W ASME 2001 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/imece2001/bed-23120.

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Abstract The prevalence of abdominal aortic aneurysm (AAA) is growing together with population age, being 8.8% in a population above 65 years according to a recent study [1]. Deciding between elective surgical repair of AAA and watchful management is a complex issue due to the lack of reliable rupture risk indices. The maximum transverse diameter of AAA is most commonly used in clinical practice to base this decision. From a biomechanical viewpoint, AAA rupture is related to the balance between the stresses acting on the wall and strength of the wall tissue. Many different factors contribute to the stress within the aortic aneurysm wall, including the presence of intraluminal thrombus (ILT) [2–5], the local surface curvature [6] and material characteristics of the AAA wall [7], and the presence of local “stress concentrators” due to calcifications or local thinning. As regards the ILT, its role with respect to aneurysm wall stresses has given rise to many hypotheses. Some studies show that the pressure inside the thrombus is not reduced with respect to the arterial blood pressure, some, including studies from the authors, state a possible protective role [2–5]. Previously in our laboratory, a nonlinear, hyperelastic constitutive model was developed for ILT, and the parameters for which were determined through ex-vivo experimentation [8]. The purpose of this study was to investigate the reliability of using the same population-mean values of ILT constitutive parameters for estimates of wall stress distribution in all AAA. For this, we performed a parametric study in which the ELT constitutive parameters were varied within a physiological range and aortic wall stresses were evaluated.

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Muzasti, R. A., i R. Loesnihari. "Prevalence of Abdominal Aortic Calcification in Maintenance Hemodialysis Patients". W International Conference of Science, Technology, Engineering, Environmental and Ramification Researches. SCITEPRESS - Science and Technology Publications, 2018. http://dx.doi.org/10.5220/0010076705090513.

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Izumi, K., M. Noguchi, E. Iwasaki, K. Deguchi i S. Shirakawa. "VASCULAR DAMAGE IN PATIENTS ON CHRONIC HEMODIALYSIS". W XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643346.

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Calcification in the abdominal artery and endothelial cell function of the peripheral veins were studied in the patients recieving maintenance hemodialysis for the chronic renal failure.The grade of calcification was expressed by the aortic calcification index (ACI) calculation from the abdominal CT scan films. The endothelial cell function was estimated from the release capasity for tissue plasminogen activator (t-PA) and von Willebrand factor (vWF), and the fibrinolytic capacity (by ELT and fibrin plate lysis area) during 10-min venous occlusion (VO) of the cubital vein. The dialysed patients were divided into 4 groups according to the duration of hemodialysis : group A ; under 1 year (n=7), group B ; 1-4 years (n=14), group C ; 4-7 years (n=15) and group D ; 7-10 years (n=8).The level (X + SD) of vWF : Ag, vWF act. (RCoF) and t-PA in patients before VO were 439 ± 255(%),171 ± 42(%), 4.2 ± 0.6(ng/ml) in group A, 292 ± 157, 151 ± 35, 4.1 ± 1.2 in group B, 174 ± 114, 133 ± 47, 3.7 ± 0.8 in group C and 130 + 27, 66 ± 21, 3.1 ± 0.7 in group D, respectively. With the increase in the duration of hemodialysis, the release capacity for vWF and t-PA, and the fibrinolytic capacity during VO decreased regardless of the aggravation of fibrinolytic activity before VO, When the activity was estimated by ELT, Cl-inactivator resistant fibrinolytic activity and fibrin lysis area. These findings are thought to reflect the exhaustion of endotherial cells. In elder patients (60-80 years old), the release capacity for vWF and t-PA during VO decreased with the increase in the ACI level.It is conclude that the patients on chronic hemodialysis have a greater incidence of calcification of abdominal artery and lower function of endothelial cells in the cubital vein than non-dialysed control.

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Ghozlani, I., A. El Maataoui, M. Ghazi, A. Kherrab i R. Niamane. "FRI0548 Influence of homocysteine and vertebral fractures on prevalent abdominal aortic calcification in postmenopausal women: a multicentric cross-sectional study". W Annual European Congress of Rheumatology, 14–17 June, 2017. BMJ Publishing Group Ltd and European League Against Rheumatism, 2017. http://dx.doi.org/10.1136/annrheumdis-2017-eular.1447.

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Raporty organizacyjne na temat "Abdominal aortic calcification (AAC)"

Sheng, Chang, Weihua Huang, Mingmei Liao i Pu Yang. Association of the Abdominal Aortic Calcification with All-Cause and Cardiovascular Disease-Specific Mortality: Prospective Cohort Study. World Journal of Surgery, kwiecień 2024. http://dx.doi.org/10.60123/j.wjs.2024.10.03.

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Background: Abdominal aortic calcification (AAC) is a prevalent form of vascular calcification associated with adverse cardiovascular outcomes. While previous studies on AAC and cardiovascular risk exist, many have limitations such as small sample sizes and limited clinical significance outcomes. This study aims to prospectively investigate the association between AAC and all-cause and cardiovascular disease (CVD)-specific mortality rates in a nationally representative sample of adults in the United States, using data from the National Health and Nutrition Examination Survey (NHANES). Methods: The study, conducted on NHANES participants aged 40 years or older during the 2013-2014 cycle, assessed AAC using the Kauppila scoring system. Demographic characteristics, mortality data, and comorbid factors such as age, gender, diabetes, and hypertension were considered. Statistical analyses, including weighted percentages, Kaplan-Meier survival curves, and multivariable Cox proportional hazards regression models, were employed to evaluate the associations between AAC and mortality risks. Results: After analyzing a final sample of 2717 participants, the study found a significant association between severe AAC (SAAC) and higher all-cause mortality risk (HR 1.70, 95% CI 1.17-2.48). The dose-response relationship indicated an increased risk with higher AAC scores. However, no independent association was observed between AAC and cardiovascular mortality. Stratified analysis revealed variations in the AAC-all-cause mortality association based on gender and hypertension. Conclusion: This population-based study provides valuable insights into the prospective association between AAC and all-cause mortality, emphasizing the potential role of AAC assessment in identifying individuals at higher risk.

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