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Image Edge Detection Using Fractional Conformable Derivatives in Liouville-Caputo Sense for Medical Image Processing
Published in Devendra Kumar, Jagdev Singh, Fractional Calculus in Medical and Health Science, 2020
J. E. Lavín-Delgado, J. E. Solís-Pérez, J. F. Gómez-Aguilar, R. F. Escobar-Jiménez
The aorta is the body’s major blood vessel [65]. An abdominal aortic aneurysm (AAA) is a blood-filled bulge or ballooning in a part of your aorta that runs through the abdomen [66]. It usually causes no symptoms, except during rupture, which may result in pain in the abdomen or back, low blood pressure, or loss of consciousness, and often results in death [67]. The presence of an AAA can be confirmed with an abdominal ultrasound, abdominal and pelvic CT, or angiography. [68]. Figures 1.17 through 1.19 taken from [69–71], respectively show 3D maximum intensity projection (MIP) MRI images. These figures show that the proposed approach improves the detection and the segmentation of the aortic wall. This improvement represents a diagnostic system that allows analyses the abdominal MRI and warns if an abnormality is detected.
Aortic and Arterial Mechanics
Published in Michel R. Labrosse, Cardiovascular Mechanics, 2018
The exact causes of AAA are not yet well known. Nevertheless, several risk factors are involved in their occurrence: HBP [41]Smoking or smoking history [46]Family history, suggesting genetic factors [47]Age, sex [41], and ethnicity (much lower prevalence in Asian populations) [48]Atherosclerosis [49]Obesity [50]
Cardiovascular system
Published in David A Lisle, Imaging for Students, 2012
Abdominal aortic aneurysm (AAA) is generally defined as an abdominal aortic diameter of greater than 3 cm. AAA is usually caused by weakening of the aortic wall due to atherosclerosis. This weakening leads to dilatation of the aorta, which is usually progressive. AAA may present clinically as a pulsatile abdominal mass or occasionally with acute abdominal pain due to leakage. More commonly, AAA is an incidental finding on imaging performed for other reasons including US or CT of the abdomen, or X-ray of the lumbar spine. Plain-film signs of AAA may include a soft tissue mass with curvilinear calcification.
CFD analysis of the hyper-viscous effects on blood flow across abdominal aortic aneurysm in COVID patients: multiphysics approach
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Shankar Narayan S., Anuradha Bhattacharjee, Sunanda Saha
It is known that aortic aneurysms can develop in and below the chest. When opposed to aneurysms that develop below the chest region, thoracic aortic aneurysms (TAAs) occur less often (Abdominal Aortic Aneurysm, [AAA]). Due to the AAA’s frequency of occurrence as compared to TAA, we have taken it into consideration for analysis in this study. An enlarged aorta with a thickness that is at least 1.5 times the width of the aorta as evaluated at the level of the renal arteries is referred to as an AAA. The average person’s normal abdominal aorta has a diameter of about 2.0 cm (range from 1.4 to 3.0 cm). Practically, a AAA is identified when the aortic diameter is more than 3.0 cm (Hirsch et al. 2006; Erbel and Eggebrecht 2006; Gameraddin 2019). An AAA is frequently brought on by pre-existing medical diseases, such as atherosclerosis and the effects of smoking and high blood pressure. The circulation may be directed toward a specific location on the inner wall of the arterial vessel due to pressure from the aortic atherosclerotic stenosis, which may cause the wall to protrude into the outer arterial areas (Ke et al. 2021; Narayan and Saha 2021).
On the importance of tunica intima in the aging aorta: a three-layered in silico model for computing wall stresses in abdominal aortic aneurysms
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Mario de Lucio, Marcos Fernández García, Jacobo Díaz García, Luis Esteban Romera Rodríguez, Francisco Álvarez Marcos
An abdominal aortic aneurysm (AAA) is a balloon-like, localized enlargement of the aorta that bulges out beyond the normal diameter of the blood vessel. AAAs affect about 3% of the world population over the age of 50 (LeFevre 2014). Associated risk factors are mostly lifestyle-related (smoking, dyslipidemia, high blood pressure), although a heritable component can also play a role. They usually remain asymptomatic until rupture, which can lead to life-threatening internal bleeding with an in-hospital mortality of about 40% and a pre-hospitalization overall mortality of 80% (Kühnl et al. 2017). Repair of an AAA may be done either by open surgery or endovascular aneurysm repair (EVAR). Open repair, as any surgical procedure, may associate with a non-negligible rate of complications such as bleeding during or after surgery, myocardial infarction, respiratory impairment or graft infection. On the other hand, EVAR is a minimally invasive technique that only requires small incisions in the groin, but requires a more strict postoperative surveillance over time.
A systematic review of standardized methods for assessment of endograft sealing on computed tomography angiography post-endovascular aortic repair, and its influence on endograft-associated complications
Published in Expert Review of Medical Devices, 2019
Richte C.L. Schuurmann, Philippe M. De Rooy, Frederico Bastos Gonçalves, Cornelis G. Vos, Jean-Paul P.M. De Vries
Baderkhan et al. also examined whether it may be possible to identify patients at low risk of complications based on their first postoperative CTA[5]. Apposition length in the proximal and distal landing zones was measured with method A on the first postoperative CTA scan in a series of 326 patients. Patients were categorized as high risk (n = 114) or low-risk (n = 212) and were considered high risk when they had short proximal and/or distal seal zone and/or any endoleak on the first postoperative CT scan. Aortic neck length was similar between the high-risk (23.8 ± 13.8 mm) and low-risk (22.0 ± 13.9 mm) patients. High-risk patients had increased risk for AAA-related complications (migration >10 mm, AAA growth >5 mm, rupture, or endoleak type IA, IB, III, or undefined) and AAA-associated re-intervention during 4.8 ± 3.2 years of follow-up. Short proximal apposition length was associated with an odds ratio of 26.6, and short distal apposition length was associated with an odds ratio of 37.6 for AAA-related events.