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Central nervous system
Published in David A Lisle, Imaging for Students, 2012
Most cerebral artery aneurysms are congenital ‘berry’ aneurysms. Berry aneurysms occur in 2 per cent of the population and are multiple in 10 per cent of cases. Increased incidence of berry aneurysms occurs in association with coarctation of the aorta and autosomal dominant polycystic kidney disease. Most berry aneurysms occur around the circle of Willis, the most common sites being:Anterior communicating arteryPosterior communicating arteryMiddle cerebral arteryBifurcation of internal carotid arteryTip of basilar artery.
Coanda Effect in a Human Body
Published in Noor A. Ahmed, Coanda Effect, 2019
The majority of the cerebral aneurysms are found to be in the anterior segment of the Circle of Willis, and can be found in three main arteries: the internal carotid artery, the middle cerebral artery, and the anterior cerebral artery. There are others in the basilar artery, vertebral basilar, posterior communicating artery, and cavernous carotid artery.
Neuroimaging
Published in Sarah McWilliams, Practical Radiological Anatomy, 2011
Fig. 1.29 Diagram of the base of the skull showing the vertebral arteries joining to form the basilar artery and the circle of Willis: optic chiasma (1); internal carotid artery (2); anterior cerebral artery (3); and posterior communicating artery (4).
Hemodynamic simulation of intracranial aneurysm growth with virtual silk stent implantation
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2018
Xiao Mo, Qianqian Meng, Xiangyu Ma, Qianqian Zhang, Hongyu Yu, Bin Jing, Han Liu, Qi Yan, Zhizheng Zhuo, Xinjian Yang, Haiyun Li
We enrolled 12 patients from Beijing Tiantan Hospital, whose IAs were located at the internal carotid posterior communicating artery. These participants gave their informed consents and the Ethics Committee of Beijing Tiantan Hospital Affiliated to Capital Medical University approved the protocol of this study. The patient-specific 3D rotational angiography (3DRA) images were acquired from a GE LCV + Digital Subtraction system (LCV; GE Medical Systems) during a 200° rotation at the rate of 8.8 frames/s. All 88 projection images were converted into a 3D dataset by using isotropic voxels on a dedicated GE workstation (Advantage Unix; GE Medical Systems). Then the raw DICOM file was imported into software Mimics 13.0 (Belgium Materialize company). The IA morphology was extracted by adopting an image cropping threshold and further converted into a triangulated surface model. The blood vessel wall was constructed by extracting the surface along the normal direction of the wall in Geomagic 12 software (Raindrop Geomagic, Durham, USA). Thus, the original geometrical models of IA were constructed, see Figure 1.
Recent advances in stent-assisted coiling of cerebral aneurysms
Published in Expert Review of Medical Devices, 2020
Soliman Oushy, Lorenzo Rinaldo, Waleed Brinjikji, Harry Cloft, Giuseppe Lanzino
The tip of the coiling microcatheter is first placed within the aneurysm fundus followed by stent deployment across the aneurysm neck, effectively ‘jailing’ the microcatheter against the parent vessel wall by the expanding stent. Relative to the ‘coil-through’ technique, the ‘jailing’ method has the benefit of facilitating access to the aneurysm fundus which can be a challenging task, as well as stabilizing the coiling microcatheter during coil deployment. Figure 3 illustrates the jailing technique used to treat a left posterior communicating artery aneurysm in an elderly female with bilateral vertebral artery and right internal carotid artery occlusion.
Effects of progressive carotid stenosis on cerebral haemodynamics: aortic-cerebral 3D patient-specific simulation
Published in Engineering Applications of Computational Fluid Mechanics, 2021
Taehak Kang, Debanjan Mukherjee, Jeong-Min Kim, Kwang-Yeol Park, Jaiyoung Ryu
The circle of Willis (CoW) is a principal collateral structure that maintains cerebral circulation in response to brain ischaemia, mainly caused by carotid stenosis (CS). The posterior communicating artery (PCoA) and anterior communicating artery (ACoA) serve as collateral links between the anterior and posterior cerebral circulation while reducing the incidence of stroke and transient ischaemic attack (TIA) in both long-term and perioperative follow-up periods (Henderson et al., 2000; Zhou et al., 2016). Incomplete CoW is present in approximately 50–79% of the population (Alpers et al., 1959; Kapoor et al., 2008; Lippert & Pabst, 1985; Papantchev et al., 2013; Riggs & Rupp, 1963) adopting various forms and causing issues such as anterior circulation (Henderson et al., 2000) and lacunar infarctions (Chuang et al., 2008). One important finding is that PCoA hypoplasia is asymptomatic without ipsilateral internal carotid artery (iICA) stenosis (Schomer et al., 1994), but is also a risk factor even without the iICA stenosis (Chuang et al., 2008). This highlights the importance of a more comprehensive study; other confusions also arise: a higher degree of CS is related to the presence of more collaterals (Adams et al., 1999; Hoksbergen et al., 2000; Miyazawa et al., 2011; Morgenstern et al., 1997) but patients with more collaterals had better 90-day (Zhou et al., 2016) and long-term prognoses (Henderson et al., 2000; Kim et al., 2016). The above correlations, however, are reversed in asymptomatic cases as collaterals are less present in such cases than in the symptomatic cases (Hendrikse et al., 2001), with the former experiencing lower benefit from medical intervention (Halliday, 2004; Moneta et al., 1993; Rothwell et al., 1994) implying favorable clinical outcomes even with fewer collaterals. Such contradicting findings may be due to the complexity involved in analyzing the complex anatomy of the individual arterial network in conventional medical approaches and the challenge involved in the patient-specific tracking of CS progression. Alternatively, the correlation between CoW variation and CS is not yet fully understood, as a review (Chatzikonstantinou et al., 2012) suggested that patient-specific follow-up in short time windows is a better clinical approach.