scholarly journals Relationship between Circle of Willis Variations and Cerebral or Cervical Arteries Stenosis Investigated by Computer Tomography Angiography and Multitask Convolutional Neural Network

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Jin Hou ◽  
Ming Yong Gao ◽  
Ai Zhen Pan ◽  
Qiu Dian Wang ◽  
Bin Liu ◽  
...  
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Cerebral Artery ◽  
Computer Tomography ◽  
Cerebral Arteries ◽  
Circle Of Willis ◽  
Anterior Communicating Artery ◽  
Visual Evaluation ◽  
Cerebral Vessel ◽  
Computer Tomography Angiography

Circle of Willis (CoW) is the most critical collateral pathway that supports the redistribution of blood supply in the brain. The variation of CoW is closely correlated with cerebral hemodynamic and cerebral vessel-related diseases. But what is responsible for CoW variation remains unclear. Moreover, the visual evaluation for CoW variation is highly time-consuming. In the present study, based on the computer tomography angiography (CTA) dataset from 255 patients, the correlation between the CoW variations with age, gender, and cerebral or cervical artery stenosis was investigated. A multitask convolutional neural network (CNN) was used to segment cerebral arteries automatically. The results showed the prevalence of variation of the anterior communicating artery (Aco) was higher in the normal senior group than in the normal young group and in females than in males. The changes in the prevalence of variations of individual segments were not demonstrated in the population with stenosis of the afferent and efferent arteries, so the critical factors for variation are related to genetic or physiological factors rather than pathological lesions. Using the multitask CNN model, complete cerebral and cervical arteries could be segmented and reconstructed in 120 seconds, and an average Dice coefficient of 78.2% was achieved. The segmentation accuracy for precommunicating part of anterior cerebral artery and posterior cerebral artery, the posterior communicating arteries, and Aco in CoW was 100%, 99.2%, 94%, and 69%, respectively. Artificial intelligence (AI) can be considered as an adjunct tool for detecting the CoW, particularly related to reducing workload and improving the accuracy of the visual evaluation. The study will serve as a basis for the following research to determine an individual’s risk of stroke with the aid of AI.

scholarly journals Anatomical variations of circle of Willis - a cadaveric study

2017 ◽  
Vol 4 (4) ◽  
pp. 1249 ◽  
Author(s):  
Ramanuj Singh ◽  
Ajay Babu Kannabathula ◽  
Himadri Sunam ◽  
Debajani Deka
Keyword(s):  
Cerebral Artery ◽  
Anterior Cerebral Artery ◽  
Anterior Part ◽  
Cerebral Arteries ◽  
Anatomical Variations ◽  
Circle Of Willis ◽  
Anterior Communicating Artery ◽  
Surgical Interventions ◽  
Collateral Channel ◽  
The Right

Background: The circle of Willis (CW) is a vascular network formed at the base of skull in the interpeduncular fossa. Its anterior part is formed by the anterior cerebral artery, from either side. Anterior communicating artery connects the right and left anterior cerebral arteries. Posteriorly, the basilar artery divides into right and left posterior cerebral arteries and each join to ipsilateral internal carotid artery through a posterior communicating artery. Anterior communicating artery and posterior communicating arteries are important component of circle of Willis, acts as collateral channel to stabilize blood flow. In the present study, anatomical variations in the circle of Willis were noted.Methods: 75 apparently normal formalin fixed brain specimens were collected from human cadavers. 55 Normal anatomical pattern and 20 variations of circle of Willis were studied. The Circles of Willis arteries were then colored, photographed, numbered and the abnormalities, if any, were noted.Results: Twenty variations were noted. The most common variation observed is in the anterior communicating artery followed by some other variations like the Posterior communicating arteries, Anterior cerebral artery and posterior cerebral artery (PCA) was found in 20 specimens.Conclusions: Knowledge on of variations in the formation of Circle of Willis, all surgical interventions should be preceded by angiography. Awareness of these anatomical variations is important in the neurovascular procedures.

Wall Shear Stress and Gradient at Anterior Communicating Artery in Pulsating Flow

2000 ◽  
Author(s):  
Ryuhei Yamaguchi ◽  
Susumu Kudo ◽  
Hiroyuki Yamanobe ◽  
Mikio Nakajima ◽  
Hiroshi Ujiie
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Cerebral Artery ◽  
Major Part ◽  
Cerebral Arteries ◽  
Circle Of Willis ◽  
Pulsating Flow ◽  
Anterior Communicating Artery ◽  
Wall Shear

Abstract The aneurysm in the cerebral artery is apt to initiate around the “Circle of Willis”. The anterior communicating artery (ACoA), which composes one of major part of the circle of Willis, is the most predilection artery of the aneurysm. This artery is characterized by a singular geometry. At this artery, two proximal anterior cerebral arteries (A1, confluence) join facing each other. Just at this artery, the flow bifurcates two distal anterior cerebral arteries (A2, bifurcation). Namely, this artery has a function as a bypass channel. Therefore, the flow around the anterior communicating artery would be very unstable. The aneurysm arises around the apex of this artery where the confluent flow collides.

scholarly journals Study of variations of the anterior cerebral artery in human brain

2013 ◽  
Vol 02 (03) ◽  
pp. 122-127
Author(s):  
Bishwajeet Saikia ◽  
Kunjalal Talukdar ◽  
Joydev Sarma ◽  
Amitav Sarma ◽  
Sandeep Madaan
Keyword(s):  
Cerebral Artery ◽  
Anterior Cerebral Artery ◽  
Cerebral Arteries ◽  
Initial Step ◽  
Circle Of Willis ◽  
Anatomical Distribution ◽  
Surgical Interventions ◽  
Medical College ◽  
The Individual ◽  
Considerable Individual Variation

Abstract Background and aims: Stroke, the most frequent expression of cerebrovascular disease is one of the leading causes of death and disability throughout the world. The manifestations are largely accounted by the anatomical distribution of the stems and branches of the circle of Willis supplying the brain. Considerable individual variation exists in the pattern and caliber of the individual vessels forming the circle of Willis, which may possibly impair the collateral blood flow. The knowledge of these variations thus, becomes essential for medical as well as surgical interventions. There may possibly be some regional variations in the cerebral arteries not mentioned in standard available texts. Thus, the regional based study of variations present becomes essential. The present study aims to focus on the variation of one of such branches, the anterior cerebral artery (ACA) in the population of Assam, India. Material and Methods: The ACAs of 70 human cadaveric brains were examined by gross dissection in the department of Anatomy and Forensic medicine in Gauhati Medical College. Results: Hypoplastic A-1 segment were found in 7% cases, Hypoplastic A-2 segment in 2.85% cases, Buttonhole formation in 8.57% cases and aneurysmal dilatation in 1.42% cases. The results were compared with that of other authors and variations noted. Conclusion: The present study of ACA using gross dissection is an initial step in providing a reference to the healthcare professionals in the region of Assam. Based on this further studies using newer imaging methods should be carried out to correlate the manifestations clinically.

Bifurcation geometry and the presence of cerebral artery aneurysms

2004 ◽  
Vol 101 (1) ◽  
pp. 108-113 ◽  
Author(s):  
Tor Ingebrigtsen ◽  
Michael K. Morgan ◽  
Ken Faulder ◽  
Linda Ingebrigtsen ◽  
Trygve Sparr ◽  
...  
Keyword(s):  
Cerebral Artery ◽  
Geometric Model ◽  
Cerebral Arteries ◽  
Multivariate Logistic Regression Analysis ◽  
Circle Of Willis ◽  
Parent Vessel ◽  
Content Type ◽  
Optimality Principles ◽  
The Relationship ◽  
Fine Print

Object. The angles of arterial bifurcations are governed by principles of work minimization (optimality principle). This determines the relationship between the angle of a bifurcation and the radii of the vessels. Nevertheless, the model is predicated on an absence of significant communication between these branches. The circle of Willis changes this relationship because the vessels proximal to the ring of vessels have additional factors that determine work minimization compared with more distal branches. This must have an impact on understanding of the relationship between shear stress and aneurysm formation. The authors hypothesized that normal bifurcations of cerebral arteries beyond the circle of Willis would follow optimality principles of minimum work and that the presence of aneurysms would be associated with deviations from optimum bifurcation geometry. Nevertheless, the vessels participating in (or immediately proximal to) the circle of Willis may not follow the geometric model as it is generally applied and this must also be investigated. Methods. One hundred seven bifurcations of the middle cerebral artery (MCA), distal internal carotid artery (ICA), and basilar artery (BA) were studied in 55 patients. The authors analyzed three-dimensional reconstructions of digital subtraction angiography images with respect to vessel radii and bifurcation angles. The junction exponent (that is, a calculated measure of the division of flow at the bifurcation) and the difference between the predicted optimal and observed branch angles were used as measures of deviation from the geometry thought best to minimize work. The mean junction exponent for MCA bifurcations was 2.9 ± 1.2 (mean ± standard deviation [SD]), which is close to the theoretical optimum of 3, but it was significantly smaller (p < 0.001; 1.7 ± 0.8, mean ± SD) for distal ICA bifurcations. In a multilevel multivariate logistic regression analysis, only the observed branch angles were significant independent predictors for the presence of an aneurysm. The odds ratio (OR) (95% confidence interval) for the presence of an aneurysm was 3.46 (1.02–11.74) between the lowest and highest tertile of the observed angle between the parent vessel and the largest branch. The corresponding OR for the smallest branch was 48.06 (9.7–238.2). Conclusions. The bifurcation beyond the circle of Willis (that is, the MCA) closely approximated optimality principles, whereas the bifurcations within the circle of Willis (that is, the distal ICA and BA) did not. This indicates that the confluence of hemodynamic forces plays an important role in the distribution of work at bifurcations within the circle of Willis. In addition, the observed branch angles were predictors for the presence of aneurysms.

scholarly journals The role of anatomical anomalies in anterior communicating artery aneurysm rupture

2013 ◽  
Vol 19 (3) ◽  
pp. 147-153
Author(s):  
Cr.P Dimitriu ◽  
C. Ionescu ◽  
P. Bordei ◽  
I. Bulbuc
Keyword(s):  
Cerebral Artery ◽  
Anterior Cerebral Artery ◽  
Cerebral Aneurysms ◽  
Artery Aneurysm ◽  
Aneurysm Rupture ◽  
Circle Of Willis ◽  
Control Group ◽  
Anterior Communicating Artery ◽  
Aneurysm Size ◽  
Proper Patient Selection

Abstract Background and purpose:limited data exist to guide proper patient selection for preventive treatment of unruptured cerebral aneurysms. Cerebral aneurysms have been associated with anomalies of arterial segments that are forming the brain arterial circle of Willis but whether this association is also related to aneurysm rupture is not known. The occurrence of cerebral aneurysm rupture when a circle of Willis anomaly was present or absent was compared. Material and methods: we have performed this study on a number of 312 cases, of which 87 were dissections, 22 dissection followed by plastic injection, 135 magnetic resonance angiography (MRA), 75 computer tomography angiography (CTA), 40 digital subtraction angiographies (DSA), 30 in vivo (intraoperatory) observation. Brain vascular imaging was reviewed for aneurysm size, morphology and presence of anterior cerebral artery anomalies. Results: we divided the study group in 2 cohorts, one control group of 272 cases, in which we have study the anatomical variants occurrence and aneurysm occurrence in general population and another included 45 patients admitted thru emergency room for subarachnoid hemorrhage, of those 38 were ruptured aneurysm of anterior communicating artery (ACoA). Mean aneurysm size was 8.9 mm. An anterior cerebral artery anomaly was identified in 31 cases (81.5%). Multivariate analysis revealed a higher risk of aneurysm rupture when an anterior cerebral artery was present. Conclusions: this study shows that anterior cerebral artery anomalies are more commonly found in ruptured as opposed to unruptured ACoA aneurysms. The presence of an ACA anomaly may be an important characteristic for selecting patients for preventive aneurysm treatment.

scholarly journals Brain CT registration using hybrid supervised convolutional neural network

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Hongmei Yuan ◽  
Minglei Yang ◽  
Shan Qian ◽  
Wenxin Wang ◽  
Xiaotian Jia ◽  
...  
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Soft Tissues ◽  
Ct Images ◽  
Registration Accuracy ◽  
Visual Evaluation ◽  
Normalized Mutual Information ◽  
Brain Ct ◽  
Visual Spatial ◽  
The Mean

Abstract Background Image registration is an essential step in the automated interpretation of the brain computed tomography (CT) images of patients with acute cerebrovascular disease (ACVD). However, performing brain CT registration accurately and rapidly remains greatly challenging due to the large intersubject anatomical variations, low resolution of soft tissues, and heavy computation costs. To this end, the HSCN-Net, a hybrid supervised convolutional neural network, was developed for precise and fast brain CT registration. Method HSCN-Net generated synthetic deformation fields using a simulator as one supervision for one reference–moving image pair to address the problem of lack of gold standards. Furthermore, the simulator was designed to generate multiscale affine and elastic deformation fields to overcome the registration challenge posed by large intersubject anatomical deformation. Finally, HSCN-Net adopted a hybrid loss function constituted by deformation field and image similarity to improve registration accuracy and generalization capability. In this work, 101 CT images of patients were collected for model construction (57), evaluation (14), and testing (30). HSCN-Net was compared with the classical Demons and VoxelMorph models. Qualitative analysis through the visual evaluation of critical brain tissues and quantitative analysis by determining the endpoint error (EPE) between the predicted sparse deformation vectors and gold-standard sparse deformation vectors, image normalized mutual information (NMI), and the Dice coefficient of the middle cerebral artery (MCA) blood supply area were carried out to assess model performance comprehensively. Results HSCN-Net and Demons had a better visual spatial matching performance than VoxelMorph, and HSCN-Net was more competent for smooth and large intersubject deformations than Demons. The mean EPE of HSCN-Net (3.29 mm) was less than that of Demons (3.47 mm) and VoxelMorph (5.12 mm); the mean Dice of HSCN-Net was 0.96, which was higher than that of Demons (0.90) and VoxelMorph (0.87); and the mean NMI of HSCN-Net (0.83) was slightly lower than that of Demons (0.84), but higher than that of VoxelMorph (0.81). Moreover, the mean registration time of HSCN-Net (17.86 s) was shorter than that of VoxelMorph (18.53 s) and Demons (147.21 s). Conclusion The proposed HSCN-Net could achieve accurate and rapid intersubject brain CT registration.

scholarly journals Impact of gender and age on inner diameter of arteries forming circle of Willis assessed by multidetector CT

2021 ◽  
Vol 2 (1) ◽  
pp. 37-41
Author(s):  
Prakash Sharma ◽  
Subita Lalchan ◽  
Subhash KC ◽  
Merina Gyawali ◽  
Niraj Kushwaha
Keyword(s):  
Cerebral Artery ◽  
Basilar Artery ◽  
Multidetector Ct ◽  
Circle Of Willis ◽  
Anterior Communicating Artery ◽  
Internal Diameter ◽  
Age Group ◽  
Technical Standards ◽  
Intracranial Arteries ◽  
The Brain

Introduction: The circle of Willis (CoW), which is located at the base of the brain is the most important anastomosis between the internal carotid and vertebral system. It is the main distributor of blood to the brain. Methods: CT head and CT angiography were performed using standard scan parameters. Only the tests with normal radiological reports and appropriate technical standards were included in the study. Component of circle of Willis: Anterior cerebral artery (ACA), Middle cerebral artery (MCA), Anterior communicating artery (Acom), Posterior Communicating artery (PCom), Basilar artery (BA) and Posterior cerebral artery (PCA) were identified and their internal diameter were measured. Results: Basilar artery was the artery with largest internal diameter with mean diameter of 2.5 ±0.52 mm. Men had significantly larger arterial sizes than women in all of the intracranial arteries examined except right PCom, Left PCom and right MCA. Right ACA had significantly larger internal diameter in <40 years’ age group. BA, left PCA, Bilateral PCom and MCA showed larger diameter in age group ≥40 years. Conclusion: Men had significantly larger arterial sizes than women in all of the intracranial arteries examined except right PCom, Left PCom and right MCA.

scholarly journals A Rare Anomaly in Circle of Willis

2013 ◽  
Vol 12 (1) ◽  
pp. 41-42
Author(s):  
Rishi Pokhrel ◽  
Rajan Bhatnagar
Keyword(s):  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Internal Carotid ◽  
Cerebral Arteries ◽  
Anterior Segment ◽  
Frontal Lobes ◽  
Circle Of Willis ◽  
Posterior Segment ◽  
Anterior Communicating Artery ◽  
Rare Anomaly

Anomalies in circle of Willis are very common and complete functioning ring as classically described is found only in 85 % of population. Most anomalies however are in posterior segment. We report a case of rare anomaly of anterior segment, where anterior communicating artery was completely absent and both anterior cerebral arteries arose from right internal carotid artery. Since both the frontal lobes of cerebrum are dependent upon right internal carotid artery for vascularization, with a poor communication with its left counterpart, ischemia or stroke in an event of pathological or iatrogenic compression of right internal carotid artery can occur.Medical Journal of Shree Birendra Hospital; January-June 2013/vol.12/Issue1/41-42DOI: http://dx.doi.org/10.3126/mjsbh.v12i1.9093          

scholarly journals An unusual variation in the anterior communicating artery of the circle of Willis in the human brain - a case report

2016 ◽  
Vol 05 (01) ◽  
pp. 039-043
Author(s):  
Farheen A Karim ◽  
J D Sarma ◽  
K L Talukdar
Keyword(s):  
Case Report ◽  
Surgical Treatment ◽  
Human Brain ◽  
Cerebral Artery ◽  
Anterior Cerebral Artery ◽  
Circle Of Willis ◽  
Anterior Communicating Artery ◽  
Interpeduncular Cistern ◽  
The Right ◽  
The Brain

AbstractThis report highlights an unusual variation of Anterior communicating artery of the circle of Willis found during dissection for studying circle of Willis. The brain was carefully extracted out of the skull so that arteries forming the circle of Willis do not get tom. The circle of Willis was identified in the interpeduncular cistern. Fine dissection was done to identify any variations. In this specimen there were double anterior communicating arteries joined in the midline by a short longitudinal segment of artery. Length and external diameters of both the Anterior communicating arteries were measured using Vernier calipers. Also, a medial striate artery (recurrent artery of Heubner) was seen originating from the right anterior cerebral artery just between the junctions of the proximal and distal Anterior communicating arteries with the right Anterior cerebral artery. Knowledge of this variation is valuable to neurosurgeons in planning surgical treatment and has clinical significance in relation to stroke.

Surgical anatomy of the proximal anterior cerebral artery

1976 ◽  
Vol 44 (3) ◽  
pp. 359-367 ◽  
Author(s):  
Ralph O. Dunker ◽  
A. Basil Harris
Keyword(s):  
Cerebral Artery ◽  
Anterior Cerebral Artery ◽  
Anterior Commissure ◽  
Cerebral Arteries ◽  
Internal Capsule ◽  
Carotid Bifurcation ◽  
Surgical Anatomy ◽  
Anterior Communicating Artery ◽  
Content Type ◽  
Posterior Limb

✓ The authors present this study of proximal anterior cerebral arteries in the normal human to provide a clearer basis for strategy in aneurysm surgery. They describe patterns of origin of branches, their subarachnoid course, and parenchymal distribution. Branches that originate from the anterior cerebral artery at the internal carotid bifurcation perfuse the genu and contiguous posterior limb of the internal capsule and the rostral thalamus. Proximal 4-mm branches supply the anterior limb of the internal capsule, the neighboring hypothalamus, anteroventral putamen, and pallidum. The remaining anterior cerebral artery proximal to the communicating artery sends branches to the optic chiasm, the adjacent hypothalamus, and the anterior commissure. Heubner's artery arises directly opposite the anterior communicating artery to supply much of the striatum and internal capsule rostral to the anterior commissure. The anterior communicating artery branches supply the fornix, corpus callosum, septal region, and anterior cingulum. The parenchymal distribution of these end arteries may be surmised from the site of origin of named vessels. With this anatomical information one can avoid interruption of blood supply to vital structures when dealing with the anterior cerebral artery and its branches.

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