keyword
MENU ▼
Read by QxMD icon Read
search

willis circle

keyword
https://www.readbyqxmd.com/read/29661071/a-comparison-of-image-quality-and-radiation-exposure-between-the-mini-c-arm-and-the-standard-c-arm
#1
Juliaan R M van Rappard, Willy A Hummel, Tijmen de Jong, Chantal M Mouës
BACKGROUND: The use of intraoperative fluoroscopy has become mandatory in osseous hand surgery. Due to its overall practicality, the mini C-arm has gained popularity among hand surgeons over the standard C-arm. This study compares image quality and radiation exposure for patient and staff between the mini C-arm and the standard C-arm, both with flat panel technology. METHODS: An observer-based subjective image quality study was performed using a contrast detail (CD) phantom...
April 1, 2018: Hand: Official Journal of the American Association for Hand Surgery
https://www.readbyqxmd.com/read/29650782/treatment-of-distal-anterior-cerebral-artery-aneurysms-with-flow-diverter-stents-a-single-center-experience
#2
F Cagnazzo, M Cappucci, C Dargazanli, P-H Lefevre, G Gascou, C Riquelme, A Bonafe, V Costalat
BACKGROUND AND PURPOSE: Flow diversion for aneurysms beyond the circle of Willis is still debated. Our aim was to evaluate the safety and efficacy of flow diversion treatment of distal anterior cerebral artery aneurysms. MATERIALS AND METHODS: Consecutive patients with distal anterior cerebral artery aneurysms treated from January 2014 to October 2017 were evaluated retrospectively with prospectively maintained data. Treatment was performed only for unruptured or recanalized aneurysms after coiling...
April 12, 2018: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/29616518/coronary-artery-bypass-surgery-in-patients-with-chronic-brain-hypoperfusion
#3
Hajime Imura, Yuji Maruyama, Kenichiro Takahashi, Dai Nishina, Takashi Nitta
BACKGROUND: Cerebrovascular disease (CVD) is a risk factor of stroke and cerebral hypoperfusion is one of the underlying mechanisms. We hypothesized that coronary artery bypass grafting (CABG) can be performed at an acceptable risk for such patients without concomitant surgery for CVD. METHODS: Carotid echo was carried out for 538 consecutive patients undergoing isolated CABG between 2005 and 2016. Magnetic resonance image/angiography (MRI/A) for neck and brain was performed for 288 patients (stenosis≥50% in echo were basically included)...
April 3, 2018: Journal of Cardiovascular Surgery
https://www.readbyqxmd.com/read/29600890/preoperative-brain-temperature-imaging-on-proton-magnetic-resonance-spectroscopy-predicts-hemispheric-ischemia-during-carotid-endarterectomy-for-unilateral-carotid-stenosis-with-inadequate-collateral-blood-flow
#4
Shouta Tsutsui, Takamasa Nanba, Yoshichika Yoshioka, Makoto Sasaki, Shunrou Fujiwara, Masakazu Kobayashi, Kenji Yoshida, Kenya Miyoshi, Shinpei Sato, Kuniaki Ogasawara
Objective Preoperative magnetic resonance (MR) angiography sometimes shows the absence of collateral flow via the circle of Willis. This study examined whether brain temperature (BT) imaging on multi-voxel proton MR spectroscopy after this finding increases the accuracy of predicting hemispheric ischemia during internal carotid artery (ICA) clamping during endarterectomy for patients with symptomatic unilateral carotid stenosis. Methods In 52 patients with ICA stenosis (≥70%) and absence of collateral blood flow via the circle of Willis on preoperative MR angiography, BT imaging was displayed using proton multi-voxel MR spectroscopy...
March 30, 2018: Neurological Research
https://www.readbyqxmd.com/read/29599169/aneurysmal-parent-artery-specific-inflow-conditions-for-complete-and-incomplete-circle-of-willis-configurations
#5
B M W Cornelissen, J J Schneiders, M E Sprengers, R van den Berg, P van Ooij, A J Nederveen, E van Bavel, W P Vandertop, C H Slump, H A Marquering, C B L M Majoie
BACKGROUND AND PURPOSE: Hemodynamics are thought to play a role in intracranial aneurysm growth and rupture. Computational fluid dynamics is frequently performed to assess intra-aneurysmal hemodynamics, using generalized flow waveforms of healthy volunteers as inflow boundary conditions. The purpose of this study was to assess differences in inflow conditions for different aneurysmal parent artery locations and variations of circle of Willis configurations. MATERIALS AND METHODS: In a series of 96 patients with 103 aneurysms, velocity measurements were acquired using 2D phase-contrast MR imaging perpendicular to the aneurysmal parent arteries in the circle of Willis...
March 29, 2018: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/29589286/genetic-and-environmental-contributions-to-variation-in-the-posterior-communicating-collaterals-of-the-circle-of-willis
#6
James E Faber, Hua Zhang, Wojciech Rzechorzek, Kathy Z Dai, Benjamin T Summers, Cooper Blazek, Samuel J Hedges
Variation in blood flow mediated by the posterior communicating collateral arteries (PComs) contributes to variation in the severity of tissue injury in obstructive disease. Evidence in animals and humans indicates that differences in the extent of PComs, i.e., their anatomic lumen diameter and whether they are present bilaterally, unilaterally, or absent, are a major factor. These differences arise during development since they are present at birth. However, the causal mechanisms are unknown. We used angiography after maximal dilation to examine involvement of genetic, environmental, and stochastic factors...
March 27, 2018: Translational Stroke Research
https://www.readbyqxmd.com/read/29578465/fluid-structure-interaction-of-patient-specific-circle-of-willis-with-aneurysm-investigation-of-hemodynamic-parameters
#7
Mahsa Jahed, Farzan Ghalichi, Mehdi Farhoudi
BACKGROUND: Circle of Willis (COW) is a network of cerebral artery which continually supplies the brain with blood. Any disturbance in this supply will result in trauma or even death. One of these damages is known as brain Aneurysm. Clinical methods for diagnosing aneurysm can only measure blood velocity; while, in order to understand the causes of these occurrences it is necessary to have information about the amount of pressure and wall shear stress, which is possible through computational models...
2018: Bio-medical Materials and Engineering
https://www.readbyqxmd.com/read/29530689/circle-of-willis-collateral-flow-in-carotid-artery-occlusion-is-depicted-by-4d-cta
#8
Midas Meijs, Frank-Erik de Leeuw, Hieronymus D Boogaarts, Rashindra Manniesing, Frederick Jan Anton Meijer
BACKGROUND: In case of carotid artery occlusion, the risk and extent of ischemic cerebral damage is highly dependent on the pathways of collateral flow, including the anatomy of the circle of Willis. In this report, cases are presented to illustrate that 4D-CTA can be considered as a non-invasive alternative to DSA for the evaluation of circle of Willis collateral flow. CASE DESCRIPTION: Five patients with unilateral internal carotid artery (ICA) occlusion underwent 4D-CTA for the evaluation of intracranial hemodynamics...
March 9, 2018: World Neurosurgery
https://www.readbyqxmd.com/read/29515376/cerebral-artery-diameter-in-inbred-mice-varies-as-a-function-of-strain
#9
Baogang Qian, Robert F Rudy, Tianxi Cai, Rose Du
Many strains of mice are utilized in mouse models of cerebrovascular diseases. Variations in vascular anatomy between these strains has been documented and may influence the phenotype in stroke models. To address inter-strain variations in the circle of Willis anatomy, the diameters of internal carotid, posterior communicating, anterior cerebral, and middle cerebral arteries in 144 mice from 32 inbred strains were measured. Arterial diameters were analyzed as a function of animal weight, age, and strain. Variations in the structure of the circle of Willis across strains were observed and noted...
2018: Frontiers in Neuroanatomy
https://www.readbyqxmd.com/read/29492574/autoregulating-cerebral-tissue-selfishly-exploits-collateral-flow-routes-through-the-circle-of-willis
#10
Flora A Kennedy McConnell, Stephen J Payne
OBJECTIVE: Ischemic stroke is a leading cause of death and disability. Autoregulation and collateral blood flow through the circle of Willis both play a role in preventing tissue infarction. A steady-state model of the cerebral arterial network was used to investigate the interaction of these mechanisms when autoregulation is impaired ipsilateral to an occluded artery. MATERIALS AND METHODS: Twelve structural variants of the circle of Willis were modelled with left internal carotid artery occlusion and coupled with (1) a passive model of the cerebral vascular bed, (2) a steady-state model of an autoregulating cerebral vascular bed, and (3) a model in which the contralateral hemisphere autoregulates and the ipsilateral hemisphere does not...
2018: Acta Neurochirurgica. Supplement
https://www.readbyqxmd.com/read/29484629/the-geometry-of-the-circle-of-willis-anatomical-variants-as-a-potential-cerebrovascular-risk-factor
#11
Raluca Pascalau, Vlad Adrian Padurean, Dana BARTOș, Adrian BARTOș, Bianca Aurora Szabo
AIM: Anatomical variants of the circle of Willis are diverse and frequent and, although they are not a direct cause of cerebrovascular diseases, they are risk factors for impaired collateral perfusion and wall shear stress. This study aimed to correlate the anatomical variants with their effects on the hemodynamic and geometrical parameters responsible for the pathogenesis of neurological diseases. MATERIAL AND METHODS: The circle of Willis and the proximal segments of the main arteries were dissected and measured on ten formalin-fixed human brains...
February 7, 2018: Turkish Neurosurgery
https://www.readbyqxmd.com/read/29479090/mra-based-evaluation-of-anatomical-variation-of-circle-of-willis-in-adult-pakistanis
#12
Rehana Shaikh, Saba Sohail
OBJECTIVE: To determine the frequency and patterns of normal anatomical variation of Circle of Willis on magnetic resonance angiogram in adults without cerebrovascular disease. METHODS: This descriptive cross-sectional study was conducted at the Radiology Department of Dow University of Health Sciences / Civil Hospital, Karachi, from January to December 2016, and comprised patients referred for magnetic resonance imaging of the brain and magnetic resonance angiogram without any clinical or radiological manifestation of cerebrovascular disease, primarily including those with suspected demyelination, infection, epilepsy or metastases...
February 2018: JPMA. the Journal of the Pakistan Medical Association
https://www.readbyqxmd.com/read/29457875/variations-of-the-circle-of-willis-at-the-end-of-the-human-embryonic-period
#13
Kana Furuichi, Aoi Ishikawa, Chigako Uwabe, Haruyuki Makishima, Shigehito Yamada, Tetsuya Takakuwa
Variations of the circle of Willis (CW) influence blood supply to the brain and adjacent structures in adults. We examined the formation of the CW in 20 human embryo samples at the end of the embryonic period using 3-D reconstructions of serial histological sections. The CW was closed in all samples, and did not form in a single plane, but was composed of multiple stair-like planes. The artery acutely curved at the caudal part of the CW, namely at the inlet of the basilar artery and bifurcation of the P1 segment of the posterior cerebral artery (PCA), reflecting flexure of the mesencephalon and diencephalon at this stage...
February 19, 2018: Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology
https://www.readbyqxmd.com/read/29434687/is-fetal-type-posterior-cerebral-artery-a-risk-factor-for-intracranial-aneurysm-as-analyzed-by-multislice-ct-angiography
#14
Zhen He, Yeda Wan
Fetal-type posterior cerebral artery (FTP) is a common anatomic variation that is closely associated with intracranial aneurysm. In the present study, multislice computed tomography angiography (CTA) was performed to assess whether FTP is a risk factor for intracranial aneurysm. CTA data of 364 consecutive cases of patients who were suspected with cerebrovascular disease or intracranial aneurysm of intracranial artery from 2013 to 2016 were reviewed and the incidence rates of FTP, other variations of the circle of Willis, intracranial aneurysm and FTP with intracranial aneurysm were evaluated...
January 2018: Experimental and Therapeutic Medicine
https://www.readbyqxmd.com/read/29404259/tuberculum-meningioma-orbitopterional-approach
#15
Alexander Yang, Mohammed Aref, A Samy Youssef
This is a case of an extensive tuberculum sella meningioma involving the circle of Willis down to the basilar artery that presented with bilateral visual loss worse on the right than left side. A one-piece right orbitopterional approach along the worse eye was used to gain access to the three cranial fossae. The orbitotomy facilitates access to the midline structures and contralateral base of the tumor with minimal brain retraction. Tumor resection is initiated by first identifying the tumor capsule, followed by piecemeal debulking via ultrasonic aspiration...
February 2018: Journal of Neurological Surgery. Part B, Skull Base
https://www.readbyqxmd.com/read/29379567/rare-presentation-of-moyamoya-disease-with-sub-acute-presentation-in-iran
#16
Payam Sasannejad, Fateme Rezaei, Reza Bidaki, Ehsan Zarepur
Moyamoya disease is a chronic progressive vascular disease of brain characterized by bilateral stenosis or occlusion of the arteries around the circle of Willis with prominent arterial collateral circulation. We introduce here a patient with Moyamoya who was misdiagnosed. She was a 16-yr-old female from north east of Iran who complained left hemiparesis and was diagnosed Moyamoya disease by brain and cervical CT-Angiography. There was still great difficulty in the diagnosis of diffuse white matter lesions. The CT-Angiography showed bilateral internal carotid stenosis with "puff of smoke" collateralization arising from the circle of Willis, therefore Moyamoya disease was raised...
2018: Iranian Journal of Child Neurology
https://www.readbyqxmd.com/read/29377946/heritability-of-circle-of-willis-variations-in-families-with-intracranial-aneurysms
#17
Mayte Sánchez van Kammen, Charles J Moomaw, Irene C van der Schaaf, Robert D Brown, Daniel Woo, Joseph P Broderick, Jason S Mackey, Gabriël J E Rinkel, John Huston, Ynte M Ruigrok
BACKGROUND: Intracranial aneurysms more often occur in the same arterial territory within families. Several aneurysm locations are associated with specific circle of Willis variations. We investigated whether the same circle of Willis variations are more likely to occur in first-degree relatives than in unrelated individuals. METHODS: We assessed four circle of Willis variations (classical, A1-asymmetry, incomplete posterior communicating artery and fetal circulation) in two independent groups of families with familial aneurysms and ≥2 first-degree relatives with circle of Willis imaging on MRA/CTA...
2018: PloS One
https://www.readbyqxmd.com/read/29373857/the-brain-willis-circle-and-ring-electric-power-systems-analogies-retrospectroscope
#18
Max E Valentinuzzi, Ricardo Diaz
The word analogy is a synonym of likeness, resemblance, similitude, or affinity and involves two concepts being placed side by side, as in a comparison [1]. The workings of nature and those of human societies are amenable to such analogous comparison-even though the evolution of the natural world obviously spans millions of years [2], while human societies are much younger, relatively puppies by comparison. This article considers two interesting examples from these two realms that show remarkable similarities (possibly a result of sheer chance), i...
January 2018: IEEE Pulse
https://www.readbyqxmd.com/read/29371256/comparison-of-blood-oxygenation-level-dependent-fmri-and-provocative-dsc-perfusion-mr-imaging-for-monitoring-cerebrovascular-reserve-in-intracranial-chronic-cerebrovascular-disease
#19
K R Thulborn, I C Atkinson, A Alexander, M Singal, S Amin-Hanjani, X Du, A Alaraj, F T Charbel
BACKGROUND AND PURPOSE: Loss of hemodynamic reserve in intracranial cerebrovascular disease reduces blood oxygenation level-dependent activation by fMRI and increases asymmetry in MTT measured by provocative DSC perfusion MR imaging before and after vasodilation with intravenous acetazolamide. The concordance for detecting hemodynamic reserve integrity has been compared. MATERIALS AND METHODS: Patients (n = 40) with intracranial cerebrovascular disease and technically adequate DSA, fMRI and provocative DSC perfusion studies were retrospectively grouped into single vessels proximal to and distal from the circle of Willis, multiple vessels, and Moyamoya disease...
January 25, 2018: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/29365098/safety-of-perioperative-cerebral-oxygen-saturation-during-debranching-in-patients-with-incomplete-circle-of-willis
#20
Yosuke Takahashi, Takashi Murakami, Yasuyuki Sasaki, Yasuyuki Bito, Hiromichi Fujii, Shinsuke Nishimura, Toshihiko Shibata
OBJECTIVES: The consequences of common carotid artery (CCA) cross-clamping during debranching before thoracic endovascular aortic repair are unclear. We examined the safety of a simple CCA cross-clamping procedure under regional cerebral oxygen saturation monitoring (rSO2) in patients with a complete or incomplete circle of Willis (CoW) anatomy. METHODS: Twenty-eight patients with thoracic aneurysm underwent elective debranching thoracic endovascular aortic repair with bilateral frontal rSO2 monitoring at our institution between January 2012 and October 2015...
January 19, 2018: Interactive Cardiovascular and Thoracic Surgery
keyword
keyword
104667
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"