scholarly journals Normal Variants of the Circle of Willis in patients undergoing CT Angiography

2017 ◽  
Vol 13 (1) ◽  
pp. 190-192 ◽  
Author(s):  
V Natraj Prasad ◽  
Pramod Kumar Chhetri ◽  
Arun Paudel
Keyword(s):  
Ct Angiography ◽  
Maximum Intensity Projection ◽  
Circle Of Willis ◽  
Ct Scanner ◽  
Anterior Portion ◽  
Posterior Portion ◽  
Source Data ◽  
3D Volume ◽  
The Brain ◽  
3D Volume Rendering

Background & Objectives: The Circle of Willis represents the important anastomotic cerebral vessels at the base of the brain. Variation in the Circle of Willis is common. A complete or normal Circle of Willis varies widely in the literature. As no prior data on the variations of Circle of Willis is available on Nepalese population, this study was undertaken in patients undergoing CT Angiography.Materials & Methods: During the period July 2016 till Dec 2016, 65 patients who were referred for brain CT Angiography (Toshiba Aquilion Prime 160 slice Multi Detector CT scanner) from medicine, neurology and neuro-surgery were included in the study. CT scans were taken from the base of skull to the vertex. In addition to the axial source data, post-processed multiplanar reformatted (MPR), maximum-intensity projection (MIP), and 3D volume-rendering (VR) images were evaluated. Results: Of the 65 patients who underwent CT Angiography a normal or complete Circle of Willis was seen in only 35.4 % (23 patients). The most common variant of the Circle of Willis was a hypoplastic Pcom seen in 26.2 % (17 patients). This was followed by fetal origin of PCA seen in 13.8 % (9 patients). An absent Pcom and hypoplastic / absent Acom was in 12.3 % each (8 patients each). Conclusion: Variation in the Circle of Willis is common. Variations in the posterior portion of the Circle of Willis are more common than the anterior portion.

scholarly journals Clinical importance and configuration of collateral vessel systems in patients with Takayasu arteritis or with thymoma visualized by three-dimensional volume rendering computed tomographic angiography

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
N Funabashi ◽  
Y Kobayashi
Keyword(s):  
Ct Angiography ◽  
Volume Rendering ◽  
Takayasu Arteritis ◽  
Three Dimensional ◽  
Clinical Importance ◽  
Venous System ◽  
Collateral Arteries ◽  
Iodinated Contrast ◽  
3D Volume ◽  
3D Volume Rendering

Abstract Background Collateral vessels form after gradual blood vessel occlusion. We speculate that in Takayasu arteritis (TA) and thymoma patients, before planning surgical procedures, a complex artery/venous system should be examined using three dimensional (3D) volume rendering computed tomographic (CT) angiography. Purpose To seek the clinical importance and actual complex configuration of collateral vessel systems in patients with TA or with thymoma using 3D volume rendering CT angiography with special acquisition method. Methods We performed 3D CT angiography in patients with Takayasu arteritis (TA) with occluded arteries (N=6) or thymoma (N=2) with occluded superior-vena-cava (SVC), respectively. For CT angiography in thymoma patients, diluted (1/4) iodinated-contrast was injected in right and left medial cubital-veins simultaneously, and images acquired 10 seconds after contrast-injection. Results Occluded and collateral-arteries (TA group) and occluded SVC and collateral-veins (thymoma group) were successfully visualized (Figures a-h). Collateral-arteries form from the inferior mesenteric artery (Figure a) or de novo arteries from the abdominal aorta (Figure b) after superior mesenteric artery occlusion (Figure c, d). In patients with thymoma, an SVC thymoma disrupts venous return in the neck and upper extremities; a complex venous system forms on the abdominal surface (Figure e-h). Conclusion In TA and thymoma patients, before planning surgical procedures, a complex artery/venous system should be examined using 3D volume rendering CT angiography. For CT in thymoma, diluted (1/4) iodinated contrast should be injected in both medial cubital veins, and images should be acquired 10 seconds after contrast-injection. 3D volume rendering CT angiography Funding Acknowledgement Type of funding source: None

scholarly journals Brain network dynamics during spontaneous strategy shifts and incremental task optimization

2018 ◽  
Author(s):  
Michele Allegra ◽  
Shima Seyed-Allaei ◽  
Nicolas W. Schuck ◽  
Daniele Amati ◽  
Alessandro Laio ◽  
...  
Keyword(s):  
Spatial Information ◽  
Brain Network ◽  
Angular Gyrus ◽  
Default Network ◽  
Perceptual Decision Making ◽  
Anterior Portion ◽  
Posterior Portion ◽  
Local Coherence ◽  
New Strategy ◽  
The Brain

AbstractWith practice, humans may improve their performance in a task by either optimizing a known strategy or discovering a novel, potentially more fruitful strategy. How does the brain support these two fundamental abilities? In the present experiment, subjects performed a simple perceptual decision-making task. They could either use and progressively optimize an instructed strategy based on stimulus position, or spontaneously devise and then use a new strategy based on stimulus color. We investigated how local and long-range BOLD coherence behave during these two types of strategy learning by applying a recently developed unsupervised fMRI analysis technique that was specifically designed to probe the presence of transient correlations. Converging evidence showed that the posterior portion of the default network, i.e. the precuneus and the angular gyrus bilaterally, has a central role in the optimization of the current strategy: these regions encoded the relevant spatial information, increased the level of local coherence and the strength of connectivity with other relevant regions in the brain (e.g. visual cortex, dorsal attention network). This increase was proportional to the task optimization achieved by subjects, as measured by the reduction of reaction times, and was transiently disrupted when subjects were forced to change strategy. By contrast, the anterior portion of the default network (i.e. medial prefrontal cortex) together with rostral portion of the fronto-parietal network showed an increase in local coherence and connectivity only in subjects that would at some point spontaneously choose the new strategy. Overall, our findings shed light on the dynamic interactions between regions related with attention and with cognitive control, underlying the balance between strategy exploration and exploitation. Results suggest that the default network, far from being “shut-down” during task performance, has a pivotal role in the background exploration and monitoring of potential alternative courses of action.

A spontán mellkasfali sérvekről két operált eset kapcsán

2010 ◽  
Vol 63 (2) ◽  
pp. 80-83 ◽  
Author(s):  
Károly Vincze ◽  
Péter Zádori ◽  
Zsolt Magyaródi ◽  
Gyula Horváth
Keyword(s):  
Volume Rendering ◽  
Spiral Ct ◽  
Multislice Spiral Ct ◽  
3D Volume ◽  
3D Volume Rendering

Absztrakt A szerzők a világirodalmi ritkaságnak számító atraumaticus (spontán) mellkasfali tüdősérvet ismertetik. Két operált betegük kapcsán bemutatják a sérv kialakulását elősegítő körülményeket és a kórkép klinikai jellemzőit. Mindkét betegük spontán mellkasfali (intercostalis) sérvét chronicus obstructiv syndroma (COPD) okozta makacs köhögés váltotta ki. Az elvégzett multislice spirál CT (MSCT) vizsgálat, valamint a speciális szoftver segítségével készített másodlagos 3D „volume-rendering” (VRT) rekonstrukciós képek egyértelműen utaltak a ritka kórformára. Az MSCT-vizsgálatok a Kaposi Mór Oktató Kórházban készültek, Siemens Somatom Emotion 6 MSCT-berendezéssel. A pontos diagnózis birtokában végzett mellkasfali korrekciók tartós gyógyuláshoz vezettek. A szerzők röviden ismertetik a mellkasfali sérvekkel kapcsolatos hazai és fontosabb külföldi irodalmi vonatkozásokat. A kórkép rendkívüli ritkasága ellenére a kialakulásában szerepet játszó COPD elterjedtsége miatt érdemel figyelmet. A hasonló esetek diagnosztikájában nagy segítséget jelenthet a bemutatott korszerű képalkotó eljárás alkalmazása.

scholarly journals Interactive 3D volume rendering in biomedical publications

Micron ◽  
2010 ◽  
Vol 41 (7) ◽  
pp. 886.e1-886.e17 ◽  
Author(s):  
Bernhard Ruthensteiner ◽  
Natalie Baeumler ◽  
David G. Barnes
Keyword(s):  
Volume Rendering ◽  
Interactive 3D ◽  
Biomedical Publications ◽  
3D Volume ◽  
3D Volume Rendering

Hyperthermia catheter implantation and therapy in the brain

1990 ◽  
Vol 72 (6) ◽  
pp. 975-979 ◽  
Author(s):  
J. Alexander Marchosky ◽  
Christopher J. Moran ◽  
Neal E. Fearnot ◽  
Charles F. Babbs
Keyword(s):  
Computerized Tomography ◽  
Malignant Gliomas ◽  
Twist Drill ◽  
Ct Scanner ◽  
Tumor Blood Flow ◽  
Content Type ◽  
Catheter Implantation ◽  
Computer Controlled ◽  
Drill Holes ◽  
The Brain

✓ For the treatment of malignant gliomas, a technique for implanting hyperthermia catheters was developed that utilized a stereotactic template and head-stabilization frame mounted on a computerized tomography (CT) scanner. Computerized tomography scans were used to measure tumor dimensions and to determine the number, implantation depths, and active heating lengths of the catheters, which were implanted through twist-drill holes while the patient was in the CT room. Heat was subsequently delivered via implanted catheters using a computer-controlled hyperthermia system, which partially compensates for heterogeneous and time-varying tumor blood flow.

‘To unlock the secret places of Man’s Mind’.1 Thomas Willis (1621–1675)

2021 ◽  
pp. 096777202110007
Author(s):  
Penelope Hunting
Keyword(s):  
Medical Practice ◽  
Natural Philosophy ◽  
Circle Of Willis ◽  
High Street ◽  
The Brain

Thomas Willis was born four hundred years ago on 27 January 1621 in Wiltshire. He has been dubbed ‘the father of neurology’ and is remembered for the Circle of Willis at the base of the brain. Young Thomas was educated at Oxford as a schoolboy and undergraduate. From 1646 he practised medicine and studied chemistry; he joined the Oxford Experimental Philosophical Club, and was Sedleian Professor of Natural Philosophy from 1660. He established a prosperous medical practice at The Angel on Oxford High Street, and achieved international acclaim for Cerebri anatome (1664). Lured to London in 1667, Willis lived in style but attended the sick poor on Sundays and worshipped twice daily at St Martin-in-the-Fields.

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