Three-Dimensional Computed Tomographic Reconstructions of Intracranial Meningiomas

Neurosurgery ◽  
1988 ◽  
Vol 23 (5) ◽  
pp. 570-575 ◽  
Author(s):  
David J. Chalif ◽  
Craig R. Dufresne ◽  
Joseph Ransohoff ◽  
Joseph A. McCarthy
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Computer Software ◽  
Computed Tomographic ◽  
Intracranial Meningiomas ◽  
Three Dimensional Images ◽  
Ct Data ◽  
Surgical Adjunct ◽  
Relationship Of ◽  
The Relationship

Abstract In a series of four patients with intracranial meningiomas, three-dimensional computed tomographic (CT) reconstructions were a useful diagnostic and surgical adjunct. Three-dimensional images are created from standard CT data by a boundary-detecting computer software program. Three-dimensional images of tumor invading or adjacent to the bony calvarium are projected about the x, y, and z axes. Axial and sagittal sections delineate the lesions. The images created allow a surgical view of the meningiomas in three-dimensional space and demonstrate the relationship of these masses to the skull. The use of three-dimensional reconstructions in craniofacial surgery and in neurosurgery is reviewed.

A Research on the Morphology and Composition of Flocs (Part 1: Floc Breaage Disregarded)

2013 ◽  
Vol 726-731 ◽  
pp. 1566-1572 ◽  
Author(s):  
Shi Qiang Ding ◽  
Qing Na Li ◽  
Xin Rong Pang ◽  
Ji Run Xu
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
New Classification ◽  
Suspension Viscosity ◽  
Primary Particles ◽  
Long Time ◽  
Relationship Of ◽  
The Relationship ◽  
Three Dimensional Space ◽  
Floc Breakage

The characteristics of flocs aggregated in flocculation have been paid more and more attention for a long time. In this paper, a new classification and analyses method dealing with the flocs is developed. The flocs formed after flocculation is divided into four kinds, including the left primary particles, linear flocs with all component particles in a line, planar flocs with all component particles on a plane and volumetric flocs with all component particles in a three-dimensional space. By analyzing the formation approaches of different kind of flocs regardless of the floc breakage, the number of every kind of floc is analyzed to be related with the suspension concentration mathematically. After comparing the different items in the models describing the relationship of floc number and concentration, a series of simplified expressions are presented. Lastly, a mathematical equation relating the measurable suspension viscosity with the numbers of different flocs is obtained.

Graphical representation of stereochemical configuration (IUPAC Recommendations 2006)

2006 ◽  
Vol 78 (10) ◽  
pp. 1897-1970 ◽  
Author(s):  
Jonathan Brecher
Keyword(s):  
Graphical Representation ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Wide Audience ◽  
Stereochemical Configuration ◽  
Stereogenic Centers ◽  
Relationship Of ◽  
Stereogenic Center ◽  
The Relationship

Stereochemical configuration is determined by the relationship of atoms in three-dimensional space, yet remains most commonly represented in two-dimensional media such as printed publications or computer screens. Recommendations are provided for the display of three-dimensional stereochemical information in two-dimensional diagrams in ways that avoid ambiguity and are likely to be understood correctly by all viewers. Examples are provided for all types of stereochemical configuration, with explanation of which styles are preferred and which should be avoided. Principal recommendations include:Know your audience: Diagrams that have a wide audience should be drawn as simply as possible.Avoid ambiguous drawing styles.Avoid the use of perspective diagrams and class-specific drawing styles (Fischer projections, Haworth projections, etc.) when structures are to be interpreted by computers.Use solid wedges to indicate bonds that project above the plane of the paper and hashed wedges to indicate bonds that project below the plane of the paper; in both cases, the bonds must be oriented with the narrow end at the stereogenic center.Avoid connecting stereogenic centers with a stereobond.

Utility of Three-dimensional Computed Tomographic Angiography for Assessment of Relationships between the Vertebrobasilar System and the Cranial Base

Neurosurgery ◽  
2001 ◽  
Vol 48 (2) ◽  
pp. 318-327 ◽  
Author(s):  
Alan T. Villavicencio ◽  
Linda Gray ◽  
Jean-Christophe Leveque ◽  
Takanori Fukushima ◽  
Sohaib Kureshi ◽  
...  
Keyword(s):  
Basilar Artery ◽  
Three Dimensional ◽  
Cranial Base ◽  
Computed Tomographic Angiography ◽  
Conventional Angiography ◽  
Computed Tomographic ◽  
Vertebrobasilar System ◽  
Tomographic Angiography ◽  
Relationship Of ◽  
The Relationship

Abstract OBJECTIVE The optimal surgical exposure for basilar tip aneurysms is dictated by the relationship of the basilar bifurcation to the cranial base. This study was designed to evaluate three-dimensional computed tomographic angiography as a means of obtaining detailed anatomic information on the basilar artery and the surrounding cranial base in individual patients before surgery. METHODS We studied 30 patients using three-dimensional computed tomographic angiographic reconstructions from 1-mm computed tomographic slices. Detailed anatomic measurements were performed to define the relationship between the basilar artery and the cranial base. Particular attention was paid to the height of the dorsum sellae and its relationship to the basilar bifurcation. RESULTS The heights of the basilar apex and the vertebrobasilar junction, relative to the cranial base, were extremely variable. Considerable asymmetries in the heights of the left and right posterior clinoid processes were identified; in one case, this difference was more than 1 cm (mean difference in height, 0.9 mm; range, 0–10.3 mm). The heights of the posterior clinoid processes above the sellar floor ranged from 5.8 to 14.1 mm (mean height, 9.5 mm). We were able to determine the feasibility of the pterional/orbitozygomatic, middle fossa/anterior petrosal, and presigmoid retrolabyrinthine approaches to an individual basilar bifurcation. We also estimated the amount of bone removal required and determined the operative distances via those approaches. CONCLUSION Three-dimensional computed tomographic angiography is a useful tool for assessing critical anatomic relationships and represents an adjunct to conventional angiography in the planning of individualized, precisely tailored, cranial base approaches to the vertebrobasilar system.

Considerations for Post-processing Parameters in Mixed-Method 3D Analyses

2021 ◽  
Vol 9 (4) ◽  
pp. 325-337
Author(s):  
Robert Z. Selden ◽  
Lauren N. Butaric ◽  
Kersten Bergstrom ◽  
Dennis Van Gerven
Keyword(s):  
Three Dimensional ◽  
Processing Parameters ◽  
Surface Model ◽  
Digital Repositories ◽  
Computed Tomographic ◽  
Archaeological Data ◽  
3D Data ◽  
Morphometric Analyses ◽  
Smoothing Parameters ◽  
Ct Data

ABSTRACTThe production of three-dimensional (3D) digital meshes of surface and computed tomographic (CT) data has become widespread in morphometric analyses of anthropological and archaeological data. Given that processing methods are not standardized, this leaves questions regarding the comparability of processed and digitally curated 3D datasets. The goal of this study was to identify those processing parameters that result in the most consistent fit between CT-derived meshes and a 3D surface model of the same human mandible. Eight meshes, each using unique thresholding and smoothing parameters, were compared to assess whole-object deviations, deviations along curves, and deviations between specific anatomical features on the surface model when compared with the CT scans using a suite of comparison points. Based on calculated gap distances, the mesh that thresholded at “0” with an applied smoothing technique was found to deviate least from the surface model, although it is not the most biologically accurate. Results have implications for aggregated studies that employ multimodal 3D datasets, and caution is recommended for studies that enlist 3D data from websites and digital repositories, particularly if processing parameters are unknown or derived for studies with different research foci.

scholarly journals Heart Rate Dependency and Inter-Lead Variability of the T Peak – T End Intervals

2020 ◽  
Vol 11 ◽  
Author(s):  
Irena Andršová ◽  
Katerina Hnatkova ◽  
Martina Šišáková ◽  
Ondřej Toman ◽  
Peter Smetana ◽  
...  
Keyword(s):  
Heart Rate ◽  
Three Dimensional ◽  
Rate Dependency ◽  
Rate Dependent ◽  
Heart Rate Correction ◽  
Ecg Leads ◽  
Relationship Of ◽  
The Relationship ◽  
Vector Magnitude

The electrocardiographic (ECG) assessment of the T peak–T end (Tpe) intervals has been used in many clinical studies, but several related physiological aspects have not been reported. Specifically, the sources of the Tpe differences between different ECG leads have not been systematically researched, the relationship of Tpe duration to underlying heart rate has not been firmly established, and little is known about the mutual correspondence of Tpe intervals measured in different ECG leads. This study evaluated 796,620 10-s 12-lead ECGs obtained from long-term Holters recorded in 639 healthy subjects (311 female) aged 33.8 ± 9.4 years. For each ECG, transformation to orthogonal XYZ lead was used to measure Tpe in the orthogonal vector magnitude (used as a reference for lead-to-lead comparisons) and to construct a three-dimensional T wave loop. The loop roundness was expressed by a ratio between its circumference and length. These ratios were significantly related to the standard deviation of Tpe durations in different ECG leads. At the underlying heart rate of 60 beats per minute, Tpe intervals were shorter in female than in male individuals (82.5 ± 5.6 vs 90.0 ± 6.5 ms, p < 0.0001). When studying linear slopes between Tpe intervals measured in different leads and the underlying heart rate, we found only minimal heart rate dependency, which was not systematic across the ECG leads and/or across the population. For any ECG lead, positive Tpe/RR slope was found in some subjects (e.g., 79 and 25% of subjects for V2 and V4 measurements, respectively) and a negative Tpe/RR slope in other subjects (e.g., 40 and 65% for V6 and V5, respectively). The steepest positive and negative Tpe/RR slopes were found for measurements in lead V2 and V4, respectively. In all leads, the Tpe/RR slope values were close to zero, indicating, on average, Tpe changes well below 2 ms for RR interval changes of 100 ms. On average, longest Tpe intervals were measured in lead V2, the shortest in lead III. The study concludes that the Tpe intervals measured in different leads cannot be combined. Irrespective of the measured ECG lead, the Tpe interval is not systematically heart rate dependent, and no heart rate correction should be used in clinical Tpe investigations.

scholarly journals HUBUNGAN INDEKSMASSA TUBUH DAN LINGKAR PINGGANG DENGAN TEKANAN DARAH LAKI-LAKI DEWASA

2018 ◽  
Vol 9 (2) ◽  
pp. 193-199
Author(s):  
Tamariani Manullang
Keyword(s):  
Blood Pressure ◽  
Waist Circumference ◽  
Systolic Blood Pressure ◽  
Study Design ◽  
Computer Software ◽  
Adult Males ◽  
Cross Sectional ◽  
Relationship Of ◽  
The Relationship

Prevalence of hypertension in adult males was highest in PuskesmasBasuki Rahmat (16.2%) as many as 648 cases of hypertension patients which hasincreased compared to 2012 by 12% in cases of hypertension totaled 482 patients((Dinkes Kota, 2013). This study aims to determine the relationship of body massindex (BMI) and waist circumference (WC) with systolic blood pressure (BP) in adultmales in Puskesmas Basuki Rahmat Bengkulu City in 2015. The study design wasdescriptive analytic with cross sectional approach. Study location was in PuskesmasBasuki Rahmat City of Bengkulu. Samples were selected using purposive samplingtotalling 68 people. Criterias sample were being adult males who occupied inPuskesmas Basuki Rahmat City of Bengkulu, aged ≥ 18 years, agreed to beinterviewed,and able to communicate actively. Data were obtained include BMI, WCand systolic BP adult males and processed using computer software with pearsoncorrelation analysis.The results showed that there was relationship between BMI andsystolic BP (p = 0.0005; r = 0.395); between WC and systolic BP (p = 0.004 and r =0.347) in adult males. This study concluded that there was relationship between BMIand WC with systolic BP in adult males in Puskesmas Basuki Rahmat Bengkulu Cityin 2015.

Aerodynamic Characteristics Analysis of High-Speed Train on Cutting under Crosswinds

2013 ◽  
Vol 300-301 ◽  
pp. 62-67
Author(s):  
Kun Ye ◽  
Ren Xian Li
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
High Speed Train ◽  
Aerodynamic Forces ◽  
Cutting Depth ◽  
Cutting Slope ◽  
Characteristics Analysis ◽  
Relationship Of ◽  
The Relationship

Cutting is an effective device to reduce crosswind loads acting on trains. The cutting depth, width and gradient of slope are important factors for design and construction of cutting. Based on numerical analysis methods of three-dimensional viscous incompressible aerodynamics equations, aerodynamic side forces and yawing moments acting on the high-speed train, with different depths and widths of cutting，are calculated and analyzed under crosswinds，meanwhile the relationship of the gradient of cutting slope and transverse aerodynamic forces acting on trains are also studied. Simulation results show that aerodynamic side forces and yawing moments acting on the train（the first, middle and rear train）decrease with the increase of cutting depth. The relationship between transverse forces (moments) coefficients acting on the three sections and the cutting depth basically is the three cubed relation. The bigger is cutting width，the worse is running stability of train. The relationship between yawing moments coefficients acting each body of the train and the cutting width approximately is the three cubed relation. The transverse Aerodynamic forces decreased gradually with the increase of the gradient of cutting slope, the relationship between yawing moments coefficients acting each body of the train and the gradient of cutting slope basically is the four cubed relation.

scholarly journals The relationship between diversity and productivity from a three-dimensional space view in a natural mesotrophic lake

2021 ◽  
Vol 121 ◽  
pp. 107069
Author(s):  
Ai-Ping Wu ◽  
Shi-Yun Ye ◽  
Jin-Rui Yuan ◽  
Liang-Yu Qi ◽  
Zheng-Wu Cai ◽  
...  
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Mesotrophic Lake ◽  
The Relationship ◽  
Three Dimensional Space
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