Knowledge Based Automated Boundary Detection for Qualifying of LV Function in Low Contrast Angiographic Images

2000 ◽  
Vol 4 (2) ◽  
pp. 171-176
Author(s):  
Yang Hee Yee ◽  
◽  
Chun Kee Jeon ◽  
Sang-Rok Oh ◽  
Mignon-Park ◽  
...  
Keyword(s):  
Left Ventricle ◽  
Cardiac Function ◽  
Shape Change ◽  
A Priori ◽  
Boundary Detection ◽  
Lv Function ◽  
Shape Information ◽  
Detection Scheme ◽  
Low Contrast ◽  
Knowledge Based

A Cardiac function is evaluated quantitatively by analyzing a shape change of the heart wall boundaries in angiographic images. To begin with, a boundary detection of end systolic left ventricle (ESLV) and end diastolic left ventricle (EDLV) is essential for the quantitative analysis of the cardiac function. Conventional methods for the boundary detection are almost semi-automatic, and a knowledgeable human operator’s intervention is still required. Manual tracing of the boundaries is currently used for subsequent analysis and diagnosis. However, these methods do not cut excessive time, labor, and subjectivity associated with manual intervention by a human operator. Generally, EDLV images have noncontiguous and ambiguous edge signal on some boundary regions. In this paper, we propose a new method for an automated detection of left ventricle (LV) boundaries in noncontiguous and ambiguous EDLV images. The proposed boundary detection scheme is based on a priori knowledge information and is divided into two steps. The first step is to detect EDLV boundary using ESLV boundary. The second step is to correct the detected EDLV boundary using the left ventricle (LV) shape information. We compared the proposed method with the manual method to detect the EDLV boundary. And through the experiments of the proposed method, we verified the usefulness of this method.

scholarly journals Myocardial deformation in patients with a single left ventricle using 2D cardiovascular magnetic resonance feature tracking: a case–control study

2021 ◽  
Author(s):  
Fabian Strodka ◽  
Jana Logoteta ◽  
Roman Schuwerk ◽  
Mona Salehi Ravesh ◽  
Dominik Daniel Gabbert ◽  
...  
Keyword(s):  
Cardiovascular Magnetic Resonance ◽  
Magnetic Resonance ◽  
Left Ventricle ◽  
Feature Tracking ◽  
Systolic Function ◽  
Radial Strain ◽  
Left Ventricular ◽  
Lv Function ◽  
Significant Difference ◽  
Lv Volumes

AbstractVentricular dysfunction is a well-known complication in single ventricle patients in Fontan circulation. As studies exclusively examining patients with a single left ventricle (SLV) are sparse, we assessed left ventricular (LV) function in SLV patients by using 2D-cardiovascular magnetic resonance (CMR) feature tracking (2D-CMR-FT) and 2D-speckle tracking echocardiography (2D-STE). 54 SLV patients (11.4, 3.1–38.1 years) and 35 age-matched controls (12.3, 6.3–25.8 years) were included. LV global longitudinal, circumferential and radial strain (GLS, GCS, GRS) and strain rate (GLSR, GCSR, GRSR) were measured using 2D-CMR-FT. LV volumes, ejection fraction (LVEF) and mass were determined from short axis images. 2D-STE was applied in patients to measure peak systolic GLS and GLSR. In a subgroup analysis, we compared double inlet left ventricle (DILV) with tricuspid atresia (TA) patients. The population consisted of 19 DILV patients, 24 TA patients and 11 patients with diverse diagnoses. 52 patients were in NYHA class I and 2 patients were in class II. Most SLV patients had a normal systolic function but median LVEF in patients was lower compared to controls (55.6% vs. 61.2%, p = 0.0001). 2D-CMR-FT demonstrated reduced GLS, GCS and GCSR values in patients compared to controls. LVEF correlated with GS values in patients (p < 0.05). There was no significant difference between GLS values from 2D-CMR-FT and 2D-STE in the patient group. LVEF, LV volumes, GS and GSR (from 2D-CMR-FT) were not significantly different between DILV and TA patients. Although most SLV patients had a preserved EF derived by CMR, our results suggest that, LV deformation and function may behave differently in SLV patients compared to healthy subjects.

Effects of avertin versus xylazine-ketamine anesthesia on cardiac function in normal mice

2001 ◽  
Vol 281 (5) ◽  
pp. H1938-H1945 ◽  
Author(s):  
Chari Y. T. Hart ◽  
John C. Burnett ◽  
Margaret M. Redfield
Keyword(s):  
Cardiac Function ◽  
Diastolic Pressure ◽  
Systolic Function ◽  
Pressure Rise ◽  
Left Ventricular ◽  
Lv Function ◽  
Ketamine Anesthesia ◽  
The Difference ◽  
And Function ◽  
Derivatives Of

Anesthetic regimens commonly administered during studies that assess cardiac structure and function in mice are xylazine-ketamine (XK) and avertin (AV). While it is known that XK anesthesia produces more bradycardia in the mouse, the effects of XK and AV on cardiac function have not been compared. We anesthetized normal adult male Swiss Webster mice with XK or AV. Transthoracic echocardiography and closed-chest cardiac catheterization were performed to assess heart rate (HR), left ventricular (LV) dimensions at end diastole and end systole (LVDd and LVDs, respectively), fractional shortening (FS), LV end-diastolic pressure (LVEDP), the time constant of isovolumic relaxation (τ), and the first derivatives of LV pressure rise and fall (dP/d t max and dP/d t min, respectively). During echocardiography, HR was lower in XK than AV mice (250 ± 14 beats/min in XK vs. 453 ± 24 beats/min in AV, P < 0.05). Preload was increased in XK mice (LVDd: 4.1 ± 0.08 mm in XK vs. 3.8 ± 0.09 mm in AV, P < 0.05). FS, a load-dependent index of systolic function, was increased in XK mice (45 ± 1.2% in XK vs. 40 ± 0.8% in AV, P < 0.05). At LV catheterization, the difference in HR with AV (453 ± 24 beats/min) and XK (342 ± 30 beats/min, P < 0.05) anesthesia was more variable, and no significant differences in systolic or diastolic function were seen in the group as a whole. However, in XK mice with HR <300 beats/min, LVEDP was increased (28 ± 5 vs. 6.2 ± 2 mmHg in mice with HR >300 beats/min, P < 0.05), whereas systolic (LV dP/d t max: 4,402 ± 798 vs. 8,250 ± 415 mmHg/s in mice with HR >300 beats/min, P < 0.05) and diastolic (τ: 23 ± 2 vs. 14 ± 1 ms in mice with HR >300 beats/min, P < 0.05) function were impaired. Compared with AV, XK produces profound bradycardia with effects on loading conditions and ventricular function. The disparate findings at echocardiography and LV catheterization underscore the importance of comprehensive assessment of LV function in the mouse.

A priori knowledge based particle filter for estimating 3-D pose position of implanted knee

2010 ◽  
Author(s):  
Yusuke Nakajima ◽  
Syoji Kobashi ◽  
Yohei Tsumori ◽  
Nao Shibanuma ◽  
Fumiaki Imamura ◽  
...  
Keyword(s):  
Particle Filter ◽  
A Priori ◽  
A Priori Knowledge ◽  
Knowledge Based ◽  
Priori Knowledge

Necessity, Certainty, and the A Priori

1988 ◽  
Vol 18 (1) ◽  
pp. 43-66 ◽  
Author(s):  
Albert Casullo
Keyword(s):  
Cognitive Processes ◽  
Mathematical Knowledge ◽  
A Priori ◽  
Theory Of Knowledge ◽  
A Posteriori ◽  
Unitary Theory ◽  
Knowledge Based

Empiricist theories of knowledge are attractive for they offer the prospect of a unitary theory of knowledge based on relatively well understood physiological and cognitive processes. Mathematical knowledge, however, has been a traditional stumbling block for such theories. There are three primary features of mathematical knowledge which have led epistemologists to the conclusion that it cannot be accommodated within an empiricist framework: 1) mathematical propositions appear to be immune from empirical disconfirmation; 2) mathematical propositions appear to be known with certainty; and 3) mathematical propositions are necessary. Epistemologists who believe that some nonmathematical propositions, such as logical or ethical propositions, cannot be known a posteriori also typically appeal to the three factors cited above in defending their position. The primary purpose of this paper is to examine whether any of these alleged features of mathematical propositions establishes that knowledge of such propositions cannot be a posteriori.

Automated Three-Dimensional Reconstruction of the Left Ventricle From Multiple-Axis Echocardiography

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Navaneetha Krishnan Rajan ◽  
Zeying Song ◽  
Kenneth R. Hoffmann ◽  
Marek Belohlavek ◽  
Eileen M. McMahon ◽  
...  
Keyword(s):  
Left Ventricle ◽  
Cross Sections ◽  
Low Cost ◽  
Software Tool ◽  
Acquisition Time ◽  
Lv Function ◽  
High Temporal Resolution ◽  
Standard Format ◽  
Flow Simulations ◽  
Automated Method

Two-dimensional echocardiography (echo) is the method of choice for noninvasive evaluation of the left ventricle (LV) function owing to its low cost, fast acquisition time, and high temporal resolution. However, it only provides the LV boundaries in discrete 2D planes, and the 3D LV geometry needs to be reconstructed from those planes to quantify LV wall motion, acceleration, and strain, or to carry out flow simulations. An automated method is developed for the reconstruction of the 3D LV endocardial surface using echo from a few standard cross sections, in contrast with the previous work that has used a series of 2D scans in a linear or rotational manner for 3D reconstruction. The concept is based on a generalized approach so that the number or type (long-axis (LA) or short-axis (SA)) of sectional data is not constrained. The location of the cross sections is optimized to minimize the difference between the reconstructed and measured cross sections, and the reconstructed LV surface is meshed in a standard format. Temporal smoothing is implemented to smooth the motion of the LV and the flow rate. This software tool can be used with existing clinical 2D echo systems to reconstruct the 3D LV geometry and motion to quantify the regional akinesis/dyskinesis, 3D strain, acceleration, and velocities, or to be used in ventricular flow simulations.

A MULTILEVEL FUSION APPROACH TO OBJECT IDENTIFICATION IN OUTDOOR ROAD SCENES

1995 ◽  
Vol 09 (01) ◽  
pp. 23-65 ◽  
Author(s):  
VITTORIO MURINO ◽  
CARLO S. REGAZZONI ◽  
GIAN LUCA FORESTI ◽  
GIANNI VERNAZZA
Keyword(s):  
Data Integration ◽  
Environmental Conditions ◽  
Autonomous Vehicle ◽  
A Priori ◽  
Object Identification ◽  
Distributed Knowledge ◽  
Knowledge Based ◽  
Multilevel Fusion ◽  
Fusion Framework ◽  
Fusion Approach

The task of object identification is fundamental to the operations of an autonomous vehicle. It can be accomplished by using techniques based on a Multisensor Fusion framework, which allows the integration of data coming from different sensors. In this paper, an approach to the synergic interpretation of data provided by thermal and visual sensors is proposed. Such integration is justified by the necessity for solving the ambiguities that may arise from separate data interpretations. The architecture of a distributed Knowledge-Based system is described. It performs an Intelligent Data Fusion process by integrating, in an opportunistic way, data acquired with a thermal and a video (b/w) camera. Data integration is performed at various architecture levels in order to increase the robustness of the whole recognition process. A priori models allow the system to obtain interesting data from both sensors; to transform such data into intermediate symbolic objects; and, finally, to recognize environmental situations on which to perform further processing. Some results are reported for different environmental conditions (i.e. a road scene by day and by night, with and without the presence of obstacles).

scholarly journals The Austrian Semantic EO Data Cube Infrastructure

2021 ◽  
Vol 13 (23) ◽  
pp. 4807
Author(s):  
Martin Sudmanns ◽  
Hannah Augustin ◽  
Lucas van der Meer ◽  
Andrea Baraldi ◽  
Dirk Tiede
Keyword(s):  
Land Cover ◽  
Knowledge Engineering ◽  
A Priori ◽  
Data Cube ◽  
Color Information ◽  
Data Cubes ◽  
Semantic Enrichment ◽  
Knowledge Based ◽  
Geographical Regions ◽  
Semantic Models

Big optical Earth observation (EO) data analytics usually start from numerical, sub-symbolic reflectance values that lack inherent semantic information (meaning) and require interpretation. However, interpretation is an ill-posed problem that is difficult for many users to solve. Our semantic EO data cube architecture aims to implement computer vision in EO data cubes as an explainable artificial intelligence approach. Automatic semantic enrichment provides semi-symbolic spectral categories for all observations as an initial interpretation of color information. Users graphically create knowledge-based semantic models in a convergence-of-evidence approach, where color information is modelled a-priori as one property of semantic concepts, such as land cover entities. This differs from other approaches that do not use a-priori knowledge and assume a direct 1:1 relationship between reflectance values and land cover. The semantic models are explainable, transferable, reusable, and users can share them in a knowledgebase. We provide insights into our web-based architecture, called Sen2Cube.at, including semantic enrichment, data models, knowledge engineering, semantic querying, and the graphical user interface. Our implemented prototype uses all Sentinel-2 MSI images covering Austria; however, the approach is transferable to other geographical regions and sensors. We demonstrate that explainable, knowledge-based big EO data analysis is possible via graphical semantic querying in EO data cubes.

A Priori knowledge based secure payload estimation

2017 ◽  
Vol 77 (14) ◽  
pp. 17889-17911 ◽  
Author(s):  
Sai Ma ◽  
Xianfeng Zhao ◽  
Qingxiao Guan ◽  
Zhoujun Xu ◽  
Yi Ma
Keyword(s):  
A Priori ◽  
A Priori Knowledge ◽  
Knowledge Based ◽  
Priori Knowledge

Secure and Reliable Knowledge-Based Intrusion Detection Using Mobile Base Stations in Smart Environments

2021 ◽  
pp. 500-513
Author(s):  
Ambika N.
Keyword(s):  
Intrusion Detection ◽  
Mobile Agent ◽  
Low Cost ◽  
Sensor Nodes ◽  
Base Stations ◽  
Wireless Sensor Nodes ◽  
Detection Scheme ◽  
Malicious Activity ◽  
Knowledge Based ◽  
Reliable Knowledge

Wireless sensor nodes are low cost tiny devices deployed in unsupervised environment. These devices require some kind of security mechanism to tackle different kinds of attacks. Intrusion detection is one such methodology used where the malicious activity is observed, and the target is isolated. Many authors have suggested different methodologies which are detailed in the work. The article also uses intrusion detection scheme to provide reliable network. A mobile agent and an assistance node aids in increasing security and efficiency of the work. The illegitimacy of the node is inferred using the data provided by the assistance and mobile agent. The work minimizes 12.9% of energy consumption, increases security by 3.025%, and increases reliability by 7.07% compared to the previous work.

P104 Prognostic value of Circulating Amino Acids (AAs) in Patients with Idiopathic Dilated Cardiomyopathy (DCM)

2020 ◽  
Vol 41 (Supplement_1) ◽  
Author(s):  
M Wakasa ◽  
Y Kawai ◽  
K Kajinami
Keyword(s):  
Amino Acids ◽  
Cardiac Function ◽  
Cardiac Death ◽  
Negative Association ◽  
Idiopathic Dilated Cardiomyopathy ◽  
Washout Rate ◽  
Lv Function ◽  
Reactive Oxygen Metabolites ◽  
Cardiac Events ◽  
Significant Positive Association

Abstract Backgrounds Circulating levels of some amino acids are significantly decreased in heart failure patients. However, relationship between their levels and cardiac function remains unclear. We therefore examined association between amino acid levels and cardiac function as prognostic predictor in DCM patients. Methods Consecutive 59 patients with DCM (M/F: 46/13, mean age: 59 years) were enrolled. We measured 25 kinds of plasma AA concentration, derivative of reactive oxygen metabolites (d-ROMs) as marker of oxidative stress, and washout rate of Tc-99m Sestamibi (WOR) as function of mitochondria and LVEF as LV function parameters. The occurrence of rehospitalization for cardiac events or cardiac death were followed during mean 1101 days (13-2626). Results Histidine, arginine and Fischer ratio (FR) showed a significant positive association with LVEF (p &lt; 0.05). Threonine and asparagine showed a significant negative association with WOR (P &lt; 0.05). Histidine and arginine showed a significant negative association with levels of d-ROMs (p &lt; 0.05).Rehospitalization for cardiac events and cardiac death were recorded in 16 patients (27%) and 6 patients (10%), respectively. Kaplan-Meier curves analysis showed similar trend of rehospitalization in subjects with lower FR and those with higher values. However, cardiac death in subjects with lower FR was observed more frequently as compared to those with higher values (22.2% vs 5.3% p &lt; 0.05). ConclusionsThe plasma FR could be a novel prognostic biomarker in DCM patients.

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