Search results for "ALGORITHMS"
showing 10 items of 1716 documents
Workflow-centred open-source fully automated lung volumetry in chest CT
2019
Aim To develop a robust open-source method for fully automated extraction of total lung capacity (TLC) from computed tomography (CT) images and to demonstrate its integration into the clinical workflow. Materials and methods Using only open-source software, an algorithm was developed based on a region-growing method that does not require manual interaction. Lung volumes calculated from reconstructions with different kernels (TLCCT) were assessed. To validate the algorithm calculations, the results were correlated to TLC measured by pulmonary function testing (TLCPFT) in a subgroup of patients for which this information was available within 3 days of the CT examination. Results A total of 28…
The cumulative amount of serum-free light chain is a strong prognosticator in chronic lymphocytic leukemia.
2011
AbstractIdentification of patients at risk of early disease progression is the mainstay of tailored management in chronic lymphocytic leukemia (CLL). Although application of established biomarkers is limited by intrinsic detection/readout complexities, abnormality of κ and λ serum-free light chain ratio [sFLC (κ/λ)] was proposed as a straightforward prognosticator in CLL. By analyzing 449 therapy-naive patients, we show that an abnormal sFLC(κ/λ), along with CD38, ZAP-70, IGHV mutations, cytogenetics and stage, independently predicts treatment-free survival (TFS) but becomes prognostically irrelevant if the cumulative amount of clonal and nonclonal FLCs [sFLC(κ + λ)], a variable associated …
Information Theoretic Entropy for Molecular Classification: Oxadiazolamines as Potential Therapeutic Agents
2013
In this review we present algorithms for classification and taxonomy based on information entropy, followed by structure-activity relationship (SAR) models for the inhibition of human prostate carcinoma cell line DU-145 by 26 derivatives of N-aryl-N-(3-aryl-1,2,4-oxadiazol-5-yl)amines (NNAs). The NNAs are classified using two characteristic chemical properties based on different regions of the molecules. A table of periodic properties of inhibitors of DU-145 human prostate carcinoma cell line is obtained based on structural features from the amine moiety and from the oxadiazole ring. Inhibitors in the same group and period of the periodic table are predicted to have highly similar propertie…
A supervised learning framework of statistical shape and probability priors for automatic prostate segmentation in ultrasound images
2013
Prostate segmentation aids in prostate volume estimation, multi-modal image registration, and to create patient specific anatomical models for surgical planning and image guided biopsies. However, manual segmentation is time consuming and suffers from inter-and intra-observer variabilities. Low contrast images of trans rectal ultrasound and presence of imaging artifacts like speckle, micro-calcifications, and shadow regions hinder computer aided automatic or semi-automatic prostate segmentation. In this paper, we propose a prostate segmentation approach based on building multiple mean parametric models derived from principal component analysis of shape and posterior probabilities in a multi…
A simple analytical method for heterogeneity corrections in low dose rate prostate brachytherapy
2015
In low energy brachytherapy, the presence of tissue heterogeneities contributes significantly to the discrepancies observed between treatment plan and delivered dose. In this work, we present a simplified analytical dose calculation algorithm for heterogeneous tissue. We compare it with Monte Carlo computations and assess its suitability for integration in clinical treatment planning systems. The algorithm, named as RayStretch, is based on the classic equivalent path length method and TG-43 reference data. Analytical and Monte Carlo dose calculations using Penelope2008 are compared for a benchmark case: a prostate patient with calcifications. The results show a remarkable agreement between …
Reproducibility of CT Radiomic Features within the Same Patient: Influence of Radiation Dose and CT Reconstruction Settings.
2019
Background Results of recent phantom studies show that variation in CT acquisition parameters and reconstruction techniques may make radiomic features largely nonreproduceable and of limited use for prognostic clinical studies. Purpose To investigate the effect of CT radiation dose and reconstruction settings on the reproducibility of radiomic features, as well as to identify correction factors for mitigating these sources of variability. Materials and Methods This was a secondary analysis of a prospective study of metastatic liver lesions in patients who underwent staging with single-energy dual-source contrast material-enhanced staging CT between September 2011 and April 2012. Technique p…
Quantification of epicardial adipose tissue in coronary calcium score and CT coronary angiography image data sets: comparison of attenuation values, …
2016
The aim of the study was to compare epicardial adipose tissue (EAT) characteristics assessed with coronary calcium score (CS) and CT coronary angiography (CTCA) image data sets.In 76 patients (mean age 59 ± 13 years) who underwent CS and CTCA owing to suspected coronary artery disease (CAD), EAT was quantified in terms of density (Hounsfield units), thickness and volume. The EAT volume was extracted with a semi-automatic software.A moderate correlation was found between EAT density in CS and CTCA image data sets (-100 ± 19 HU vs -70 ± 24 HU; p 0.05, r = 0.55). The distribution of EAT was not symmetrical with a maximal thickness at the right atrioventricular groove (14.2 ± 5.3 mm in CS, 15.…
Computed tomography coronary angiography vs. stress ECG in patients with stable angina
2009
PURPOSE: This study compared the role of multislice computed tomography coronary angiography (MSCT-CA) and stress electrocardiography (ECG) in the diagnostic workup of patients with chronic chest pain. MATERIALS AND METHODS: MSCT-CA was performed in 43 patients (31 men, 12 women, mean age 58.8+/-7.7 years) with stable angina after a routine diagnostic workup involving stress ECG and conventional CA. The following inclusion criteria were adopted: sinus rhythm and ability to hold breath for 12 s. Beta-blockers were administered in patients with heart rate>or=70 beats/minute. In order to identify or exclude patients with significant stenoses (>or=50% lumen), we determined posttest likelihood r…
Prediction of the mesiodistal size of unerupted canines and premolars for a group of Romanian children: a comparative study
2013
Objectives The aim of the present study was to develop an optimization method of multiple linear regression equation (MLRE), using a genetic algorithm to determine a set of coefficients that minimize the prediction error for the sum of permanent premolars and canine dimensions in a group of young people from a central area of Romania represented by a city called Sibiu. Material and Methods To test the proposed method, we used a multiple linear regression equation derived from the estimation method proposed by Mojers, to which we adjusted regression coefficients using the Breeder genetic algorithm. A total of 92 children were selected with complete permanent teeth with no clinically visible …
Cross-frequency coupling between gamma oscillations and deep brain stimulation frequency in Parkinson's disease.
2020
Abstract The disruption of pathologically enhanced beta oscillations is considered one of the key mechanisms mediating the clinical effects of deep brain stimulation on motor symptoms in Parkinson’s disease. However, a specific modulation of other distinct physiological or pathological oscillatory activities could also play an important role in symptom control and motor function recovery during deep brain stimulation. Finely tuned gamma oscillations have been suggested to be prokinetic in nature, facilitating the preferential processing of physiological neural activity. In this study, we postulate that clinically effective high-frequency stimulation of the subthalamic nucleus imposes cross-…