40 research outputs found
Automatic multiscale vascular image segmentation algorithm for coronary angiography
[Abstract] Cardiovascular diseases, particularly severe stenosis, are the main cause of death in the western world. The primary method of diagnosis, considered to be the standard in the detection and quantification of stenotic lesions, is a coronary angiography. This article proposes a new automatic multiscale segmentation algorithm for the study of coronary trees that offers results comparable to the best existing semi-automatic method. According to the state-of-the-art, a representative number of coronary angiography images that ensures the generalisation capacity of the algorithm has been used. All these images were selected by clinics from an Haemodynamics Unit. An exhaustive statistical analysis was performed in terms of sensitivity, specificity and Jaccard. Algorithm improvements imply that the clinician can perform tests on the patient and, bypassing the images through the system, can verify, in that moment, the intervention of existing differences in a coronary tree from a previous test, in such a way that it could change its clinical intra-intervention criteria.Galicia. Consellería de Cultura, Educación e Ordenación Universitaria; GRC2014/049Ministerio de Economía y Competitividad; TIN2015-70648-
Redesign and performance of an automatic segmentation method
[Resumen] La información más relevante de las angiografías coronarias se extrae empleando técnicas de segmentación, que pueden ser automáticas, semiautomáticas o manuales. Existen numerosos algoritmos de segmentación vascular, obteniendo mejores resultados, por normal general, aquellos que emplean múltiples técnicas e imágenes a diferentes escalas para proporcionar los resultados requeridos. Se presenta un nuevo método de segmentación automatizado basado en el método manual de Hamarneh incluyendo un estudio estadístico que demuestra su idoneidad para el problema
Measurement of the (eta c)(1S) production cross-section in proton-proton collisions via the decay (eta c)(1S) -> p(p)over-bar
The production of the state in proton-proton collisions is probed via its decay to the final state with the LHCb detector, in the rapidity range GeV/c. The cross-section for prompt production of mesons relative to the prompt cross-section is measured, for the first time, to be at a centre-of-mass energy TeV using data corresponding to an integrated luminosity of 0.7 fb, and at TeV using 2.0 fb. The uncertainties quoted are, in order, statistical, systematic, and that on the ratio of branching fractions of the and decays to the final state. In addition, the inclusive branching fraction of -hadron decays into mesons is measured, for the first time, to be , where the third uncertainty includes also the uncertainty on the inclusive branching fraction from -hadron decays. The difference between the and meson masses is determined to be MeV/c.The production of the state in proton-proton collisions is probed via its decay to the final state with the LHCb detector, in the rapidity range . The cross-section for prompt production of mesons relative to the prompt cross-section is measured, for the first time, to be at a centre-of-mass energy using data corresponding to an integrated luminosity of 0.7 fb , and at using 2.0 fb . The uncertainties quoted are, in order, statistical, systematic, and that on the ratio of branching fractions of the and decays to the final state. In addition, the inclusive branching fraction of -hadron decays into mesons is measured, for the first time, to be , where the third uncertainty includes also the uncertainty on the inclusive branching fraction from -hadron decays. The difference between the and meson masses is determined to be .The production of the state in proton-proton collisions is probed via its decay to the final state with the LHCb detector, in the rapidity range GeV/c. The cross-section for prompt production of mesons relative to the prompt cross-section is measured, for the first time, to be at a centre-of-mass energy TeV using data corresponding to an integrated luminosity of 0.7 fb, and at TeV using 2.0 fb. The uncertainties quoted are, in order, statistical, systematic, and that on the ratio of branching fractions of the and decays to the final state. In addition, the inclusive branching fraction of -hadron decays into mesons is measured, for the first time, to be , where the third uncertainty includes also the uncertainty on the inclusive branching fraction from -hadron decays. The difference between the and meson masses is determined to be MeV/c
Search for the lepton flavour violating decay tau(-) -> mu(-)mu(+)mu(-)
A search for the lepton flavour violating decay is performed with the LHCb experiment. The data sample corresponds to an integrated luminosity of 1.0 fb of proton-proton collisions at a centre-of-mass energy of 7 TeV and 2.0 fb at 8 TeV. No evidence is found for a signal, and a limit is set at 90% confidence level on the branching fraction, .A search for the lepton flavour violating decay τ → μ μ μ is performed with the LHCb experiment. The data sample corresponds to an integrated luminosity of 1.0 fb of proton-proton collisions at a centre-of-mass energy of 7 TeV and 2.0 fb at 8 TeV. No evidence is found for a signal, and a limit is set at 90% confidence level on the branching fraction, .A search for the lepton flavour violating decay is performed with the LHCb experiment. The data sample corresponds to an integrated luminosity of of proton-proton collisions at a centre-of-mass energy of and at . No evidence is found for a signal, and a limit is set at confidence level on the branching fraction,
Search for CP violation using T-odd correlations in D-0 -> K+K-pi(+)pi(-) decays
A search for violation using -odd correlations is performed using the four-body decay, selected from semileptonic decays. The data sample corresponds to integrated luminosities of and recorded at the centre-of-mass energies of 7 TeV and 8 TeV, respectively. The -violating asymmetry is measured to be . Searches for violation in different regions of phase space of the four-body decay, and as a function of the decay time, are also presented. No significant deviation from the conservation hypothesis is found
Measurement of CP asymmetry in B-s(0) -> D-s(-/+) K--/+ decays
We report on measurements of the time-dependent CP violating observables in decays using a dataset corresponding to 1.0 fb of pp collisions recorded with the LHCb detector. We find the CP violating observables , , , , , where the uncertainties are statistical and systematic, respectively. We use these observables to make the first measurement of the CKM angle in decays, finding = (115) modulo 180 at 68% CL, where the error contains both statistical and systematic uncertainties.We report on measurements of the time-dependent CP violating observables in B → D K decays using a dataset corresponding to 1.0 fb of pp collisions recorded with the LHCb detector. We find the CP violating observables C = 0.53±0.25±0.04, A = 0.37 ± 0.42 ± 0.20, , S = −1.09±0.33±0.08, , where the uncertainties are statistical and systematic, respectively. Using these observables together with a recent measurement of the B mixing phase −2β leads to the first extraction of the CKM angle γ from B → D K decays, finding γ = (115 )° modulo 180° at 68% CL, where the error contains both statistical and systematic uncertainties.We report on measurements of the time-dependent CP violating observables in decays using a dataset corresponding to 1.0 fb of pp collisions recorded with the LHCb detector. We find the CP violating observables , , , , , where the uncertainties are statistical and systematic, respectively. Using these observables together with a recent measurement of the mixing phase leads to the first extraction of the CKM angle from decays, finding = (115) modulo 180 at 68% CL, where the error contains both statistical and systematic uncertainties