showing 43 related works from this author
Texture analysis of cardiac cine magnetic resonance imaging to detect nonviable segments in patients with chronic myocardial infarction.
2017
[EN] Purpose: To investigate the ability of texture analysis to differentiate between infarcted nonviable, viable, and remote segments on cardiac cine magnetic resonance imaging (MRI). Methods: This retrospective study included 50 patients suffering chronic myocardial infarction. The data were randomly split into training (30 patients) and testing (20 patients) sets. The left ventricular myocardium was segmented according to the 17-segment model in both cine and late gadolinium enhancement (LGE) MRI. Infarcted myocardium regions were identified on LGE in short-axis views. Nonviable segments were identified as those showing LGE 50%, and viable segments those showing 0 < LGE < 50% transmural …
Application of machine learning algorithms in thermal images for an automatic classification of lumbar sympathetic blocks
2023
Purpose There are no previous studies developing machine learning algorithms in the classification of lumbar sympathetic blocks (LSBs) performance using infrared thermography data. The objective was to assess the performance of different machine learning algorithms to classify LSBs carried out in patients diagnosed with lower limbs Complex Regional Pain Syndrome as successful or failed based on the evaluation of thermal predictors. Methods 66 LSBs previously performed and classified by the medical team were evaluated in 24 patients. 11 regions of interest on each plantar foot were selected within the thermal images acquired in the clinical setting. From every region of interest, different t…
Sequential cardiovascular magnetic resonance assessment of left ventricular ejection fraction for prediction of subsequent events in a large multicen…
2021
Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This work was supported by “Instituto de Salud Carlos III” and “Fondos Europeos de Desarrollo Regional FEDER” Background. Cardiovascular magnetic resonance (CMR) is the best tool for left ventricular ejection fraction (LVEF) quantification, but as yet the prognostic value of sequential LVEF assessment for major adverse cardiac event (MACE) prediction after ST-segment elevation myocardial infarction (STEMI) is uncertain. Purpose. We explored the prognostic impact of sequential assessment of CMR-derived LVEF after STEMI to predict subsequent MACE. Methods. We recruited 1036 STEMI p…
Magnetic Resonance Assessment of Left Ventricular Ejection Fraction at Any Time Post-Infarction for Prediction of Subsequent Events in a Large Multic…
2021
Background Magnetic resonance imaging (MRI) is the most accurate imaging technique for left ventricular ejection fraction (LVEF) quantification, but as yet the prognostic value of LVEF assessment at any time after ST-segment elevation myocardial infarction (STEMI) for subsequent major adverse cardiac event (MACE) prediction is uncertain. Purpose To explore the prognostic impact of MRI-derived LVEF at any time post-STEMI to predict subsequent MACE (cardiovascular death or re-admission for acute heart failure). Study Type Prospective. Population One thousand thirteen STEMI patients were included in a multicenter registry. Field Strength/Sequence 1.5-T. Balanced steady-state free precession (c…
Primary ciliary dyskinesia assessment by means of optical flow analysis of phase-contrast microscopy images
2014
Primary ciliary dyskinesia implies cilia with defective or total absence of motility, which may result in sinusitis, chronic bronchitis, bronchiectasis and male infertility. Diagnosis can be difficult and is based on an abnormal ciliary beat frequency (CBF) and beat pattern. In this paper, we present a method to determine CBF of isolated cells through the analysis of phase-contrast microscopy images, estimating cilia motion by means of an optical flow algorithm. After having analyzed 28 image sequences (14 with a normal beat pattern and 14 with a dyskinetic pattern), the normal group presented a CBF of 5.2 +/- 1.6 Hz, while the dyskinetic patients presented a 1.9 +/- 0.9 Hz CBF. The cutoff …
Schizophrenia with auditory hallucinations: A voxel-based morphometry study
2006
Many studies have shown widespread but subtle pathological changes in gray matter in patients with schizophrenia. Some of these studies have related specific alterations to the genesis of auditory hallucinations, particularly in the left superior temporal gyrus, but none has analysed the relationship between morphometric data and a specific scale for auditory hallucinations. The present study aims to define the presence and characteristics of structural abnormalities in relation with the intensity and phenomenology of auditory hallucinations by means of magnetic resonance voxel-based morphometry (MR-VBM) method applied on a highly homogeneous group of 18 persistent hallucinatory patients me…
Quantitative Analysis of Real-Time Infrared Thermography for the Assessment of Lumbar Sympathetic Blocks: A Preliminary Study
2021
Lumbar sympathetic blocks (LSBs) are commonly performed to treat pain ailments in the lower limbs. LSBs involve injecting local anesthetic around the nerves. The injection is guided by fluoroscopy which is sometimes considered to be insufficiently accurate. The main aim was to analyze the plantar foot skin temperature data acquired while performing LSBs in patients with complex regional pain syndrome (CRPS) affecting the lower limbs. Forty-four LSBs for treating lower limb CRPS in 13 patients were assessed. Pain medicine physicians visualized the infrared thermography (IRT) video in real time and classified the performance depending on the observed thermal changes within the first 4 min. Th…
Combined assessment of stress cardiovascular magnetic resonance and angiography to predict the effect of revascularization in chronic coronary syndro…
2021
Abstract Aims The role of revascularization in chronic coronary syndrome (CCS) and the value of ischaemia vs. anatomy to guide decision-making are in constant debate. We explored the potential of a combined assessment of ischaemic burden by vasodilator stress cardiovascular magnetic resonance (CMR) and presence of multivessel disease by angiography to predict the effect of revascularization on all-cause mortality in CCS. Methods and results The study group comprised 1066 CCS patients submitted to vasodilator stress CMR pre-cardiac catheterization (mean age 66 ± 11 years, 69% male). Stress CMR-derived ischaemic burden (extensive if &gt;5 ischaemic segments) and presence of multivessel di…
Ejection Fraction by Echocardiography for a Selective Use of Magnetic Resonance After Infarction
2020
[EN] Background Cardiac magnetic resonance (CMR) permits robust risk stratification of discharged ST-segment-elevation myocardial infarction patients, but its indiscriminate use in all cases is not feasible. We evaluated the utility of left ventricular ejection fraction (LVEF) by echocardiography for a selective use of CMR after ST-segment-elevation myocardial infarction. Methods Echocardiography and CMR were performed in 1119 patients discharged for ST-segment-elevation myocardial infarction included in a multicenter registry. The prognostic power of CMR beyond echocardiography-LVEF was assessed using adjusted C statistic, net reclassification improvement index, and integrated discriminati…
Automatic segmentation of the spine by means of a probabilistic atlas with a special focus on ribs suppression. Preliminary results
2015
Spine is a structure commonly involved in several prevalent diseases. In clinical diagnosis, therapy, and surgical intervention, the identification and segmentation of the vertebral bodies are crucial steps. However, automatic and detailed segmentation of vertebrae is a challenging task, especially due to the proximity of the vertebrae to the corresponding ribs and other structures such as blood vessels. In this study, to overcome these problems, a probabilistic atlas of the spine, including cervical, thoracic and lumbar vertebrae has been built to introduce anatomical knowledge in the segmentation process, aiming to deal with overlapping gray levels and the proximity to other structures. F…
Comparative Analysis of Tagging and Feature-Tracking Cardiac MRI Techniques for the Evaluation of Cardiac Deformation
2020
[EN] Currently, there is a high prevalence of cardiovascular diseases, being the leading cause of mortality worldwide. Thus, a rapid and effective evaluation of the heart is increasingly relevant to diagnose the patient early and achieve appropriate treatment. For this reason, this study aims to compare myocardial deformation parameters such as circumferential strain (segmental, base, mid, apical and global) and global torsion values by the CMR tissue tagging reference technique in SPAMM cine images and the promising feature-tracking technique in b-SSFP cine images, in 31 healthy subjects and 35 patients diagnosed with infarct. The results obtained showed that there is a high agreement in t…
Left orbitofrontal and superior temporal gyrus structural changes associated to suicidal behavior in patients with schizophrenia.
2008
Suicidal attempts are relatively frequent and clinically relevant in patients with schizophrenia. Recent studies have found gray matter differences in suicidal and non-suicidal depressive patients. However, no previous neuroimaging study has investigated possible structural abnormalities associated to suicidal behaviors in patients with schizophrenia. A whole-brain magnetic resonance voxel-based morphometric examination was performed on 37 male patients meeting the DSM-IV criteria for schizophrenia. Thirteen (35.14%) patients had attempted suicide. A non-parametric permutation test was computed to perform the comparability between groups. An analysis of covariance (AnCova) model was constru…
Magnetic Resonance MicroImaging of a Swine Infarcted Heart: Performing Cardiac Virtual Histologies
2015
The aim of this study is to develop a computer-aided intuitive software tool based on MATLAB to reproduce the functions of a virtual histology over Magnetic Resonance (MR) microimages of small samples of swine's infarcted hearts. The basic characterization consists of selecting regions of interest (ROIs) of that MR microimage and extracting the most important information of these regions. The software tool will implement intuitive and sophisticated tools that allow the user to define ROIs on the different types of images provided by the MR scanner. The final purpose of this tool will be to analyze the acquired data in order to characterize some aspects of the later possible events after a m…
A Ciliary Motility Index for Activity Measurement in Cell Cultures With Respiratory Syncytial Virus
2018
[EN] Background: The respiratory epithelium is frequently infected by the respiratory syncytial virus, resulting in inflammation, a reduction in cilia activity and an increase in the production of mucus. Methods: In this study, an automatic method has been proposed to characterize the ciliary motility from cell cultures by means of a motility index using a dense optical flow algorithm. This method allows us to determine the ciliary beat frequency (CBF) together with a ciliary motility index of the cells in the cultures. The object of this analysis is to automatically distinguish between normal and infected cells in a culture. Results: The method was applied in 2 stages. It was concluded fro…
Effect of ischemic postconditioning on microvascular obstruction in reperfused myocardial infarction. Results of a randomized study in patients and o…
2014
Background: Ischemic postconditioning (PCON) appears as a potentially beneficial tool in ST-segment elevation myocardial infarction (STEMI). We evaluated the effect of PCON on microvascular obstruction (MVO) in STEMI patients and in an experimental swine model. Methods: A prospective randomized study in patients and an experimental study in swine were carried out in two university hospitals in Spain. 101 consecutive STEMI patients were randomized to undergo primary angio-plasty followed by PCON or primary angioplasty alone (non-PCON). Using late gadolinium enhancement cardiovascular magnetic resonance, infarct size and MVO were quantified (% of left ventricular mass). In swine, using an ang…
Prognostic implications of dipyridamole cardiac MR imaging: a prospective multicenter registry
2011
Purpose: To evaluate dipyridamole cardiac magnetic resonance (MR) imaging in the prediction of major events (MEs) in patients with ischemic chest pain in a large multicenter registry. Materials and Methods: Institutional ethics committee approval and written informed consent were obtained. A total of 1722 patients who were undergoing cardiac MR imaging for chest pain were included. Wall motion abnormalities (WMAs) at rest, hyperemia perfusion defect (PD), late gadolinium enhancement (LGE), and inducible WMA were analyzed (abnormal if more than one abnormal segment was seen) with the 17-segment model. A cardiac MR categorization was created: category 1, no PD, LGE, or inducible WMA; category…
Additional diagnostic value of systolic dysfunction induced by dipyridamole stress cardiac magnetic resonance used in detecting coronary artery disea…
2009
Dipyridamole stress perfusion cardiovascular magnetic resonance (CMR) is used to detect coronary artery disease (CAD). However, few data are available on the diagnostic value of the systolic dysfunction induced by dipyridamole. This study investigated whether the induction of systolic dysfunction supplements the diagnostic information provided by perfusion imaging in the detection of CAD.Overall, 166 patients underwent dipyridamole CMR and quantitative coronary angiography, with CAD being defined as a stenosisor =70%. Systolic dysfunction at rest, systolic dysfunction with dipyridamole, induced systolic dysfunction, and stress first-pass perfussion deficit (PD) and delayed enhancement were …
Risk score for early risk prediction by cardiac magnetic resonance after acute myocardial infarction.
2022
BACKGROUND: Cardiac magnetic resonance (CMR) performed early after ST-segment elevation myocardial infarction (STEMI) can improve major adverse cardiac event (MACE) risk prediction. We aimed to create a simple clinical-CMR risk score for early MACE risk stratification in STEMI patients.; METHODS: We performed a multicenter prospective registry of reperfused STEMI patients (n=1118) in whom early (1-week) CMR-derived left ventricular ejection fraction (LVEF), infarct size and microvascular obstruction (MVO) were quantified. MACE was defined as a combined clinical endpoint of cardiovascular (CV) death, non-fatal myocardial infarction (NF-MI) or re-admission for acute decompensated heart failur…
Identifying the primary site of origin of MRI brain metastases from lung and breast cancer following a 2D radiomics approach
2017
Detection of brain metastases in patients with undiagnosed primary cancer is unusual but still an existing phenomenon. In these cases, identifying the cancer site of origin is non-feasible by visual examination of magnetic resonance (MR) images. Recently, radiomics has been proposed to analyze differences among classes of visually imperceptible imaging characteristics. In this study we analyzed 46 T1-weighted MR images of brain metastases from 29 patients: 29 of lung and 17 of breast origin. A total of 43 radiomics texture features were extracted from the metastatic lesions. Support vector machine (SVM) and k-nearest neighbors (k-NN) classifiers were implemented to evaluate the classificati…
PSPU-Net for Automatic Short Axis Cine MRI Segmentation of Left and Right Ventricles
2020
[EN] Characterization of the heart anatomy and function is mostly done with magnetic resonance image cine series. To achieve a correct characterization, the volume of the right and left ventricle need to be segmented, which is a timeconsuming task. We propose a new convolutional neural network architecture that combines U-net with PSP modules (PSPU-net) for the segmentation of left and right ventricle cavities and left ventricle myocardium in the diastolic frame of short-axis cine MRI images and compare its results against a classic 3D U-net architecture. We used a dataset containing 399 cases in total. The results showed higher quality results in both segmentation and final volume estimati…
Resultados de la estrategia farmacoinvasiva y de la angioplastia primaria en la reperfusión del infarto con elevación del segmento ST. Estudio con re…
2011
Introduction and objectives: Pharmacoinvasive strategy represents an attractive alternative to primary angioplasty. Using cardiovascular magnetic resonance imaging we compared the left ventricular outcome of the pharmacoinvasive strategy and primary angioplasty for the reperfusion of ST-segment elevation myocardial infarction. Methods: Cardiovascular magnetic resonance was performed 1 week and 6 months after infarction in two consecutive cohorts of patients included in a prospective university hospital ST-segment elevation myocardial infarction registry. During the period 2004-2006, 151 patients were treated with pharmacoinvasive strategy (thrombolysis followed by routine non-immediate angi…
Differentiation between acute and chronic myocardial infarction by means of texture analysis of late gadolinium enhancement and cine cardiac magnetic…
2017
[EN] The purpose of this study was to differentiate acute from chronic myocardial infarction using machine learning techniques and texture features extracted from cardiac magnetic resonance imaging (MRI). The study group comprised 22 cases with acute myocardial infarction (AMI) and 22 cases with chronic myocardial infarction (CMI). Cine and late gadolinium enhancement (LGE) MRI were analyzed independently to differentiate AMI from CMI. A total of 279 texture features were extracted from predefined regions of interest (ROIs): the infarcted area on LGE MRI, and the entire myocardium on cine MRI. Classification performance was evaluated by a nested cross-validation approach combining a feature…
Automatic left ventricle volume calculation with explainability through a deep learning weak-supervision methodology
2021
[EN] Background and objective: Magnetic resonance imaging is the most reliable imaging technique to assess the heart. More specifically there is great importance in the analysis of the left ventricle, as the main pathologies directly affect this region. In order to characterize the left ventricle, it is necessary to extract its volume. In this work we present a neural network architecture that is capable of directly estimating the left ventricle volume in short axis cine Magnetic Resonance Imaging in the end-diastolic frame and provide a segmentation of the region which is the basis of the volume calculation, thus offering explain-ability to the estimated value. Methods: The network was des…
Texture analysis for infarcted myocardium detection on delayed enhancement MRI
2017
Detection of infarcted myocardium in the left ventricle is achieved with delayed enhancement magnetic resonance imaging (DE-MRI). However, manual segmentation is tedious and prone to variability. We studied three texture analysis methods (run-length matrix, co-occurrence matrix, and autoregressive model) in combination with histogram features to characterize the infarcted myocardium. We evaluated 10 patients with chronic infarction to select the most discriminative features and to train a support vector machine (SVM) classifier. The classifier model was then used to segment five human hearts from the STACOM DE-MRI challenge at MICCAI 2012. The Dice coefficient was used to compare the segmen…
Emotional words induce enhanced brain activity in schizophrenic patients with auditory hallucinations.
2005
Neuroimaging studies of emotional response in schizophrenia have mainly used visual (faces) paradigms and shown globally reduced brain activity. None of these studies have used an auditory paradigm. Our principal aim is to evaluate the emotional response of patients with schizophrenia to neutral and emotional words. An auditory emotional paradigm based on the most frequent words heard by psychotic patients with auditory hallucinations was designed. This paradigm was applied to evaluate cerebral activation with functional magnetic resonance imaging (fMRI) in 11 patients with schizophrenia with persistent hallucinations and 10 healthy subjects. We found a clear enhanced activity of the fronta…
Microvascular perfusion 1 week and 6 months after myocardial infarction by first-pass perfusion cardiovascular magnetic resonance imaging
2006
To characterise the evolution of myocardial perfusion during the first 6 months after myocardial infarction by first-pass perfusion cardiovascular magnetic resonance imaging (CMR) and determine its significance.Prospective cohort design.Single-centre study in a teaching hospital in Spain.40 patients with a first ST-elevation myocardial infarction, single-vessel disease and thrombolysis in myocardial infarction (TIMI) grade 3 flow (stent in 33 patients) underwent rest and low-dose dobutamine CMR 7 (SD 1) and 184 (SD 11) days after infarction. Microvascular perfusion was assessed at rest by visual assessment and quantitative analysis of first-pass perfusion CMR. Of the 640 segments, 290 segme…
Vasodilator Stress CMR and All-Cause Mortality in Stable Ischemic Heart Disease
2020
Abstract Objectives This study explored the association of ischemic burden, as measured by vasodilator stress cardiovascular magnetic resonance (CMR), with all-cause mortality and the effect of revascularization on all-cause mortality in patients with stable ischemic heart disease (SIHD). Background In patients with SIHD, the association of ischemic burden, derived from vasodilator stress CMR, with all-cause mortality and its role for decision-making is unclear. Methods The registry consisted of 6,389 consecutive patients (mean age: 65 ± 12 years; 38% women) who underwent vasodilator stress CMR for known or suspected SIHD. The ischemic burden (at stress first-pass perfusion imaging) was com…
Analysis of the extension of Q-waves after infarction with body surface map: relationship with infarct size.
2006
We aimed to characterize the extension of Q-waves after a first ST-segment elevation myocardial infarction using body surface map (BSM) and its relationship with infarct size quantified with cardiovascular magnetic resonance imaging (CMR).Thirty-five patients were studied 6 months after a first ST-segment elevation myocardial infarction (23 anterior, 12 inferior). All cases had single-vessel disease and an open artery. The extension of Q-waves was analyzed by means of a 64-lead BSM. Infarct size was quantified with CMR. Absence of Q-waves in BSM was observed in 5 patients (14%), 2 of whom (40%) had1 segment with transmural necrosis. Absence of Q-waves in 12-lead ECG was observed in 8 patien…
Herramienta clínica para la búsqueda de biomarcadores de enfermedades neurológicas
2009
El solapamiento que presentan algunas enfermedades neurologicas en la clinica justifica la necesidad de establecer biomarcadores que sirvan como apoyo en el diagnostico y seguimiento de la enfermedad. El analisis de los fluidos intracraneales (sangre y liquido cefalorraquideo) juega un rol importante en la busqueda de estos biomarcadores. Las secuencias dinamicas de resonancia magnetica en contraste de fase (RM-CF) con sincronismo cardiaco permiten cuantificar el flujo de liquido cefalorraquideo (LCR) y de la sangre durante un ciclo cardiaco. No obstante, la medicion de flujo mediante secuencias de imagenes de RM-CF (IRM-CF) es precisa y reproducible siempre que se use un protocolo de adqui…
[Myocardial echocardiography with intracoronary injection of contrast in post-infarction patients. Implications and comparison with angiography and m…
2004
We analyzed the safety and feasibility of myocardial echocardiography with intracoronary injection of contrast, its effect on left ventricular remodeling and systolic function, and its relationship with angiography and magnetic resonance imaging (MRI) for the evaluation of post-infarction coronary microcirculation.Thirty patients with a first ST-elevation myocardial infarction and a patent infarct-related artery were studied. Mean perfusion score of the infarcted area was analyzed with myocardial echocardiography. TIMI and Blush grades (angiography) were determined. Mean perfusion score (MRI-perfusion), end-diastolic volume index and ejection fraction were determined with MRI. At 6 months a…
218 – Are there structural changes associated to suicidal behavior in patients with schizophrenia?
2008
Valor diagnóstico adicional de la disfunción sistólica inducida para la detección de enfermedad coronaria mediante resonancia magnética cardiaca de e…
2009
Introduccion y objetivos La perfusion con dipiridamol en resonancia magnetica cardiaca (RMC) de estres se utiliza para la deteccion de enfermedad de las arterias coronarias (EAC). Sin embargo, se carece de informacion sobre el valor diagnostico de la disfuncion sistolica (DS) inducida con dipiridamol. Este estudio se centra en investigar si la DS inducida aporta un valor diagnostico adicional junto con la perfusion para la deteccion de las EAC. Metodos Se sometio a 166 pacientes a una RMC con dipiridamol y a una angiografia coronaria cuantitativa. Se definio EAC para valores ≥ 70% de estenosis. Se analizo la extension de la DS en reposo, la DS con dipiridamol, la DS inducida, el deficit de …
Metabolomic Profile of Human Myocardial Ischemia by Nuclear Magnetic Resonance Spectroscopy of Peripheral Blood Serum
2012
Objectives The aim of this study was to investigate the metabolomic profile of acute myocardial ischemia (MIS) using nuclear magnetic resonance spectroscopy of peripheral blood serum of swine and patients undergoing angioplasty balloon‐induced transient coronary occlusion. Background Biochemical detection of MIS is a major challenge. The validation of novel biosignatures is of utmost importance. Methods High-resolution nuclear magnetic resonance spectroscopy was used to profile 32 blood serum metabolites obtained (before and after controlled ischemia) from swine (n 9) and patients (n 20) undergoing transitory MIS in the setting of planned coronary angioplasty. Additionally, blood serum of c…
Estudio de perfusión en pacientes postinfarto mediante ecografía miocárdica con inyección de contraste intracoronario. Implicaciones y relación con l…
2004
38 Objetivos. Analizamos la aplicabilidad y seguridad de la ecografia miocardica con inyeccion intracoronaria de contraste, su papel en la remodelacion ventricular y en la funcion sistolica, asi como su relacion con la angiografia y la resonancia magnetica para valorar la microcirculacion coronaria postinfarto. Pacientes y metodo. Se estudio a 30 pacientes con un primer infarto de miocardio con elevacion del segmento ST y arteria responsable abierta. Con inyeccion intracoronaria de contraste se determino la puntuacion media de perfusion en la zona infartada. Mediante angiografia se cuantificaron los grados TIMI y Blush. Se utilizo la resonancia magnetica para determinar la puntuacion media …
A radiomics evaluation of 2D and 3D MRI texture features to classify brain metastases from lung cancer and melanoma
2017
[EN] Brain metastases are occasionally detected before diagnosing their primary site of origin. In these cases, simple visual examination of medical images of the metastases is not enough to identify the primary cancer, so an extensive evaluation is needed. To avoid this procedure, a radiomics approach on magnetic resonance (MR) images of the metastatic lesions is proposed to classify two of the most frequent origins (lung cancer and melanoma). In this study, 50 T1-weighted MR images of brain metastases from 30 patients were analyzed: 27 of lung cancer and 23 of melanoma origin. A total of 43 statistical texture features were extracted from the segmented lesions in 2D and 3D. Five predictiv…
Comment on “Computer-Extracted Texture Features to Distinguish Cerebral Radionecrosis from Recurrent Brain Tumors on Multiparametric MRI: A Feasibili…
2017
We have read with great interest the article published by Tiwari et al, “Computer-Extracted Texture Features to Distinguish Cerebral Radionecrosis from Recurrent Brain Tumors on Multiparametric MRI: A Feasibility Study.”[1][1] In their article, they refer to our work regarding brain metastasis
Automatic segmentation of the spine by means of a probabilistic atlas with a special focus on ribs suppression
2017
[EN] Purpose: The development of automatic and reliable algorithms for the detection and segmentation of the vertebrae are of great importance prior to any diagnostic task. However, an important problem found to accurately segment the vertebrae is the presence of the ribs in the thoracic region. To overcome this problem, a probabilistic atlas of the spine has been developed dealing with the proximity of other structures, with a special focus on ribs suppression. Methods: The data sets used consist of Computed Tomography images corresponding to 21 patients suffering from spinal metastases. Two methods have been combined to obtain the final result: firstly, an initial segmentation is performe…
Routing Design in Wireless Sensor Networks and a Solution for Healthcare Environments
2011
This work presents the software implementation of a tissue engineering image analysis tool through the study of several biomaterials by means of different microscopy techniques (optical, scanning electron, and atomic force microscopy). With this tool, different quantitative information has been extracted from the microscopy image analysis of these biomaterials, as the number of objects, their mean size and the area they cover. Morphological characteristics, as the roundness or the porosity have been also obtained. All these quantitative information has permitted an statistical analysis over the obtained results.
Characterization of normal regional myocardial function by MRI cardiac tagging
2013
Purpose The aim of this study was to establish reference values for segmental myocardial strain measured by magnetic resonance (MR) cardiac tagging in order to characterize the regional function of the heart. Material and Methods We characterized the left ventricular (LV) systolic deformation in 39 subjects (26 women and 13 men, age 58.8 ± 11.6 years) whose cardiological study had not revealed any significant abnormality. The deformation was measured from MR-tagged (Siemens 1.5T MR) images using an algorithm based on sine wave modeling. Circumferential and radial peak systolic strain values along with the torsion angle and circumferential-longitudinal (CL) shear were determined in 16 LV seg…
Prognostic and therapeutic implications of dipyridamole stress cardiovascular magnetic resonance on the basis of the ischaemic cascade
2008
To determine the prognostic and therapeutic implications of stress perfusion cardiovascular magnetic resonance (CMR) on the basis of the ischaemic cascade.Single centre study in a teaching hospital in Spain.Dipyridamole stress CMR was performed on 601 patients with ischaemic chest pain and known or suspected coronary artery disease. On the basis of the ischaemic cascade, patients were categorised in C1 (no evidence of ischaemia, n = 354), C2 (isolated perfusion deficit at stress first-pass perfusion imaging, n = 181) and C3 (simultaneous perfusion deficit and inducible wall motion abnormalities, n = 66). CMR-related revascularisation (n = 102, 17%) was defined as the procedure prompted by t…
Automatic segmentation and 3D reconstruction of intravascular ultrasound images for a fast preliminar evaluation of vessel pathologies.
2007
Abstract Intravascular ultrasound (IVUS) imaging is used along with X-ray coronary angiography to detect vessel pathologies. Manual analysis of IVUS images is slow and time-consuming and it is not feasible for clinical purposes. A semi-automated method is proposed to generate 3D reconstructions from IVUS video sequences, so that a fast diagnose can be easily done, quantifying plaque length and severity as well as plaque volume of the vessels under study. The methodology described in this work has four steps: a pre-processing of IVUS images, a segmentation of media–adventitia contour, a detection of intima and plaque and a 3D reconstruction of the vessel. Preprocessing is intended to remove …
Support vector machine classification of brain metastasis and radiation necrosis based on texture analysis in MRI
2015
Purpose To develop a classification model using texture features and support vector machine in contrast-enhanced T1-weighted images to differentiate between brain metastasis and radiation necrosis. Methods Texture features were extracted from 115 lesions: 32 of them previously diagnosed as radiation necrosis, 23 as radiation-treated metastasis and 60 untreated metastases; including a total of 179 features derived from six texture analysis methods. A feature selection technique based on support vector machine was used to obtain a subset of features that provide optimal performance. Results The highest classification accuracy evaluated over test sets was achieved with a subset of ten features…
Resultados de la estrategia farmacoinvasiva y de la angioplastia primaria en la reperfusión del infarto con elevación del segmento ST. Estudio con re…
2011
[EN] Introduction and objectives: Pharmacoinvasive strategy represents an attractive alternative to primary angioplasty. Using cardiovascular magnetic resonance imaging we compared the left ventricular outcome of the pharmacoinvasive strategy and primary angioplasty for the reperfusion of ST-segment elevation myocardial infarction. Methods: Cardiovascular magnetic resonance was performed 1 week and 6 months after infarction in two consecutive cohorts of patients included in a prospective university hospital ST-segment elevation myocardial infarction registry. During the period 2004-2006, 151 patients were treated with pharmacoinvasive strategy (thrombolysis followed by routine non-immediate…