Possible Patient Early Diagnosis by Ultrasonic Noninvasive Estimation of Thermal Gradients into Tissues Based on Spectral Changes Modeling

To achieve a precise noninvasive temperature estimation, inside patient tissues, would open promising research fields, because its clinic results would provide early-diagnosis tools. In fact, detecting changes of thermal origin in ultrasonic echo spectra could be useful as an early complementary indicator of infections, inflammations, or cancer. But the effective clinic applications to diagnosis of thermometry ultrasonic techniques, proposed previously, require additional research. Before their implementations with ultrasonic probes and real-time electronic and processing systems, rigorous analyses must be still made over transient echotraces acquired from well-controlled biological and computational phantoms, to improve resolutions and evaluate clinic limitations. It must be based on computing improved signal-processing algorithms emulating tissues responses. Some related parameters in echo-traces reflected by semiregular scattering tissues must be carefully quantified to get a precise processing protocols definition. In this paper, approaches for non-invasive spectral ultrasonic detection are analyzed. Extensions of author's innovations for ultrasonic thermometry are shown and applied to computationally modeled echotraces from scattered biological phantoms, attaining high resolution (better than 0.1°C). Computer methods are provided for viability evaluation of thermal estimation from echoes with distinct noise levels, difficult to be interpreted, and its effectiveness is evaluated as possible diagnosis tool in scattered tissues like liver

Estudio aerobiológico de la diversidad polínica y su potencial alergénico en el oasis del sur de Mendoza, Argentina

Los conocimientos provenientes del campo de estudio de la Aerobiología favorecen el análisis inmunológico de los alérgenos atmosféricos procedentes de polen y esporas fúngicas. Esto posibilita conocer la carga alergénica del aire en el ambiente y de esta manera, valorar mejor la relación exposición / reacción / clínica en los pacientes en tratamiento por alergias. No existen estudios previos de este tema realizados a nivel regional ni provincial en Mendoza. Una base de datos de identificación de posibles alérgenos provenientes de la polinización de espacios verdes urbanos en la ciudad de San Rafael y General Alvear contribuye a la epidemiología ambiental sobre las afecciones alérgicas respiratorias inducidas por polen y esporas. En esta presentación damos a conocer un proyecto de investigación en Aerobiología, con el fin de generar conocimiento aerobiológico de la zona urbana del oasis del sur mendocino (San Rafael y General Alvear), que contribuye a conocer la carga alergénica proveniente de granos de polen y esporas presentes en el ambiente. Para ello, se están llevando a cabo tres líneas de trabajo que consisten en: (1) el relevamiento, localización y mapeo de la vegetación urbana en floración, (2) la elaboración de una colección de referencia palinológica, y (3) el muestreo diario de aeropartículas atmosféricas urbanas. Se presentan los resultados preliminares obtenidos desde el inicio del proyecto y se muestran las líneas de trabajo que seguirá el curso de esta investigación. A futuro, los estudios aerobiológicos permitirían el desarrollo de programas de seguimiento, prevención y control en los índices de la cantidad de polen y esporas presentes en la atmósfera. Esta herramienta puede describir el potencial alergénico en espacios urbanos sus perjuicios ambientales. De esta manera, una investigación con estas características puede ser un aporte directo a la formulación de políticas de salud pública y planificación urbana de la ciudad.Fil: Guerci, Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; Argentina. Museo Municipal de Historia Natural San Rafael - Unidad Asociada al CCT Mendoza; Argentina. Instituto de Enseñanza Superior 9-011 del Atuel; ArgentinaFil: Rojo, Leandro David. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; Argentina. Museo Municipal de Historia Natural San Rafael - Unidad Asociada al CCT Mendoza; ArgentinaFil: Indiveri, Martina. Gobierno de la Provincia de Mendoza. Hospital Teodoro Schestakow.; ArgentinaFil: Nuñez Sada, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Farina, Lucia. Museo Municipal de Historia Natural San Rafael - Unidad Asociada al CCT Mendoza; ArgentinaFil: Aguilar, Mariano. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; Argentina. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Llano, Carina Lourdes. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Mendoza; ArgentinaFil: Lucero, A.. Universidad de Mendoza; ArgentinaFil: Negreira, Gabriel Alfredo. Instituto de Enseñanza Superior 9-011 del Atuel; ArgentinaFil: Vazquez, Maria Soledad. Universidad Tecnologica Nacional. Facultad Reg.san Rafael. Instituto de Evolucion, Ecologia Historica y Ambiente. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mendoza. Instituto de Evolucion, Ecologia Historica y Ambiente.; ArgentinaFil: Rodriguez, L. F.. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Gallardo, C. A.. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Giraudo, S. B.. Museo Municipal de Historia Natural San Rafael - Unidad Asociada al CCT Mendoza; ArgentinaXIV Encuentro del Centro Internacional de Ciencias de la TierraSan RafaelArgentinaCentro Internacional para Estudios de la TierraComisión Nacional de Energía AtómicaUniversidad Nacional de CuyoUniversidad Tecnológica Nacional. Facultad Regional San Rafae

Asymptomatic internal carotid artery stenosis and cerebrovascular risk stratification

Background The purpose of this study was to determine the cerebrovascular risk stratification potential of baseline degree of stenosis, clinical features, and ultrasonic plaque characteristics in patients with asymptomatic internal carotid artery (ICA) stenosis. Methods This was a prospective, multicenter, cohort study of patients undergoing medical intervention for vascular disease. Hazard ratios for ICA stenosis, clinical features, and plaque texture features associated with ipsilateral cerebrovascular or retinal ischemic (CORI) events were calculated using proportional hazards models. Results A total of 1121 patients with 50% to 99% asymptomatic ICA stenosis in relation to the bulb (European Carotid Surgery Trial [ECST] method) were followed-up for 6 to 96 months (mean, 48). A total of 130 ipsilateral CORI events occurred. Severity of stenosis, age, systolic blood pressure, increased serum creatinine, smoking history of more than 10 pack-years, history of contralateral transient ischemic attacks (TIAs) or stroke, low grayscale median (GSM), increased plaque area, plaque types 1, 2, and 3, and the presence of discrete white areas (DWAs) without acoustic shadowing were associated with increased risk. Receiver operating characteristic (ROC) curves were constructed for predicted risk versus observed CORI events as a measure of model validity. The areas under the ROC curves for a model of stenosis alone, a model of stenosis combined with clinical features and a model of stenosis combined with clinical, and plaque features were 0.59 (95% confidence interval [CI] 0.54-0.64), 0.66 (0.62-0.72), and 0.82 (0.78-0.86), respectively. In the last model, stenosis, history of contralateral TIAs or stroke, GSM, plaque area, and DWAs were independent predictors of ipsilateral CORI events. Combinations of these could stratify patients into different levels of risk for ipsilateral CORI and stroke, with predicted risk close to observed risk. Of the 923 patients with <70% stenosis, the predicted cumulative 5-year stroke rate was <5% in 495, 5% to 9.9% in 202, 10% to 19.9% in 142, and <20% in 84 patients. Conclusion Cerebrovascular risk stratification is possible using a combination of clinical and ultrasonic plaque features. These findings need to be validated in additional prospective studies of patients receiving optimal medical intervention alone. Copyright © 2010 by the Society for Vascular Surgery

The size of juxtaluminal hypoechoic area in ultrasound images of asymptomatic carotid plaques predicts the occurrence of stroke

Objective: To test the hypothesis that the size of a juxtaluminal black (hypoechoic) area (JBA) in ultrasound images of asymptomatic carotid artery plaques predicts future ipsilateral ischemic stroke. Methods: A JBA was defined as an area of pixels with a grayscale value &lt;25 adjacent to the lumen without a visible echogenic cap after image normalization. The size of a JBA was measured in the carotid plaque images of 1121 patients with asymptomatic carotid stenosis 50% to 99% in relation to the bulb (Asymptomatic Carotid Stenosis and Risk of Stroke study); the patients were followed for up to 8 years. Results: The JBA had a linear association with future stroke rate. The area under the receiver-operating characteristic curve was 0.816. Using Kaplan-Meier curves, the mean annual stroke rate was 0.4% in 706 patients with a JBA &lt;4 mm 2, 1.4% in 171 patients with a JBA 4 to 8 mm2, 3.2% in 46 patients with a JBA 8 to 10 mm2, and 5% in 198 patients with a JBA &gt;10 mm2 (P &lt;.001). In a Cox model with ipsilateral ischemic events (amaurosis fugax, transient ischemic attack [TIA], or stroke) as the dependent variable, the JBA (&lt;4 mm2, 4-8 mm2, &gt;8 mm2) was still significant after adjusting for other plaque features known to be associated with increased risk, including stenosis, grayscale median, presence of discrete white areas without acoustic shadowing indicating neovascularization, plaque area, and history of contralateral TIA or stroke. Plaque area and grayscale median were not significant. Using the significant variables (stenosis, discrete white areas without acoustic shadowing, JBA, and history of contralateral TIA or stroke), this model predicted the annual risk of stroke for each patient (range, 0.1%-10.0%). The average annual stroke risk was &lt;1% in 734 patients, 1% to 1.9% in 94 patients, 2% to 3.9% in 134 patients, 4% to 5.9% in 125 patients, and 6% to 10% in 34 patients. Conclusions: The size of a JBA is linearly related to the risk of stroke and can be used in risk stratification models. These findings need to be confirmed in future prospective studies or in the medical arm of randomized controlled studies in the presence of optimal medical therapy. In the meantime, the JBA may be used to select asymptomatic patients at high stroke risk for carotid endarterectomy and spare patients at low risk from an unnecessary operation

Natural History of MYH7-Related Dilated Cardiomyopathy

BACKGROUND: Variants in myosin heavy chain 7 (MYH7) are responsible for disease in 1% to 5% of patients with dilated cardiomyopathy (DCM); however, the clinical characteristics and natural history of MYH7-related DCM are poorly described. OBJECTIVE: We sought to determine the phenotype and prognosis of MYH7-related DCM. We also evaluated the influence of variant location on phenotypic expression. METHODS: We studied clinical data from 147 individuals with DCM-causing MYH7 variants (47.6% female; 35.6 ± 19.2 years) recruited from 29 international centers. RESULTS: At initial evaluation, 106 (72.1%) patients had DCM (left ventricular ejection fraction: 34.5% ± 11.7%). Median follow-up was 4.5 years (IQR: 1.7-8.0 years), and 23.7% of carriers who were initially phenotype-negative developed DCM. Phenotypic expression by 40 and 60 years was 46% and 88%, respectively, with 18 patients (16%) first diagnosed at <18 years of age. Thirty-six percent of patients with DCM met imaging criteria for LV noncompaction. During follow-up, 28% showed left ventricular reverse remodeling. Incidence of adverse cardiac events among patients with DCM at 5 years was 11.6%, with 5 (4.6%) deaths caused by end-stage heart failure (ESHF) and 5 patients (4.6%) requiring heart transplantation. The major ventricular arrhythmia rate was low (1.0% and 2.1% at 5 years in patients with DCM and in those with LVEF of ≤35%, respectively). ESHF and major ventricular arrhythmia were significantly lower compared with LMNA-related DCM and similar to DCM caused by TTN truncating variants. CONCLUSIONS: MYH7-related DCM is characterized by early age of onset, high phenotypic expression, low left ventricular reverse remodeling, and frequent progression to ESHF. Heart failure complications predominate over ventricular arrhythmias, which are rare

Investigating the role of ultrasonic scattering in the wave absorption phenomenon

Ponencia presentada en el XIX Congreso Internacional de Acústica (ICA2007), Madrid, 2-7 Sep 2007.-- PACS: Cs 43.35.Ud.To calculate the thermal dose in therapeutic ultrasound only the absorption phenomenon is considered. Nevertheless scattering can be non negligible, thus influencing global attenuation and consequently the thermal dose. This work proposes an experimental approach of the role scattering has in temperature generated by therapeutic ultrasound in biological phantoms. These phantoms mimic the acoustical and thermal properties of biological tissues. This study was conducted with continuous wave ultrasound at 1 and 3 MHz and 2 W/cm2. Five phantoms were used in the experiments. The first one composed of one single agar-gel based layer 85-mm thick. The others composed of two layers: one of 42-mm agar-gel and the other with 43-mm agar-gel mixed with graphite or PVC powder as scatterers. Seven thin thermocouples were inserted in the phantoms (two in the first layer and the others in the second one, 5 mm from each other) and connected to standard instrumentation. The phantoms were heated by ultrasound for 10 min. Preliminary results show that the layer with graphite powder reaches up to 4ºC more than the other phantoms at the same depth. Therefore, we have an initial indication how scattering can influence heating patterns and should be taken in consideration, at least in some scenarios.For elaboration of this work the support of the CYTED/CNPq (PULSETS) project and ALPHA N I-0343-FA-FCD-FI (PETRA II) program has been received.Peer reviewe

Linear versus non-linear non-invasive temperature predictors in a homogeneous medium subjected to physiotherapeutic ultrasound

The lack of accurate time-spatial temperature estimators/predictors conditions the safe application of thermal therapies, such as hyperthermia. In this paper, a comparison between a linear and a non-linear class of models for non-invasive temperature prediction in a homogeneous medium, subjected to ultrasound at physiotherapeutic levels is presented. The linear models used were autoregressive with exogenous inputs (ARX) and the non-linear models were radial basis functions neural networks (RBFNN). In order to create and validate the models, an experiment was build to extract in vitro ultrasound RF-lines, as well as its correspondent temperature values. Then, features were extracted from the measured RF-lines and the models were trained and validated. For both the models, the best-fitted structures were selected using the multi-objective genetic algorithm (MOGA), given the enormous number of possible structures. The best RBFNN model presented a maximum absolute predictive error in the validation set five times less than the value presented by the best ARX model. In this work, the best RBFNN reached a maximum absolute error of 0.42 ºC, which is bellow the value pointed as a borderline between an appropriate and an undesired temperature estimator, which is 0.5 ºC. The average error was one order of magnitude less in the RBFNN case, and a less biased estimation was met. In addition, the best RBFNN needed less environmental information (inputs), given the capacity to non-linearly relate the information. The results obtained are encouraging, considering that coherent results should be obtained in a time-spatial modelling schema using RBFNN models

Single black-box models for two-point non-invasive temperature prediction

In this paper the performance of a genetically selected radial basis functions neural network is evaluated for non-invasive two-point temperature estimation in a homogeneous medium, irradiated by therapeutic ultrasound at physiotherapeutic levels. In this work a single neural network was assigned to estimate the temperature profile at the two considered points, and more consistent results were obtained than when considering one model for each point. This result was possible by increasing the model complexity. The best model predicts the temperature from two unseen data sequences during approximately 2 hours, with a maximum absolute error less than 0.5 oC, as desired for a therapeutic temperature estimator