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1.
Brain Sci ; 9(10)2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31627490

RESUMO

We report the case of a male multiple sclerosis (MS) patient with type 2 diabetes (T2D), asthma, major depression (MD or major depressive disorder, MDD), and other chronic conditions, after his recent difficulties with craniopharyngioma and cranial nerve-VI (CN6) palsy. In addition, we show magnetic resonance image and spectroscopy (MRI, MRS), Humphrey's Visual Field (HVF), and retinal nerve fiber layer thickness (RNFLT) findings to explain the changes in the patient's health, and discuss the methods that helped/help him sustain productivity and euthymia despite long-standing problems and new CNS changes.

2.
J Tehran Heart Cent ; 11(3): 105-110, 2016 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-27956909

RESUMO

Background: The late postoperative course for children with transposition of the great arteries (TGA) with an intact ventricular septum (IVS) is very important because the coronary arteries may be at risk of damage during arterial switch operation (ASO). We sought to investigate left ventricular function in patients with TGA/IVS by echocardiography. Methods: From March 2011 to December 2012, totally 20 infants (12 males and 8 females) with TGA/IVS were evaluated via 2-dimensional speckle-tracking echocardiography (2D STE) more than 6 months after they underwent ASO. A control group of age-matched infants and children was also studied. Left ventricular longitudinal strain (S), strain rate (SR), time to peak systolic longitudinal strain (TPS), and time to peak systolic longitudinal strain rate (TPSR) were measured and compared between the 2 groups. Results: Mean ± SD of age at the time of study in the patients with TGA/IVS was 15 ± 5 months, and also age at the time of ASO was 12 ± 3 days. Weight was 3.13 ± 0.07 kg at birth and 8.83 ± 1.57 kg at the time of ASO. Global strain (S), Time to peak strain rate (TPSR), and Time to peak strain (TPS) were not significantly different between the 2 groups, whereas global strain rate (SR) was significantly different (p value < 0.001). In the 3-chamber view, the values of S in the lateral, septal, inferior, and anteroseptal walls were significantly different between the 2 groups (p value < 0.001), and SR in the posterior wall was significantly different between the 2 groups (p value < 0.001). There were no positive correlations between S and SR in terms of the variables of heart rate, total cardiopulmonary bypass time, and aortic cross-clamp time. There were no statistically significant differences between the 2 groups regarding S, SR, TPS, and TPSR in the anteroseptal and posterior walls in the 3-chamber view and in the lateral and septal walls in the 4-chamber view. Conclusion: We showed that between 6 and 18 months after a successful ASO, the parameters of S, SR, and global TPS were normal in our patients with TGA/IVS. However, LV myocardial TPSR did not normalize in this time period.

3.
J Med Syst ; 40(1): 16, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26573653

RESUMO

This paper presents a robust device for automated screening of pediatric heart diseases based on our unique processing method in murmur characterization; the Arash-Band method. The present study modifies the Arash-Band method and employs output of the modified method in conjunction with the two other original techniques to extract indicative feature vectors for the screening. The extracted feature vectors are classified by using the support vector machine method. Results show that the proposed modifications significantly enhances performance of the Arash-Band in terms of the both accuracy and sensitivity as the corresponding effect sizes are sufficiently large. The proposed algorithm has been incorporated into an Android-based tablet to constitute an intelligent phonocardiogram with the automatic screening capability. In order to obtain confidence interval of the accuracy and sensitivity, an inferable statistical test is applied on our database containing the phonocardiogram signals recorded from 263 of the referrals to a hospital. The expected value of the accuracy/sensitivity is estimated to be 87.45 % / 87.29 % with a 95 % confidence interval of (80.19 % - 92.47 %) / (76.01 % - 95.78 %) exhibiting superior performance than a pediatric cardiologist who relies on conventional or even computer-assisted auscultation.


Assuntos
Algoritmos , Eletrocardiografia/instrumentação , Cardiopatias/diagnóstico , Fonocardiografia/instrumentação , Processamento de Sinais Assistido por Computador/instrumentação , Adolescente , Criança , Pré-Escolar , Computadores de Mão , Humanos , Lactente , Imagem Multimodal , Reprodutibilidade dos Testes
4.
Cardiovasc Eng Technol ; 6(4): 546-56, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26577485

RESUMO

This paper presents a novel processing method for heart sound signal: the statistical time growing neural network (STGNN). The STGNN performs a robust classification by merging supervised and unsupervised statistical methods to overcome non-stationary behavior of the signal. By combining available preprocessing and segmentation techniques and the STGNN classifier, we build an automatic tool for screening children with isolated BAV, the congenital heart malformation which can lead to serious cardiovascular lesions. Children with BAV (22 individuals) and healthy condition (28 individuals) are subjected to the study. The performance of the STGNN is compared to that of a time growing neural network (CTGNN) and a conventional support vector (CSVM) machine, using balanced repeated random sub sampling. The average of the accuracy/sensitivity is estimated to be 87.4/86.5 for the STGNN, 81.8/83.4 for the CTGNN, and 72.9/66.8 for the CSVM. Results show that the STGNN offers better performance and provides more immunity to the background noise as compared to the CTGNN and CSVM. The method is implementable in a computer system to be employed in primary healthcare centers to improve the screening accuracy.


Assuntos
Valva Aórtica/anormalidades , Doenças das Valvas Cardíacas/congênito , Doenças das Valvas Cardíacas/diagnóstico , Algoritmos , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/fisiopatologia , Doença da Válvula Aórtica Bicúspide , Criança , Pré-Escolar , Ecocardiografia/métodos , Feminino , Ruídos Cardíacos/fisiologia , Doenças das Valvas Cardíacas/diagnóstico por imagem , Doenças das Valvas Cardíacas/fisiopatologia , Humanos , Masculino , Redes Neurais de Computação , Fonocardiografia , Sensibilidade e Especificidade , Processamento de Sinais Assistido por Computador , Máquina de Vetores de Suporte
5.
Pediatr Cardiol ; 34(1): 129-34, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22864675

RESUMO

The fundamental role of pulmonary vascular resistance in the Fontan circulation is obvious. Medications decreasing this resistance may have an impact on the fate of this population. Hence, we assessed noninvasively the effect of oral sildenafil on the ventriculo-arterial coupling in patients with Fontan circulation. In a single-center, prospective case series study, 23 patients with fenestrated extracardiac total cavopulmonary connection age 12-31 years were enrolled in this study. Clinical characteristics and echocardiographic examination were performed before and after a 1 week course of sildenafil at 0.5 mg/kg every 8 h. Sildenafil had no effect on heart rate and blood pressure. However, oxygen saturation was significantly increased with sildenafil (87.6 ± 4.3 vs. 90.1 ± 3.6; P < 0.0001). The calculated noninvasive ventricular end-systolic elastance (Ees) was greater after sildenafil compared with the pre-sildenafil values (1.59 ± 0.17 vs. 1.72 ± 0.27 mm Hg/ml; P = 0.001). Moreover, significant decreases in arterial elastance (Ea) (1.62 ± 0.53 vs. 1.36 ± 0.43 mm Hg/ml; P < 0.0001), ventricular end-diastolic elastance (Eed) (0.05 ± 0.021 vs. 0.04 ± 0.013; P = 0.002), and, finally, ventriculo-arterial coupling index (0.99 ± 0.26 vs. 0.76 ± 0.15; P < 0.0001) were found after sildenafil administration. The intolerable side effects that led to stopping the sildenafil occurred only in one (4 %) patient. Sildenafil has increased ventricular systolic elastance and improved ventriculo-arterial coupling in patients palliated with Fontan circulation. Short-term sildenafil was well tolerated in most of the patients with only minor side effects.


Assuntos
Ecocardiografia/métodos , Derivação Cardíaca Direita/métodos , Piperazinas/administração & dosagem , Sulfonas/administração & dosagem , Resistência Vascular/efeitos dos fármacos , Vasodilatadores/administração & dosagem , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Piperazinas/efeitos adversos , Estudos Prospectivos , Purinas/administração & dosagem , Purinas/efeitos adversos , Citrato de Sildenafila , Sulfonas/efeitos adversos , Vasodilatadores/efeitos adversos , Adulto Jovem
6.
Iran J Pediatr ; 23(4): 445-50, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24427499

RESUMO

OBJECTIVE: Intelligent electronic stethoscopes and computer-aided auscultation systems have highlighted a new era in cardiac auscultation in children. Several collaborative multidisciplinary researches in this field are performed by physicians and computer specialists. Recently, a novel medical software device, Automated Auscultation Diagnosis Device (AADD), has been reported with intelligent diagnosing ability to differentiate cardiac murmur from breath sounds in children with normal and abnormal hearts due to congenital heart disease. The aim of this study is to determine efficiency, sensitivity and specificity of the diagnoses made by this AADD in children with and without cardiac disease. METHODS: We performed a cross-sectional study to determine efficiency, sensitivity and specificity of diagnoses made by AADD. Our patient population was two groups of children with and without cardiac disease(563 patients and 50 normal). SPSS version 16 was used to calculate sensitivity, specificity and efficiency and descriptive analysis. FINDINGS: Using cardiac sound recording in four conventional cardiac areas of auscultation (including aortic, pulmonary, tricuspid and mitral), AADD proved to have a ≥90% sensitivity, specificity and efficiency for making the correct diagnosis in children with heart disease and 100% diagnostic accuracy in children with normal hearts either with or without innocent murmurs. CONCLUSION: Considering the high sensitivity, specificity and efficiency of AADD for making the correct diagnosis, application of this software is recommended for family physicians to enhance proper and timely patients' referral to pediatric cardiologists in order to provide better diagnostic facilities for pediatric patients who live in deprived and underserved rural areas with lack access to pediatric cardiologists.

7.
Iran J Pediatr ; 23(5): 519-24, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24800010

RESUMO

OBJECTIVE: Although there are several echocardiographic criteria, there is not yet a general consensus about the diagnosis of left ventricular noncompaction. The current criteria are mostly based on the areas with maximal noncompaction in the heart. The echocardiographer may miss this maximal point leading to a misdiagnosis. Accordingly, we suggested a new method to measure the percentage of myocardial noncompaction using two-dimensional echocardiography. METHODS: In this study, the new method was examined on 4 noncompaction and 26 dilated cardiomyopathies, and 25 normal subjects. The percentage of noncompaction was measured at 3 levels (apical, papillary muscle and mitral valve) and averaged. FINDINGS: The mean percentages of myocardial noncompaction were 3.59±2.27, 8.86±5.52 and 34.7±26.1 in the control, dilated cardiomyopathy and noncompaction groups, respectively. A value of 17% or greater could distinguish left ventricular noncompaction from dilated cardiomyopathy with 92% specificity and 100% sensitivity and from normal subjects with 100% specificity and sensitivity. This percentage had a statistically significant association with noncompacted to compacted myocardial thickness ratio (P<0.001). CONCLUSION: This method showed good correlations with the existing echocardiographic and magnetic resonance criteria. However, it is not dependent on finding the area of maximal involvement. Being comparable to magnetic resonance imaging in accuracy, it is easier to perform and more available.

8.
Iran J Pediatr ; 23(5): 593-6, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24800023

RESUMO

OBJECTIVE: Despite progresses in surgical correction of Tetralogy of Fallot, pulmonary insufficiency and progressive dysfunction of the right ventricle impress its long-term prognosis. In this study we examined the correlations between QRS duration, pulmonary insufficiency and right ventricular performance index. METHODS: We enrolled 57 repaired Tetralogy of Fallot patients. QRS duration on electrocardiogram, pulmonary regurgitation index (regurgitation time to diastolic time ratio), and right ventricular myocardial performance index were measured. FINDINGS: There was a strong inverse correlation between QRS duration and pulmonary regurgitation index. However, significant correlation did not exist between QRS duration and right ventricular myocardial performance index. QRS duration ≥160 ms predicted severe pulmonary regurgitation with 100% sensitivity and 87% specificity. CONCLUSION: Increased QRS duration can predict severity of pulmonary regurgitation.

9.
Echocardiography ; 29(8): 900-5, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22694085

RESUMO

Load independent methods should be used for the assessment of ventricular function. Debate still exists regarding whether tissue Doppler imaging (TDI) indices are influenced by preload. Here, we evaluated the effect of positive end expiratory pressure (PEEP) related preload reduction on both conventional pulsed Doppler (PD) and TDI myocardial performance index (MPI). Thirty-eight mechanically ventilated patients of 3 months to 12 years old (mean ± SD age of 30 ± 11 months) without overt heart disease were enrolled. Doppler mitral inflow velocities, isovolumetric contraction and relaxation times and aortic ejection time in addition to TDI peak systolic, early and late diastolic velocities from the basal segment of left ventricular lateral wall were determined for each patient before and after applying high PEEP (10 cmH(2) O).PD-MPI was load dependent (0.61 ± 0.22 vs. 0.78 ± 0.25, P = 0.002). However, TDI-MPI did not significantly change after the use of high PEEP declining the left ventricular volume loading (0.78 ± 0.21 vs. 0.84 ± 0.22, P = 0.23). Hence, regarding various interfering pathophysiologic factors particularly preload reduction, it seems that TDI-MPI would be a more reliable index for the assessment of ventricular function.


Assuntos
Ecocardiografia Doppler em Cores/métodos , Técnicas de Imagem por Elasticidade/métodos , Interpretação de Imagem Assistida por Computador/métodos , Respiração com Pressão Positiva , Índice de Gravidade de Doença , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/fisiopatologia , Criança , Pré-Escolar , Humanos , Lactente , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Volume Sistólico
10.
Iran J Pediatr ; 22(4): 519-23, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23430476

RESUMO

OBJECTIVE: Asphyxia-induced cardiac insult is one of the major causes of mortality and morbidity in the course of perinatal asphyxia. Nowadays, a remarkable trend of interest is sensed introducing a plausible modality for early detection of cardiac insults at the beginning stages of asphyxia. In this study we aimed to evaluate diagnostic utility of transmitral Doppler-derived parameters as well as left atrial ejection force index as a marker of left atrial contractile function in these patients. METHODS: In a prospective study selected cases of 26 asphyxiated newborns with preserved systolic function underwent conventional transmitral Doppler flow echocardiographic assessment. Left atrial ejection force index was further calculated for all patients. Data was compared with normal ranges of healthy newborns in order to clarify the diagnostic utility of these parameters for determining minor cardiac insults in this age group. FINDINGS: We found that mildly asphyxiated newborns showed an increase in the values of left atrial ejection force index (5.44±2.12 kilodyne vs. 6.66±2.17 kilodyne, P= 0.02) and left atrial filling fraction (39%±10% vs. 45%±8%, P= 0.01). Furthermore, the acceleration and deceleration rate of early filling flow peak velocity were decreased in this group of asphyxiated newborns. CONCLUSION: Assessment of left atrial ejection force in mildly asphyxiated newborns reveals that newborns with even mild asphyxia, although could not be categorized in conventional grading system, suffer to some extent from a ventricular filling abnormality. This type of latent ventricular filling abnormality could simply be unmasked by calculation of atrial ejection force index.

11.
J Tehran Heart Cent ; 7(4): 160-3, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23323076

RESUMO

BACKGROUND: Longer survival after the total repair of the Tetralogy of Fallot increases the importance of late complications such as right ventricular dysfunction. This is a prospective study of the right ventricular function in totally corrected Tetralogy of Fallot patients versus healthy children. METHODS: Thirty-two healthy children were prospectively compared with 30 totally corrected Tetralogy of Fallot patients. Right ventricular myocardial tissue velocities, right ventricular myocardial performance index, and tricuspid annular plane systolic excursion were investigated as well as the presence and severity of pulmonary regurgitation. RESULTS: The two groups were age-and sex-matched. Mean systolic peak velocity (Sa) and tricuspid annular plane systolic excursion were significantly decreased, while myocardial performance index and early to late diastolic velocity (Ea/Aa) were significantly increased in the Tetralogy of Fallot patients. Early diastolic velocity (Ea) showed no significant difference between the two groups. Sa correlated significantly with tricuspid annular plane systolic excursion in both the normal children and totally corrected Tetralogy of Fallot patients. Myocardial performance index was significantly higher in the patients with moderate to severe pulmonary regurgitation than in those with mild regurgitation. However, there was no significant correlation between this index and right ventricular myocardial tissue velocities. CONCLUSION: In this study, systolic right ventricular function indices (Sa and tricuspid annular plane systolic excursion) were impaired in the totally corrected Tetralogy of Fallot patients. Myocardial performance index was affected by the severity of pulmonary regurgitation.

12.
Ultrasound Med Biol ; 37(12): 2055-65, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22033131

RESUMO

In this article, an automatic method for detection of all chambers in apical two- and four-chamber views is proposed. The method is based on four evolving ellipses with their sizes and alignments (centre point) gradually changing through iterations until they reach to the point that approximates the chamber boundaries. The interaction between the internal, external and inter-elliptic forces controls the simultaneous evolution of ellipses. Since no prior assumption of the approximate location is required with our approach, the specialists are not required to locate the centre points of chambers in apical images, making the overall segmentation fully automated. Moreover, the resultant ellipse inside a chamber could be used as the initial contour in segmentation techniques such as active contour models, where the initial contour has a significant role for higher accuracy and faster convergence. The simplicity of equations developed in our approach make for a computationally faster algorithm, compared with former approaches that utilize morphologic operators. Our evolving ellipse does not go beyond the gaps, a problem that normally exists within boundaries in echo images, making our overall segmentation process more robust against the gaps. To evaluate the proposed method, a subset of 80 images is selected and three observers are requested to manually draw best ellipses inside the images and compare them with our results. The obtained dice coefficient results (87.62 ± 4.53% for observer-1, 83.18 ± 6.20% for observer-2, 86.02 ± 5.16% for observer-3) indicate that the proposed method has a useful performance.


Assuntos
Algoritmos , Ecocardiografia/métodos , Interpretação de Imagem Assistida por Computador/métodos , Reconhecimento Automatizado de Padrão/métodos , Inteligência Artificial , Humanos , Aumento da Imagem/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
13.
Echocardiography ; 28(10): 1088-94, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21967284

RESUMO

BACKGROUND: Progressive movement limitation in patients with Duchenne's muscular dystrophy (DMD) may mask the onset of cardiac involvement. We aimed to determine whether myocardial performance index (MPI), either by conventional Doppler (CD) or tissue Doppler imaging (TDI), could detect subclinical myocardial dysfunction in DMD patients. Furthermore, we assessed the atrial ejection force (AEF) to evaluate possible existence of latent diastolic dysfunction. METHOD: Twenty DMD patients without signs and symptoms of cardiac impairment and 20 age matched control group enrolled into the study. MPI for right ventricle and left ventricle (LV) was assessed with CD and TDI for comparison. RESULTS: No significant difference was detected in ejection fraction, fractional shortening, and AEF between two groups. CD derived MPI was higher for both ventricles in the patients (P < 0.0001). Moreover, the TDI derived MPI were significantly higher in the patients in mitral, tricuspid, and septal views (P < 0.0001). A significant decrease of mitral myocardial systolic wave velocity was detected in the patients, in favor of early involvement of the posterobasal LV myocardium. All acceleration and deceleration times' values for the late mitral inflow were higher whereas the rates were significantly lower in the patients. There was no significant difference between AEF of both groups. CONCLUSION: MPI might be a useful parameter for early detection of occult cardiac dysfunction in DMD patients when other simple and standard echocardiographic parameters are within the normal limits. Lack of atrial contribution in LV filling due to atrial contractile dysfunction may play a role in DMD cardiac dysfunction.


Assuntos
Ecocardiografia/métodos , Átrios do Coração/diagnóstico por imagem , Insuficiência Cardíaca/diagnóstico por imagem , Distrofia Muscular de Duchenne/diagnóstico por imagem , Volume Sistólico , Disfunção Ventricular Esquerda/complicações , Disfunção Ventricular Esquerda/diagnóstico por imagem , Criança , Pré-Escolar , Estudos de Viabilidade , Feminino , Insuficiência Cardíaca/complicações , Testes de Função Cardíaca/métodos , Humanos , Masculino , Distrofia Muscular de Duchenne/complicações , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
14.
Artigo em Inglês | MEDLINE | ID: mdl-21095747

RESUMO

In this paper, a fully automated method for segmenting Left Ventricle (LV) in echocardiography images is proposed. A new method named active ellipse model is developed to automatically find the best ellipse inside the LV chamber without intervention of any specialist. A modified B-Spline Snake algorithm is used to segment the LV chamber in which the initial contour is formed by the predefined ellipse. As a result of using active ellipse model, the segmentation is extricated from dealing with gaps within myocardium boundary which are highly problematic in echocardiography image segmentation. Based on the results obtained from different studies, the proposed method is faster and more accurate than previous approaches. Our method is evaluated on 20 sets of echocardiography images of patients; and acquired results (92.30 ± 4.45% dice's coefficient) indicate the proposed method has remarkable performance.


Assuntos
Algoritmos , Ecocardiografia/métodos , Ventrículos do Coração/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Modelos Biológicos , Reconhecimento Automatizado de Padrão/métodos , Disfunção Ventricular Esquerda/diagnóstico por imagem , Inteligência Artificial , Humanos , Aumento da Imagem/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
15.
Pediatr Cardiol ; 31(5): 680-8, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20383704

RESUMO

Early detection of myocardial iron overload is crucial for optimal management of patients with beta thalassemia major, which could lead to intensification of iron chelating therapy. In this study, we evaluate the conventional echocardiography and tissue Doppler imaging measurements in patients with beta thalassemia major and further introduce the assessment of atrial ejection force as a feasible price-saving approach for early detection of myocardial iron overload. During a 1-year period, 42 cases of beta thalassemia major aged <21 years and with preserved systolic function were evaluated with magnetic resonance T2* imaging (MRI T2*), conventional echocardiography, and tissue Doppler imaging techniques. Patients were classified into two groups according to their myocardial MRI T2* values, with and without critical iron loading. All patients with echocardiographic evidence of moderate and severe stages of diastolic dysfunction showed critical iron loading in their MRI T2*. After excluding those patients with severe and moderate ventricular diastolic filling abnormality, the atrial ejection force index (P = 0.002) and a number of volume indexes of the left atrium showed a significant difference between the two groups. None of the tissue Doppler imaging measurements showed a statistically significant difference between the two groups. The atrial ejection force index of 7.41, with a sensitivity of 93% and a specificity of 74%, was suggested to detect critical cardiac iron loading. These results imply that combining the atrial ejection force index with the transmitral-derived echocardiographic assessment is a feasible way to detect early stages of myocardial iron overload in patients with beta thalassemia major.


Assuntos
Átrios do Coração/fisiopatologia , Sobrecarga de Ferro/diagnóstico , Sobrecarga de Ferro/fisiopatologia , Contração Miocárdica/fisiologia , Talassemia beta/complicações , Adolescente , Quelantes/administração & dosagem , Distribuição de Qui-Quadrado , Ecocardiografia/métodos , Feminino , Humanos , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/etiologia , Imageamento por Ressonância Magnética/métodos , Masculino , Curva ROC , Sensibilidade e Especificidade , Estatísticas não Paramétricas
16.
Int J Comput Assist Radiol Surg ; 5(5): 501-13, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20232263

RESUMO

PURPOSE: A fast and robust algorithm was developed for automatic segmentation of the left ventricular endocardial boundary in echocardiographic images. The method was applied to calculate left ventricular volume and ejection fraction estimation. METHODS: A fast adaptive B-spline snake algorithm that resolves the computational concerns of conventional active contours and avoids computationally expensive optimizations was developed. A combination of external forces, adaptive node insertion, and multiresolution strategy was incorporated in the proposed algorithm. Boundary extraction with area and volume estimation in left ventricular echocardiographic images was implemented using the B-spline snake algorithm. The method was implemented in MATLAB and 50 medical images were used to evaluate the algorithm performance. Experimental validation was done using a database of echocardiographic images that had been manually evaluated by experts. RESULTS: Comparison of methods demonstrates significant improvement over conventional algorithms using the adaptive B-spline technique. Moreover, our method reached a reasonable agreement with the results obtained manually by experts. The accuracy of boundary detection was calculated with Dice's coefficient equation (91.13%), and the average computational time was 1.24 s in a PC implementation. CONCLUSION: In sum, the proposed method achieves satisfactory results with low computational complexity. This algorithm provides a robust and feasible technique for echocardiographic image segmentation. Suggestions for future improvements of the method are provided.


Assuntos
Algoritmos , Simulação por Computador , Ecocardiografia/métodos , Endocárdio/diagnóstico por imagem , Ventrículos do Coração/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Volume Cardíaco/fisiologia , Humanos
17.
Comput Methods Programs Biomed ; 99(1): 43-8, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20036439

RESUMO

In this paper, we propose a novel method for pediatric heart sounds segmentation by paying special attention to the physiological effects of respiration on pediatric heart sounds. The segmentation is accomplished in three steps. First, the envelope of a heart sounds signal is obtained with emphasis on the first heart sound (S(1)) and the second heart sound (S(2)) by using short time spectral energy and autoregressive (AR) parameters of the signal. Then, the basic heart sounds are extracted taking into account the repetitive and spectral characteristics of S(1) and S(2) sounds by using a Multi-Layer Perceptron (MLP) neural network classifier. In the final step, by considering the diastolic and systolic intervals variations due to the effect of a child's respiration, a complete and precise heart sounds end-pointing and segmentation is achieved.


Assuntos
Auscultação Cardíaca/métodos , Ruídos Cardíacos , Criança , Bases de Dados Factuais , Eletrocardiografia/métodos , Humanos , Processamento de Sinais Assistido por Computador
18.
Artigo em Inglês | MEDLINE | ID: mdl-19964311

RESUMO

Left ventricular (LV) mass has several important diagnostic and indicative implications. In this paper, a fast and accurate technique for detection of inner and outer boundaries of LV and, consequently, calculation of LV mass from apical 4-chamber echocardiographic images is presented. For detection of the inner boundary, a modified B-spline snake is proposed, which relies merely on image intensity and obviates the need for computationally-demanding image forces. The outer boundary is then obtained using a Markov random fields model in the neighborhood of the estimated inner border. Experimental validation of the proposed technique demonstrates remarkable improvement over conventional algorithms.


Assuntos
Ecocardiografia/métodos , Endocárdio/patologia , Ventrículos do Coração/patologia , Algoritmos , Automação , Biologia Computacional/métodos , Simulação por Computador , Ecocardiografia/instrumentação , Humanos , Processamento de Imagem Assistida por Computador , Cadeias de Markov , Modelos Cardiovasculares , Reconhecimento Automatizado de Padrão/métodos , Reprodutibilidade dos Testes , Processamento de Sinais Assistido por Computador , Software
19.
Cardiol Young ; 19(6): 580-8, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19849873

RESUMO

Our aim was further to clarify the diagnostic usefulness of N-terminal pro-B-type natriuretic peptide for detecting ventricular dysfunction in children, and its correlation with myocardial performance index and New York University Pediatric Heart Failure Index score. We also hypothesized that the level of this natriuretic peptide in the serum could predict the severity of diastolic abnormalities in children with cardiac failure. We enrolled 99 patients, aged from 3 months to 16 years, who had been referred for echocardiography to evaluate ventricular function. Echocardiographic evidence of left ventricular systolic and diastolic dysfunction was found in 20 and 42 patients, respectively. We classified these patients as having impaired relaxation, seen in 12 patients, pseudonormal patterns seen in 19 patients, and restrictive-like patterns of filling seen in 11 patients. The mean of the log-transformed values for N-terminal pro-B-type natriuretic peptide increased significantly according to the severity of diastolic dysfunction (p = 0.003, p = 0.022, p < 0.0001). A value of 178 pg/ml had a sensitivity of 88% and specificity of 81% for detecting abnormal diastolic function (p < 0.0001). Furthermore, the log-transformed values correlated with myocardial performance index (p < 0.0001) in a positive manner, and the levels increased significantly according to New York University Pediatric Heart Failure Index score, showing a linear correlation with a robust r value for regression (r = 0.89, p < 0.0001). Our findings suggest that higher levels of the peptide, having a good correlation with New York University Pediatric Heart Failure Index score and myocardial performance index, might be a suitable marker to rule out ventricular diastolic dysfunction in children.


Assuntos
Peptídeo Natriurético Encefálico/sangue , Disfunção Ventricular/sangue , Adolescente , Análise de Variância , Área Sob a Curva , Biomarcadores/sangue , Criança , Pré-Escolar , Diástole , Ecocardiografia/métodos , Feminino , Humanos , Lactente , Modelos Lineares , Masculino , Valor Preditivo dos Testes , Estudos Prospectivos , Curva ROC , Sensibilidade e Especificidade , Disfunção Ventricular/diagnóstico por imagem
20.
Cardiol Young ; 19(5): 501-6, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19703336

RESUMO

We aimed to determine the effect of supplementation with coenzyme Q10 on conventional therapy of children with cardiac failure due to idiopathic dilated cardiomyopathy. In a prospective, randomized, double-blinded, placebo-controlled trial, we randomized 38 patients younger than 18 years with idiopathic dilated cardiomyopathy to receive either coenzyme Q10, chosen for 17 patients, or placebo, administered in the remaining 21. Echocardiographic systolic and diastolic function parameters were determined for every patient at baseline, and after 6 months of supplementation. The index score for cardiac failure in children as established in New York was used for assessing the functional class of the patients. After 6 months supplementation, 10 patients randomized to receive coenzyme Q10 showed improvements in the grading of diastolic function, this being significantly more than that achieved by those randomized to the placebo group (p value = 0.011). The mean score for the index of cardiac failure index for those receiving coenzyme Q10 was also lower than the control group (p value = 0.024).Our results, therefore, indicate that administration of coenzyme Q10 is useful in ameliorating cardiac failure in patients with idiopathic dilated cardiomyopathy through its significant effect on improving diastolic function.


Assuntos
Cardiomiopatia Dilatada/complicações , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/etiologia , Ubiquinona/análogos & derivados , Vitaminas/uso terapêutico , Adolescente , Criança , Pré-Escolar , Método Duplo-Cego , Humanos , Lactente , Estudos Prospectivos , Ubiquinona/uso terapêutico
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