Smartphone-Based Screening for Cardiovascular Diseases: A Trend?

Abstract Cardiovascular diseases are the leading cause of death in the world. People living in vulnerable and poor places such as slums, rural areas and remote locations have difficulty in accessing medical care and diagnostic tests. In addition, given the COVID-19 pandemic, we are witnessing an increase in the use of telemedicine and non-invasive tools for monitoring vital signs. These questions motivate us to write this point of view and to describe some of the main innovations used for non-invasive screening of heart diseases. Smartphones are widely used by the population and are perfect tools for screening cardiovascular diseases. They are equipped with camera, flashlight, microphone, processor, and internet connection, which allow optical, electrical, and acoustic analysis of cardiovascular phenomena. Thus, when using signal processing and artificial intelligence approaches, smartphones may have predictive power for cardiovascular diseases. Here we present different smartphone approaches to analyze signals obtained from various methods including photoplethysmography, phonocardiograph, and electrocardiography to estimate heart rate, blood pressure, oxygen saturation (SpO2), heart murmurs and electrical conduction. Our objective is to present innovations in non-invasive diagnostics using the smartphone and to reflect on these trending approaches. These could help to improve health access and the screening of cardiovascular diseases for millions of people, particularly those living in needy areas.

Herramienta para la detección automática de nódulos pulmonares solitarios en series de imágenes de tomografía computarizada multicorte / A tool for automated detection of solitary pulmonary nodules in series of multicut computerized tomography images

Introducción: el nódulo pulmonar solitario es uno de los problemas más frecuentes en la práctica del radiólogo, que constituye un hallazgo incidental habitual en los estudios torácicos realizados durante el ejercicio clínico diario. Objetivo: implementar un sistema de diagnóstico asistido por computadora que facilite la detección del nódulo pulmonar solitario en las series de imágenes de tomografía computarizada multicorte. Métodos: se utilizó Matlab para el desarrollo y evaluación de un conjunto de algoritmos que constituyen elementos necesarios de un sistema de diagnóstico asistido por computadora. En orden: un algoritmo para la extracción de las regiones de interés, algoritmo para la extracción de características y un algoritmo de detección de nódulo pulmonar solitario para el cual se probaron varios clasificadores. La evaluación de los algoritmos fue efectuada en base a las anotaciones realizada por especialistas a la colección de imágenes LIDC-IDRI (Lung Image Database Consortium). Resultados: el método de segmentación empleado para extracción de las regiones de interés permitió generar la adecuada división de las imágenes originales en regiones significativas. El algoritmo utilizado en la detección mostró para el conjunto de prueba además de buena exactitud (de 96,4 por ciento), un buen balance de sensibilidad (91,5 por ciento) para una tasa de 0,84 falsos positivos por imagen. Conclusiones: el trabajo de investigación y la implementación realizada se reflejan en la construcción de una interfaz gráfica en Matlab como prototipo del sistema de diagnóstico asistido por computadora, con el que se puede contribuir a detectar más fácilmente el NPS(AU)

Introduction: solitary pulmonary nodules are one of the most frequent problems in radiographic practice. They are a common incidental finding in chest studies conducted during routine clinical work. Objective: implement a computer-assisted diagnostic system facilitating detection of solitary pulmonary nodules in multicut computerized tomography image series. Methods: Matlab was used to develop and evaluate a set of algorithms constituting necessary components of a computer-assisted diagnostic system. The order was the following: an algorithm to extract regions of interest, another to extract characteristics, and another to detect solitary pulmonary nodules, for which several classifiers were tested. Evaluation of the algorithms was based on notes taken by specialists on the LIDC-IDRI (Lung Image Database Consortium) image collection. Results: the segmentation method used for extraction of regions of interest made it possible to create a suitable division of the original images into significant regions. The algorithm used for detection found that the test set exhibited good accuracy (96.4%), a good sensitivity balance (91.5%), and a 0.84 rate of false positives per image. Conclusions: the research and implementation work done is reflected in the construction of a Matlab graphic interface serving as a prototype for a computer-assisted diagnostic system which may facilitate detection of SPNs.

Automatic segmentation of brain tumors in magnetic resonance imaging / Segmentação automática de tumores cerebrais em imagens de ressonância magnética

ABSTRACT Objective To develop a computational algorithm applied to magnetic resonance imaging for automatic segmentation of brain tumors. Methods A total of 130 magnetic resonance images were used in the T1c, T2 and FSPRG T1C sequences and in the axial, sagittal and coronal planes of patients with brain cancer. The algorithms employed contrast correction, histogram normalization and binarization techniques to disconnect adjacent structures from the brain and enhance the region of interest. Automatic segmentation was performed through detection by coordinates and arithmetic mean of the area. Morphological operators were used to eliminate undesirable elements and reconstruct the shape and texture of the tumor. The results were compared with manual segmentations by two radiologists to determine the efficacy of the algorithms implemented. Results The correlated correspondence between the segmentation obtained and the gold standard was 89.23%. Conclusion It is possible to locate and define the tumor region automatically with no the need for user interaction, based on two innovative methods to detect brain extreme sites and exclude non-tumor tissues on magnetic resonance images.

RESUMO Objetivo Desenvolver um algoritmo computacional aplicado a imagens de ressonância magnética, para segmentação automática de tumores cerebrais. Métodos Foram utilizadas 130 imagens de ressonância magnética nas sequências T1c, T2 e FSPRG T1c e nos planos axial, sagital e coronal de pacientes acometidos com câncer cerebral. Os algoritmos empregaram técnicas de correção de contraste, normalização de histograma e binarização, para desconectar estruturas adjacentes do cérebro e realçar a região de interesse. A segmentação automática foi realizada por meio da detecção por coordenadas e por média aritmética da área. Operadores morfológicos foram utilizados para eliminar elementos indesejáveis e reconstruir a forma e a textura do tumor. Os resultados foram comparados com as segmentações manuais de dois médicos radiologistas, para determinar a eficácia dos algoritmos implementados. Resultados Os acertos foram de 89,23% na correspondência entre a segmentação obtida e o padrão-ouro. Conclusão É possível localizar e delimitar a região tumoral de forma automática, sem necessidade de interação com o usuário baseado em dois métodos inovadores de detecção dos extremos do cérebro e de exclusão dos tecidos não tumorais em imagens de ressonância magnética.

Evaluation of the color vision acuity pattern of undergraduates of health courses in a Brazilian university / Avaliação do padrão de acuidade visual para cores de acadêmicos da área de saúde em Universidade brasileira

ABSTRACT Objective: The goal of the study is to analyze the color vision acuity pattern in undergraduates of health courses and to discuss the impact of these diseases in this population. Color deficiencies interfere significantly in the daily routine of professionals in the health area who need to discern different color hues in several situations of their everyday practice. Methods: Sixty-four volunteers, undergraduates of health courses of the Federal University of Alfenas (UNIFAL-MG), participated in the study. One man was excluded because he did not fit the inclusion criteria. Two groups were analyzed according to sex with the Farnsworth Munsell 100-Hue test. Results: There were no significant differences between the eyes and between the groups analyzed. The color vision acuity pattern is between 35 and 40, according to the Total Error Score. The gender issue does not influence the general pattern of the color vision acuity of the health courses undergraduates when those with color vision disorders are removed. Conclusion: Screenings and guidance should be given to undergraduates of health courses so that, aware of their condition of presenting some type of color disorder, they shall make the appropriate decision on which career to follow so that such limitation does not interfere with the quality of their daily life.

RESUMO Objetivo: O objetivo do estudo é analisar a acuidade visual média para cores de estudantes da área de saúde e discutir o impacto das doenças que a afetam nessa população. Deficiências cromáticas interferem de forma significativa no dia a dia de profissionais da área da saúde que necessitam de discernir diferentes matizes em diversas situações de sua prática profissional. Métodos: Participaram da pesquisa 64 voluntários, estudantes de cursos da área de saúde da Universidade Federal de Alfenas, sendo que 1 homem foi excluído por não se adequar aos critérios de inclusão. Dois grupos foram analisados, de acordo com o sexo, com o teste de Farnsworth Munsell 100-Hue. Resultados: Não houve diferenças significativas entre os olhos e entre os grupos analisados. O padrão de visão de cores encontra-se entre 35 e 40, de acordo com a Pontuação do Erro Total. A questão de gênero não influencia no padrão geral da qualidade de visão de cores de estudantes da área de saúde, quando retirados aqueles que apresentam distúrbios da visão cromática. Conclusão: Devem ser realizadas triagens e orientação para estudantes de cursos da área de saúde para que, cientes da sua condição de apresentar algum tipo de distúrbio cromático, possam tomar a decisão adequada sobre qual carreira seguir para que tal limitação não interfira na qualidade de sua vida diária.

Multimodal quantitative magnetic resonance imaging analysis with individualized postprocessing in patients with drug-resistant focal epilepsy and conventional visual inspection negative for epileptogenic lesions

OBJECTIVES: Approximately one-third of candidates for epilepsy surgery have no visible abnormalities on conventional magnetic resonance imaging. This is extremely discouraging, as these patients have a less favorable prognosis. We aimed to evaluate the utility of quantitative magnetic resonance imaging in patients with drug-resistant neocortical focal epilepsy and negative imaging. METHODS: A prospective study including 46 patients evaluated through individualized postprocessing of five quantitative measures: cortical thickness, white and gray matter junction signal, relaxation rate, magnetization transfer ratio, and mean diffusivity. Scalp video-electroencephalography was used to suggest the epileptogenic zone. A volumetric fluid-attenuated inversion recovery sequence was performed to aid visual inspection. A critical assessment of follow-up was also conducted throughout the study. RESULTS: In the subgroup classified as having an epileptogenic zone, individualized postprocessing detected abnormalities within the region of electroclinical origin in 9.7% to 31.0% of patients. Abnormalities outside the epileptogenic zone were more frequent, up to 51.7%. In five patients initially included with negative imaging, an epileptogenic structural abnormality was identified when a new visual magnetic resonance imaging inspection was guided by information gleaned from postprocessing. In three patients, epileptogenic lesions were detected after visual evaluation with volumetric fluid-attenuated sequence guided by video electroencephalography. CONCLUSION: Although quantitative magnetic resonance imaging analyses may suggest hidden structural lesions, caution is warranted because of the apparent low specificity of these findings for the epileptogenic zone. Conversely, these methods can be used to prevent visible lesions from being ignored, even in referral centers. In parallel, we need to highlight the positive contribution of the volumetric fluid-attenuated sequence.

Disease activity is associated with LV dysfunction in rheumatoid arthritis patients without clinical cardiovascular disease

Abstract Objectives: The cross-sectional study aimed to assess left ventricular systolic function using global longitudinal strain (GLS) by speckle-tracking echocardiography (STE) and arterial stiffness using cardio-ankle vascular index (CAVI) in Thai adults with rheumatoid arthritis (RA) and no clinical evidence of cardiovascular disease (CVD). Methods: Confirmed RA patients were selected from a list of outpatient attendees if they were 18 years (y) without clinical, ECG and echocardiographic evidence of CVD, diabetes mellitus, chronic kidney disease, and excess alcoholic intake. Controls were matched with age and sex to a list of healthy individuals with normal echocardiograms. All underwent STE and CAVI. Results: 60 RA patients (females = 55) were analysed. Mean standard deviation of patient and control ages were 50 ± 10.2 and 51 ±9.9 y, respectively, and mean duration of RA was 9.0 ± 6.8 y. Mean DAS28-CRP and DAS28-ESR were 2.9 ± 0.9 and 3.4 ± 0.9, respectively. There was no between-group differences in left ventricular ejection fraction (LVEF), LV sizes, LVMI, LV diastolic function and CAVI were within normal limits but all GLSs values was significantly lower in patients vs. controls: 17.6 ± 3.4 vs 20.4 ± 2.2 (p = 0.03). Multivariate regression analysis demonstrated significant correlations between GLSs and RA duration (p = 0.02), and GLSs and DAS28-CRP (p = 0.041). Conclusions: Patients with RA and no clinical CV disease have reduced LV systolic function as shown by lower GLSs. It is common and associated with disease activity and RA disease duration. 2D speckle-tracking GLSs is robust in detecting this subclinical LV systolic dysfunction.

Features of Undiagnosed Breast Cancers at Screening Breast MR Imaging and Potential Utility of Computer-Aided Evaluation

OBJECTIVE: To retrospectively evaluate the features of undiagnosed breast cancers on prior screening breast magnetic resonance (MR) images in patients who were subsequently diagnosed with breast cancer, as well as the potential utility of MR-computer-aided evaluation (CAE). MATERIALS AND METHODS: Between March 2004 and May 2013, of the 72 consecutive pairs of prior negative MR images and subsequent MR images with diagnosed cancers (median interval, 32.8 months; range, 5.4-104.6 months), 36 (50%) had visible findings (mean size, 1.0 cm; range, 0.3-5.2 cm). The visible findings were divided into either actionable or underthreshold groups by the blinded review by 5 radiologists. MR imaging features, reasons for missed cancer, and MR-CAE features according to actionability were evaluated. RESULTS: Of the 36 visible findings on prior MR images, 33.3% (12 of 36) of the lesions were determined to be actionable and 66.7% (24 of 36) were underthreshold; 85.7% (6 of 7) of masses and 31.6% (6 of 19) of non-mass enhancements were classified as actionable lesions. Mimicking physiologic enhancements (27.8%, 10 of 36) and small lesion size (27.8%, 10 of 36) were the most common reasons for missed cancer. Actionable findings tended to show more washout or plateau kinetic patterns on MR-CAE than underthreshold findings, as the 100% of actionable findings and 46.7% of underthreshold findings showed washout or plateau (p = 0.008). CONCLUSION: MR-CAE has the potential for reducing the number of undiagnosed breast cancers on screening breast MR images, the majority of which are caused by mimicking physiologic enhancements or small lesion size.

A computerized system for the application of Basso, Beattie and Bresnahan scale in Wistar rats

OBJECTIVES: To develop and test a computer program to assist researchers in assigning scores in the application of the Basso, Beattie and Bresnahan (BBB) scale and to compare these scores when doing so in free, targeted and automated computer-assisted modes. METHOD: To test the program, the participants used the Impactor methodology recommended by the New York University (USA), in which 12 Wistar rats submitted to spinal cord injury were filmed on the 28th day after the injury. Eight researchers from the Laboratory of Medical Investigation, Faculdade de Medicina da Universidade de São Paulo, SP, Brazil took part in the study. The two heads of the laboratory, with 15 years of experience in the application of the scale, were considered the gold standard. RESULTS: The results of the scale application were not significantly different in relation to the gold standard, considering the mean of the evaluators in each method: free, targeted and automated form (with the help of the computer). CONCLUSIONS: The application of the BBB scale in the automated mode, using the computer program, did not present any difference in relation to the gold standard for all the evaluators. Level of Evidence II, Diagnostic Studies. .

Blood Pressure and Hemodynamic Adaptations after a Training Program in Young Individuals with Down Syndrome / Pressão Arterial e Adaptações Hemodinâmicas após Programa de Treinamento em Jovens com Síndrome de Down

Background: Cardiovascular diseases affect people worldwide. Individuals with Down Syndrome (DS) have an up to sixteen-time greater risk of mortality from cardiovascular diseases. Objective: To evaluate the effects of aerobic and resistance exercises on blood pressure and hemodynamic variables of young individuals with DS. Methods: A total of 29 young individuals with DS participated in the study. They were divided into two groups: aerobic training (AT) (n = 14), and resistance training (TR) (n = 15). Their mean age was 15.7 ± 2.82 years. The training program lasted 12 weeks, and had a frequency of three times a week for AT and twice a week for RT. AT was performed in treadmill/ bicycle ergometer, at an intensity between 50%-70% of the HR reserve. RT comprised nine exercises with three sets of 12 repetition-maximum. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP) and hemodynamic variables were assessed beat-to-beat using the Finometer device before/after the training program. Descriptive analysis, the Shapiro-Wilk test to check the normality of data, and the two-way ANOVA for repeated measures were used to compare pre- and post-training variables. The Pearson’s correlation coefficient was calculated to correlate hemodynamic variables. The SPSS version 18.0 was used with the significance level set at p < 0.05. Results: After twelve weeks of aerobic and/or resistance training, significant reductions in variables SBP, DBP and MBP were observed. Conclusion: This study suggests a chronic hypotensive effect of moderate aerobic and resistance exercises on young individuals with DS. .

Fundamento: As doenças cardiovasculares atingem as pessoas em todo o mundo. Pessoas com Síndrome de Down (SD) apresentam um risco até dezesseis vezes maior de mortalidade por doenças cardiovasculares. Objetivo: Avaliar os efeitos do exercício aeróbio e resistido na pressão arterial e variáveis hemodinâmicas de jovens com SD. Métodos: Participaram do estudo 29 jovens com SD, divididos em dois grupos: (TA) Treinamento Aeróbio (n = 14) e (TR) Treinamento Resistido (n = 15), idade 15,7 ± 2,82 anos. O programa de treinamento teve doze semanas, frequência de três vezes por semana para TA, e duas vezes, para TR. TA foi realizado com esteira/bicicleta, intensidade entre 50%-70% da FC de reserva. TR teve nove exercícios com três séries de doze repetições máximas. Avaliações de Pressão Arterial Sistólica (PAS), Pressão Arterial Diastólica PAD), Pressão Arterial Média (PAM) e variáveis hemodinâmicas foram realizadas batimento a batimento por meio do Finometer antes/após o programa de treinamento. Foram usados estatística descritiva, teste de Shapiro-Wilk para verificação da normalidade dos dados e teste ANOVA two-way para medidas repetidas para a comparação das variáveis pré e pós-treinamento. Para correlacionar as variáveis hemodinâmicas, foi calculado o coeficiente de correlação de Pearson. Utilizou-se o programa estatístico SPSS versão 18.0, adotando nível de significância (p < 0,05). Resultados: Após doze semanas de treinamento, aeróbio e/ou resistido, ocorreram reduções significativas pós‑intervenção nas variáveis de PAS, PAD e PAM. Conclusão: Sugere um efeito hipotensivo crônico do exercício aeróbio e resistido moderado em jovens com SD. .

Gestational Age-specific Cut-off Values Are Needed for Diagnosis of Subclinical Hypothyroidism in Early Pregnancy

During the first trimester of pregnancy, thyroid-stimulating hormone (TSH) >2.5 mIU/L has been suggested as the universal criterion for subclinical hypothyroidism. However, TSH levels change continuously during pregnancy, even in the first trimester. Therefore the use of a fixed cut-off value for TSH may result in a different diagnosis rate of subclinical hypothyroidism according to gestational age. The objective of this study was to obtain the normal reference range of TSH during the first trimester in Korean gravida and to determine the diagnosis rate of subclinical hypothyroidism using the fixed cut-off value (TSH >2.5 mIU/L). The study population consisted of pregnant women who were measured for TSH during the first trimester of pregnancy (n=492) and nonpregnant women (n=984). Median concentration of TSH in pregnant women was lower than in non-pregnant women. There was a continuous decrease of median TSH concentration during the first trimester of pregnancy (median TSH concentration: 1.82 mIU/L for 3+0 to 6+6 weeks; 1.53 mIU/L for 7+0 to 7+6 weeks; and 1.05 mIU/L for 8+0 to 13+6 weeks). Using the fixed cut-off value of TSH >2.5 mIU/L, the diagnosis rate of subclinical hypothyroidism decreased significantly according to the gestational age (GA) at TSH (25% in 3+0 to 6+6 weeks, 13% in 7+0 to 7+6 weeks, and 9% for 8+0 to 13+6 weeks, P<0.001), whereas the diagnosis rate was 5% in all GA with the use of a GA-specific cut-off value (P=0.995). Therefore, GA-specific criteria might be more appropriate for the diagnosis of subclinical hypothyroidism.

Computational Discrimination of Breast Cancer for Korean Women Based on Epidemiologic Data Only

Breast cancer is the second leading cancer for Korean women and its incidence rate has been increasing annually. If early diagnosis were implemented with epidemiologic data, the women could easily assess breast cancer risk using internet. National Cancer Institute in the United States has released a Web-based Breast Cancer Risk Assessment Tool based on Gail model. However, it is inapplicable directly to Korean women since breast cancer risk is dependent on race. Also, it shows low accuracy (58%-59%). In this study, breast cancer discrimination models for Korean women are developed using only epidemiological case-control data (n = 4,574). The models are configured by different classification techniques: support vector machine, artificial neural network, and Bayesian network. A 1,000-time repeated random sub-sampling validation is performed for diverse parameter conditions, respectively. The performance is evaluated and compared as an area under the receiver operating characteristic curve (AUC). According to age group and classification techniques, AUC, accuracy, sensitivity, specificity, and calculation time of all models were calculated and compared. Although the support vector machine took the longest calculation time, the highest classification performance has been achieved in the case of women older than 50 yr (AUC = 64%). The proposed model is dependent on demographic characteristics, reproductive factors, and lifestyle habits without using any clinical or genetic test. It is expected that the model could be implemented as a web-based discrimination tool for breast cancer. This tool can encourage potential breast cancer prone women to go the hospital for diagnostic tests.

Application of a Novel Diagnostic Rule in the Differential Diagnosis between Acute Gouty Arthritis and Septic Arthritis

Septic arthritis and gout are major diseases that should be suspected in patients with acute monoarthritis. These two diseases are clinically similar and often indistinguishable without the help of synovial fluid analysis. Recently, a novel diagnostic rule for gout without synovial fluid analysis was developed and showed relevant performances. This study aimed to determine whether this diagnostic rule could perform well in distinguishing gout from septic arthritis. The diagnostic rule comprises 7 clinical and laboratory variables, each of which is given a specified score. The probability of gout is classified into 3 groups according to the sum of the scores: high (> or = 8), intermediate (> 4 to < 8) and low probability (< or = 4). In this retrospective study, we applied this diagnostic rule to 136 patients who presented as acute monoarthritis and were subsequently diagnosed as acute gout (n = 82) and septic arthritis (n = 54) based on synovial fluid analysis. The mean sum of scores of acute gout patients was significantly higher than that of those with septic arthritis (8.6 +/- 0.2 vs. 3.6 +/- 0.32, P < 0.001). Patients with acute gout had significantly more 'high', and less 'low' probabilities compared to those with septic arthritis (Eta[eta]: 0.776). The prevalence of acute gouty arthritis, as confirmed by the presence of monosodium crystal, was 95.5% (61/64), 57.5% (19/33), and 5.1% (2/39) in high, intermediate and low probability group, respectively. The recently introduced diagnostic rule properly discriminates acute gout from septic arthritis. It may help physicians diagnose gout in cases difficult to be differentiated from septic arthritis.

Using ImageJ to Evaluate Optic Disc Pallor in Traumatic Optic Neuropathy

PURPOSE: To evaluate optic disc pallor using ImageJ in traumatic optic neuropathy (TON). METHODS: This study examined unilateral TON patients. The optic disc was divided into 4 quadrants (temporal, superior, nasal, and inferior), consistent with the quadrants on optical coherence tomography (OCT) retinal nerve fiber layer (RNFL) thickness maps. Optic disc photography was performed and disc pallor was quantified using gray scale photographic images imported into ImageJ software. The correlation between optic disc pallor and RNFL thickness was examined in each quadrant. RESULTS: A total of 35 patients (31 male, 4 female) were enrolled in the study. The mean participant age was 34.8 +/- 15.0 years (range, 5 to 63 years). Overall RNFL thickness decreased in 6 patients, with thinning most often occurring in the inferior quadrant (28 of 35 eyes). There was a significant correlation between optic disc pallor and RNFL thickness (superior, rho = -0.358, p = 0.04; inferior, rho = -0.345, p = 0.04; nasal, rho = -0.417, p = 0.01; temporal, rho = -0.390, p = 0.02). The highest level of correspondence between disc pallor and RNFL thickness values outside of the normative 95th percentiles was 39.3% and occurred in the inferior quadrant. CONCLUSIONS: Optic disc pallor in TON was quantified with ImageJ and was significantly correlated with RNFL thickness abnormalities. Thus, ImageJ evaluations of disc pallor may be useful for evaluating RNFL thinning, as verified by OCT RNFL analyses.

Caracterização do perfil da micro-alternância da onda T na cardiomiopatia hipertrófica / Characterization of the profile of microvolt T-wave alternans in hypertrophic cardiomyopathy

Introdução: A cardiomiopatia hipertrófica (CMH) é definida, como a hipertrofia miocárdica ocorrida na ausência de doença cardíaca ou sistêmica, sendo a mais prevalente das cardiopatias de transmissão genética e a principal causa de morte súbita em jovens e atletas. A única opção de tratamento para prevenção dessa complicação é a indicação do cardiodesfibrilador implantável (CDI). Alguns marcadores de risco foram identificados, como: pacientes que sobreviveram à parada cardíaca por fibrilação ventricular, episódio de taquicardia ventricular sustentada; história familiar precoce de MSC; síncope inexplicada; espessura septal >= 30 mm; taquicardia ventricular não sustentada (TVNS) no Holter; queda da pressão sistólica (PAS) > 20 mmHg ou aumento < 20 mmHg no esforço. Entretanto, a sensibilidade e especificidade desses critérios são limitadas, tornando necessário o conhecimento de novos métodos diagnósticos com capacidade de predizer MSC. A micro-alternância da onda T (MAOT) é utilizada como ferramenta diagnóstica na estratificação de pacientes com riscos de desenvolver arritmias ventriculares malignas e MSC auxiliando na indicação do CDI. Na CMH há poucos estudos realizados com objetivos e resultados diferentes e, atualmente, uma nova metodologia na realização desses exames foi desenvolvida, não sendo testada nesta população. Os objetivos do presente estudo foram: caracterizar os valores da MAOT pela metodologia Média Móvel Modificada (MMM) e avaliar a associação de seus resultados com os fatores de risco clínicos para MSC. Metodologia: Foram selecionados 132 pacientes com CMH que foram divididos em dois grupos: 1) Alto Risco, 67 pacientes, que apresentavam, pelo menos, um fator de risco para morte súbita cardíaca (história familiar de morte súbita; síncope inexplicada; espessura septal do miocárdio >=30 mm; taquicardia ventricular não sustentada; queda da pressão sistólica no teste de esforço)...

Introduction: Hypertrophic cardiomyopathy (HCM) is defined as the myocardial hypertrophy in the absence of cardiac or systemic disease, being the most common genetic transmission cardiopathy and responsible for sudden cardiac death (SCD) in young adults and athletes. The first-line treatment option for prevention of SCD is the implantable cardioverter-defibrillator (ICD). Some clinical factors have been identified as high risk for the occurrence of SCD: history of cardiac resuscitation for ventricular fibrillation, episode of sustained ventricular tachycardia, family history of premature SCD, unexplained syncope, ventricular septal thickness >= 30 mm; nonsustained ventricular tachycardia (NSVT) in Holter and inadequate response of blood pressure to exercise: decrease in systolic blood pressure (SBP) > 20 mmHg or increase < 20 mmHg during effort. These criteria, however, are limited in sensitivity and specificity and new diagnostic methods have been required. The microvolt T-wave alternans (MTWA) is used as a diagnostic tool to identify high-risk patients predisposed to malignant ventricular arrhythmias and SCD. Therefore, MTWA may be helpful to indicate ICD. There are no reports in the literature concerning the use of MTWA in HCM. This research aims to evaluate the values of MTWA by modified moving average (MMA) method and the association with clinical factors for SCD. Methods: We enrolled 132 patients with HCM that were divided into two groups: 1) High Risk (HR) group, 67 patients, that had at least one risk factor for sudden cardiac death (family history of SCD; unexplained syncope; ventricular septal thickness >= 30 mm; nonsustained ventricular tachycardia; inadequate response of blood pressure to exercise) and 2) Low Risk (LR) group, 65 patients, without risk factors. The most participants were male (63%) and their mean age was 37 (± 11.3) years...

Digital Tomosynthesis of the Chest: Comparison of Patient Exposure Dose and Image Quality between Standard Default Setting and Low Dose Setting

OBJECTIVE: To determine the optimum low dose (LD) digital tomosynthesis (DT) setting, and to compared the image quality of the LD DT with that of the standard default (SD) DT. MATERIALS AND METHODS: Nine DT settings, by changing tube voltage, copper filter, and dose ratio, were performed for determining the LD setting. Among combinations of DT setting, a condition providing the lowest radiation dose was determined. Eighty artificial nodules less than 1 cm in diameter (subcentimeter nodules: 40, micronodules less than 4 mm: 40) were attached to a Styrofoam and a diaphragm of the phantom. Among these, 38 nodules were located at the periphery of the lung (thin area) and 42 nodules were located at the paravertebral or sub-diaphragmatic area (thick area). Four observers counted the number of nodules detected in the thick and thin areas. The detection sensitivity in SD and LD settings were calculated separately. Data were analyzed statistically. RESULTS: The lowest LD setting was a combination of 100 kVp, 0.3 mm additional copper filter, and a 1 : 5 dose ratio. The effective dose for the LD and SD settings were 62 microSv and 140 microSv, separately. A 56.7% dose reduction was achieved in the LD setting compared with the SD setting. Detection sensitivities were not different between the SD and the LD settings except between observers 1 and 2 for the detection of micronodules in the thick area. CONCLUSION: LD DT can be effective in nodule detection bigger than 4 mm without a significant decrease in image quality compared with SD DT.

A Novel Computerized Visual Acuity Test for Children

PURPOSE: To investigate the efficacy of a computerized visual acuity test, the SNU visual acuity test for children. METHODS: Fifty-six children, ranging from 1 to 5 years of age, were included. In a dark room, children gazed at and followed a circular dot with 50% contrast moving at a fixed velocity of 10 pixels/sec on a computer monitor. Eye movement was captured using a charge coupled device camera and was expressed as coordinates on a graph. Movements of the eye and dot were superimposed on a graph and analyzed. Minimum visualized dot diameters were compared to the Teller visual acuity. RESULTS: Ten eyes (8.9%) of six children failed to perform the Teller visual acuity test, and two eyes (1.8%) of one patient failed to perform the SNU visual acuity test. The observed Teller visual acuity and SNU visual acuity were significantly correlated (p < 0.001). Visual angle degrees converted from the Teller visual acuity and SNU visual acuity were also significantly correlated (p < 0.001). CONCLUSION: The SNU visual acuity using moving targets correlated well with Teller visual acuity and was more applicable than the Teller acuity test. Therefore, the SNU visual acuity test has potential clinical applications for children.

Análise do desempenho de um eletrocardiógrafo interpretativo para utilização em um sistema computacional de auxílio diagnóstico em síndromes coronarianas agudas / Performance analysis of an interpretive electrocardiograph for use in a computer-aided diagnostic system for acute coronary syndromes

O eletrocardiograma  (ECG) registra a atividade elétrica cardíaca de forma não invasiva e permite obter uma avaliação rápida do ritmo cardíaco, muito útil na definição da conduta terapêutica imediata em pacientes com suspeita de síndrome coronariana aguda  (SCA), que é uma entidade clínica que engloba a angina instável e os infartos agudos do miocárdio com e sem supra-desnível do segmento  ST. Atualmente, eletrocardiógrafos de diversos fabricantes são capazes de fornecer diagnósticos automáticos dos ECGs, mas, apesar disso, existem poucos estudos publicados acerca do desempenho desses equipamentos. O objetivo deste trabalho é avaliar o desempenho de um eletrocardiógrafo interpretativo para determinar sua adequabilidade para uso em um sistema computacional que utiliza informações da história clínica obtida pelo médico generalista e do laudo eletrocardiográfico emitido pelo equipamento avaliado, permitindo auxiliar no diagnóstico de síndromes coronarianas agudas, quando o paciente não é atendido por cardiologistas. Foi utilizado um eletrocardiógrafo interpretativo Nihon  Kohden Cardiofax  9620 que foi testado com um simulador de sinais eletrocardiográficos Metron  PS  420 e, ainda, teve seu desempenho comparado com um sistema de telemedicina disponível em uma região semi-rural brasileira. Os testes resultaram em 93,8 por cento de sensibilidade e 83,3 por cento de especificidade, que foram considerados satisfatórias em situações clínicas compatíveis com isquemia miocárdica aguda, validando a sua utilização em um sistema de inteligência artificial para auxílio ao diagnóstico em SCA.

The electrocardiogram  (ECG) is the recording of the heart’s  electrical activity from the surface of the body and has been worldwide used in routine medical practice since the last century. This is a first-rate tool for a rapid interpretation of cardiac rhythm and for assessment and immediate therapeutic management in patients with suspected acute coronary syndrome, which is a clinical entity that includes unstable  angina and acute myocardial infarction with and without ST-segment elevation. Currently, electrocardiographs from various manufacturers are capable of providing automatic diagnosis of ECGs, but there are few published studies about the performance of these equipments. The objective of this paper is to evaluate the performance of an interpretive electrocardiograph in order to determine their suitability for use in a computer system that uses the medical history information obtained by the general practitioner and the electrocardiographic report emitted by the equipment evaluated to aid the diagnosis of acute coronary syndromes, when the patient is not treated by cardiologists. We used an interpretive electrocardigraph Nihon  Kohden Cardiofax  9620. The electrocardiograph simulator Metron  PS  420 was the choice for the simulated tests, and also we compared the performance of the Cardiofax with a telemedicine system available in a semi-rural area in Brazil. The tests resulted in 93.8 percent sensitivity and 83.3 percent specificity that were considered satisfactory in clinical situations compatible with acute myocardial ischemia, validating their use in an artificial intelligence system for the diagnosis of ACS.

CAD e mamografia: por que usar esta ferramenta? / CAD and mammography: why use this tool?

A mamografia representa o melhor método de detecção precoce do câncer de mama, porém cerca de 10 por cento a 30 por cento das lesões mamárias são perdidas no rastreamento, devido a limitações próprias dos observadores humanos. A detecção auxiliada por computador (computer-aided detection - CAD) é uma tecnologia relativamente nova que tem sido implementada em alguns serviços de mamografia, com o intuito de prover uma dupla leitura. Estudos clínicos têm demonstrado que o CAD aumenta a sensibilidade de detecção do câncer da mama, por radiologistas, em até 21 por cento. Um sistema CAD é útil em situações em que exista alta variabilidade interobservador, falta de observadores treinados, ou na impossibilidade de se realizar a dupla leitura com dois ou mais radiologistas. O objetivo desta revisão está baseado na necessidade de atualizar a comunidade médica acerca desta ferramenta, como um método auxiliar, quantitativo, não operador-dependente, e que visa a melhorar a qualidade do diagnóstico do câncer de mama.

Mammography is the best method for early detection of breast cancer. Nevertheless, approximately 10 percent to 30 percent of breast lesions are missed at screening due to limitations of human observers. Computer-aided detection (CAD) is a relatively new technology that has been implemented in some mammography services to allow a double reading of mammograms. Clinical studies have demonstrated that CAD increases the sensitivity by up to 21 percent in the detection of breast cancer by radiologists. A CAD system is useful in situations where there is a high interobserver variability, lack of trained observers, or impossibility to perform the double reading with two or more radiologists. The objective of the present review is based on the need to get the medical community acquainted with this tool as an auxiliary, quantitative and non-operator-dependent method, to improve the diagnosis of breast cancer.

Identifying malingering symptoms of balance disorders by computerized dynamic posturography / 法医学杂志

OBJECTIVE@#To develop an objective criteria with computerized dynamic posturography (CDP) for identification of non-organic or malingering symptoms of balance disorders.@*METHODS@#One hundred and four normal subjects were instructed to feign balance disturbance after naturally performing on CDP. Paired t-test was used to determine if there was significant difference of CDP equilibrium scores between normal and malingering performance. The CDP records including raw curve of 50 subjects were critically evaluated by previously published seven criteria in indicating malingering performance. If the sensitivity of a criterion was greater than 90%, it would be accepted as our laboratory's identifying criterion. The CDP records of remaining 54 subjects were used to test the sensitivity and specificity of the accepted criteria.@*RESULTS@#There were statistically significant differences of CDP equilibrium scores between normal and malingering performance (P < 0.01). The mean equilibrium scores of malingering performance were lower than that of normal performance. The sensitivity and specificity of our criteria for identifying malingerers were 92.5% and 98.2%, respectively.@*CONCLUSION@#It is necessary to identify malingering performance before analyzing the CDP equilibrium scores. Our identifying criteria of malingerers seems to be quite useful and accurate.

A negative expiratory pressure test during wakefulness for evaluating the risk of obstructive sleep apnea in patients referred for sleep studies

OBJECTIVE: Obstructive sleep apnea is characterized by increased upper airway collapsibility during sleep. The present study investigated the use of the negative expiratory pressure test as a method to rule out obstructive sleep apnea. METHODS: Flow limitation was evaluated in 155 subjects. All subjects underwent a diurnal negative expiratory pressure test and a nocturnal sleep study. The severity of sleep apnea was determined based on the apneahypopnea index. Flow limitation was assessed by computing the exhaled volume at 0.2, 0.5, and 1.0 s (V0.2, V0.5, and V1.0, respectively) during the application of a negative expiratory pressure and expressed as a percentage of the previous exhaled volume. Receiver-operating characteristic curves were constructed to identify the optimal threshold volume at 0.2, 0.5, and 1.0 s for obstructive sleep apnea detection. RESULTS: Mean expiratory volumes at 0.2 and 0.5 s were statistically higher (p <0.01) in healthy subjects than in all obstructive sleep apneic groups. Increasing disease severity was associated with lower expiratory volumes. The V0.2 ( percent) predictive parameters for the detection of sleep apnea were sensitivity (81.1 percent), specificity (93.1 percent), PPV (98.1 percent), and NPV (52.9 percent). Sensitivity and NPV were 96.9 percent and 93.2 percent, respectively, for moderate-to-severe obstructive sleep apnea, and both were 100 percent for severe obstructive sleep apnea. CONCLUSION: Flow limitation measurement by V 0.2 ( percent) during wakefulness may be a very reliable method to identify obstructive sleep apnea when the test is positive and could reliably exclude moderate and severe obstructive sleep apnea when the test is negative. The negative expiratory pressure test appears to be a useful screening test for suspected obstructive sleep apnea.