Os autores descrevem o tratamento cirúrgico de um caso de pentalogia de Cantrell, rara anomalia c... more Os autores descrevem o tratamento cirúrgico de um caso de pentalogia de Cantrell, rara anomalia congênita, caracterizada por defeitos da parede abdominal, terço inferior do esterno, diafragma, pericárdio e coração.<br>The authors describe the surgical cure of a case of Pentalogy of Cantrell, a rare anomaly characterized by congenital lesions involving the abdominal wall, the inferior third of the sternum, the ventral diaphragm, the pericardium and the heart.
Introduction: Studies monitoring COVID-19 and its vaccines are warranted to expand knowledge abou... more Introduction: Studies monitoring COVID-19 and its vaccines are warranted to expand knowledge about the virus and its effects in humans. The objective of this study was to compare the reasons for referral and the fetal echocardiographic results during (PAND: Mar/20-Aug/21) and before (PREP: Set/19-Feb/20) the COVID-19 pandemic. Material and methods: Single outpatient centre, retrospective study. Results: A total of 10,778 fetal echocardiograms were performed; 10,732 corresponding to initial examinations performed in 10,551 pregnancies (10,376 singletons; 171 twins; 2 triplets; 2 quadruplets). Only first-time exams were reviewed. There were 5652 during PREP and 5080 during PAND. Maternal ages (X) varied between 14 and 46 years (X-PREP = 29.1and X-PAND = 29.2), and gestational weeks (Y) varied between 16 and 39 weeks (Y-PREP = 26.9 and Y-PAND = 27.6). The exams were not performed in women with known active COVID-19 infection. In PREP, more women were referred due to maternal or fetal risk factors. During PAND, more women were referred due to a suspected heart defect on ultrasound. During PAND we identified more fetuses with congenital heart disease and arrhythmias. A higher incidence of pericardial effusion, without structural heart disease, was observed during the months of June, July, and August 2021, compared to the remaining months (p < 0.001). Conclusions: The identification of more structural heart disease during PAND may reflect changes in referral patterns. The increase in isolated pericardial effusion coincided with the period of massive COVID-19 immunization. We hypothesize that this finding may reflect a transient inflammatory response that could signal to fetal immunization against SARS-CoV-2.
Proceedings of the 10th International Joint Conference on Biomedical Engineering Systems and Technologies, 2017
The mitral valve plays a vital role in our circulatory system. To study its functionality, it is ... more The mitral valve plays a vital role in our circulatory system. To study its functionality, it is important to measure clinically relevant parameters, such as its thickness, mobility and shape. Since manual segmentation is impractical, time consuming and requires expert knowledge, an automatic segmentation tool can have a significant clinical impact, providing objective measures to clinicians for understanding the morphology and behaviour of the mitral valve. In this work, a real time tracking method has been proposed for ultrasound videos obtained with the Parasternal Long Axis view. The algorithm is semi-automatic, assumes manual Anterior Mitral Leaflet segmentation in the first frame and then it uses mathematical morphology algorithms to obtain tracking results, further refined by localized active contours during the whole cardiac cycle. Finally, the medial axis is extracted for a quantitative analysis. Results show that the algorithm can segment 1137 frames extracted from 9 fully annotated sequences of the real clinical video data in only 0.89 sec/frame, with an average error of 5 pixels. Furthermore, the algorithms exhibited robust tracking performance in the most difficult situations, which are large frame-to-frame displacements.
Auscultation is currently both a powerful screening tool, providing a cheap and quick initial ass... more Auscultation is currently both a powerful screening tool, providing a cheap and quick initial assessment of a patient’s clinical condition, and a hard skill to master. Acquiring this skill is not only intrinsically difficult but our teaching methods are inadequate due to a variety of practical issues. In this chapter, we will discuss the difficulties of the art of auscultation, how we currently teach this skill and describe a novel simulation technology, IS4Learning, that can be used in three different teaching settings enabling us to train and evaluate students in the art of auscultation.
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2018
Rheumatic heart disease is responsible for the heart valve damage, caused by repeated episodes of... more Rheumatic heart disease is responsible for the heart valve damage, caused by repeated episodes of rheumatic fever. The disease commonly inflames and scars the mitral valve of the heart, resulting in thicker, less mobile leaflets, with associated decrease in cardiac efficiency. It is important to measure and quantity the early manifestations of this disease, including variations of the thickness, shape and mobility of the leaflets. These manifestations are visible in an echocardiographic screening process. The first step towards the defined objective is to segment the anterior mitral leaflet throughout the cardiac cycle, enabling the future automatic quantification of mentioned clinical parameters. In this work, a new algorithm for the segmentation of the whole region of the anterior mitral leaflet in the virtual M-mode space is proposed. The algorithm requires a single initialization point on the posterior wall of the aorta, in the first frame of the video. A junction point is then ...
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2018
Rheumatic heart disease is the serious consequence of repeated episodes of acute rheumatic fever.... more Rheumatic heart disease is the serious consequence of repeated episodes of acute rheumatic fever. It is the major cause of heart valve damage resulting in morbidity and mortality. Its early detection is considered vital to control the disease's progression. The key manifestations that are visible in the early stages of this disease are changes in the thickness, shape and mobility of the mitral valve leaflets. Echocardiography based screening is sensitive enough to identify these changes in early stages of the disease. In this work, an automatic approach is proposed to measure, quantify and analyze the thickness of the anterior mitral leaflet, in an echocardiographic video. The shape of the anterior mitral leaflet is simplified via morphological skeletonization and spline modelling to get the central line of the leaflet. To analyze the overall thickness from the tip to its base, the anterior mitral leaflet is divided into four quartiles. In ach quartile the thickness is measured ...
The 2013 International Joint Conference on Neural Networks (IJCNN), 2013
Machine learning techniques are an important tool for diagnosing a number of diseases, as has bee... more Machine learning techniques are an important tool for diagnosing a number of diseases, as has been shown by the recent literature. Hospitals and medical clinics have a huge amount of data about the treatment of their patients, however, rarely analysis of these data is performed in order to extract intrinsic information aimed at modeling a specific problem. This work presents an analysis of medical data aimed at determining whether children patients are cardiac or not. To this end, raw data was collected at a Brazilian local hospital to be preprocessed in order to build the classification models. Only non invasive information were used, such as height, weight, gender and birthday date to create another set of derived variables such as BMI (Body Mass Index) to support the classification phase. However, the collected data was shown to be very imbalanced. Aimed at treat this problem, many tecniques were employed and one new approach was proposed. The results shown that the proposed approach outperforms the other methods in three out of four evaluation metrics.
Journal of the American Society of Hypertension, 2014
Onset of hypertension during pregnancy is associated with long-term worse blood pressure control ... more Onset of hypertension during pregnancy is associated with long-term worse blood pressure control and adverse cardiac remodeling
Proceedings of the 25th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (IEEE Cat. No.03CH37439), 2003
The development of a collaborative environment to support a telecardiology service not only allow... more The development of a collaborative environment to support a telecardiology service not only allows for an interchange of medical information between remote centers, but also creates a new source of specialized consultation and distant education. The development of the collaborative environment with well-known tools to users in the Region, facilitates its set up, reduces the training required and optimises its
SummaryThis study aimed to assess the prevalence of “silent” valvar regurgitation in healthy Braz... more SummaryThis study aimed to assess the prevalence of “silent” valvar regurgitation in healthy Brazilian children; to determine whether variations in the gain settings of the machine interfered with its documentation; and to compare Doppler color flow mapping with the pulsed wave Doppler. Twenty-five healthy children were selected randomly. Echocardiographic equipment used was ALOKA 870. Fixed parameters were 3.5 MHz transducer, 400 Hz filter, reject of 7/14 and aperture of 30/80. Variable parameters were Doppler color flow mapping and pulsed wave Doppler gains. A protocol for evaluation of each cardiac valve was developed. Regurgitation was noted in 93% for the pulmonary valve, 74% for the tricuspid valve and 27% for the mitral valve. In the aortic valve, jets suggestive of mild valvar regurgitation were observed with the Doppler color flow mapping technique in two children but these findings were not corroborated by pulsed wave Doppler. Only in the aortic valve were findings from Do...
Archives of Disease in Childhood - Fetal and Neonatal Edition, 2011
To test whether customised (ct) growth criteria are more reliable than standard (st) ones to pred... more To test whether customised (ct) growth criteria are more reliable than standard (st) ones to predict intrauterine insult. 32 mothers and their singleton term neonates selected as small for gestational age (st-SGA=8) or appropriate for gestational age (st-AGA=24). Nitric oxide, high-sensitive C reactive protein (hs-CRP), uric acid, blood lipids and protein levels were analysed in maternal and cord blood. Applying customised criteria yielded 16 ct-AGA, 13 ct-SGA and 3 ct-LGA (large for gestational age) babies. Both st-SGA and ct-SGA babies had higher nitric oxide and hs-CRP levels. Their mothers had lower albumin fractions. st-SGA babies also had higher triglyceride and cholesterol levels. ct-LGA babies and mothers had higher uric acid levels, and the mothers had higher triglyceride levels. Customised growth criteria better identify babies submitted to unfavourable intrauterine environments. The authors suggest that combined with maternal biochemistry, these growth criteria can be used to screen for adverse fetal programming.
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, Jul 1, 2017
Echocardiography is an important tool to detect early evidence of mitral valve degradation associ... more Echocardiography is an important tool to detect early evidence of mitral valve degradation associated with rheumatic heart disease. The segmentation and tracking of the Anterior Mitral Leaflet helps to quantify the morphologic valve anomalies, such as the leaflet thickening, shape and the mobility changes. The tracking of this leaflet throughout the cardiac cycle is still an open challenge in the research community. The widely used active contours segmentation framework fails when faced with large leaflet displacement. In this work, we propose the integration of optical flow in an open-ended active contour framework to address this difficulty. This additional information promotes solutions with contours next to high leaflet displacements, resulting in superior performance. The algorithm was tested on 9 fully annotated real clinical videos, acquired from the parasternal long axis view. The algorithm is compared with our previous work. Results show a clear improvement in situations wh...
Cardiac auscultation is one of the most costeffective techniques used to detect and identify many... more Cardiac auscultation is one of the most costeffective techniques used to detect and identify many heart conditions. Computer-assisted decision systems based on auscultation can support physicians in their decisions. Unfortunately, the application of such systems in clinical trials is still minimal since most of them only aim to detect
Proceedings of the 10th International Joint Conference on Biomedical Engineering Systems and Technologies, 2017
Rheumatic Fever and Rheumatic Heart Disease remain a major burden among children in developing co... more Rheumatic Fever and Rheumatic Heart Disease remain a major burden among children in developing countries. Echocardiography with colour flow Doppler is key to early diagnosis. However, the technique requires time and experienced operators, which are scarce resources in the affected areas. Automatic segmentation of colour Doppler regurgitation jets could, potentially, reduce the cost of screening, and spread diagnostic accessibility for a larger number of patients. Ultrasound processing is very challenging due to speckle noise and similarity of representation of all kinds of tissue. Region-based active contours are suitable tools for the segmentation in cases of intensity heterogeneities, which makes them interesting algorithms for left atrium segmentation. HSV colour space describes colour in terms of hues and saturation, which may facilitate the translation of medical interpretation of the Doppler pseudo-colour into mathematical expression for colour segmentation. A total of 979 frames from 20 sequences were manually annotated and used to validate the proposed pipeline. Overall, the results for colour pattern segmentation are promising (sensitivity=0.91 false detection rate=0.10), but further developments are required for the atrium segmentation (sensitivity=0.80, false detection rate=0.28).
Biomedical Engineering Systems and Technologies, 2018
Rheumatic heart disease is the result of damage to the heart valves, more often the mitral valve.... more Rheumatic heart disease is the result of damage to the heart valves, more often the mitral valve. The heart valves leaflets get inflamed, scarred and stretched which interrupts the normal blood flow, resulting into serious health condition. Measuring and quantifying clinically relevant features, like thickness, mobility and shape can help to analyze the functionality of the valve, identify early cases of disease and reduce the disease burden. To obtain these features, the first step is to automatically delineate the relevant structures, such as the anterior mitral valve leaflet, throughout the echocardiographic video. In this work, we proposed a near real time method to track the anterior mitral leaflet in ultrasound videos using the parasternal long axis view. The method is semi-automatic, requiring a manual delineation of the anterior mitral leaflet in the first frame of the video. The method uses mathematical morphological techniques to obtain the rough boundaries of the leaflet and are further refined by the localized active contour framework. The mobility of the leaflet was also obtained, providing us the base to analyze the functionality of the valve (opening and closing). The algorithm was tested on 67 videos with 6432 frames. It outperformed with respect to the time consumption (0.4 s/frame), with the extended modified Hausdorff distance error of 3.7 pixels and the improved tracking performance (less failure).
Os autores descrevem o tratamento cirúrgico de um caso de pentalogia de Cantrell, rara anomalia c... more Os autores descrevem o tratamento cirúrgico de um caso de pentalogia de Cantrell, rara anomalia congênita, caracterizada por defeitos da parede abdominal, terço inferior do esterno, diafragma, pericárdio e coração.<br>The authors describe the surgical cure of a case of Pentalogy of Cantrell, a rare anomaly characterized by congenital lesions involving the abdominal wall, the inferior third of the sternum, the ventral diaphragm, the pericardium and the heart.
Introduction: Studies monitoring COVID-19 and its vaccines are warranted to expand knowledge abou... more Introduction: Studies monitoring COVID-19 and its vaccines are warranted to expand knowledge about the virus and its effects in humans. The objective of this study was to compare the reasons for referral and the fetal echocardiographic results during (PAND: Mar/20-Aug/21) and before (PREP: Set/19-Feb/20) the COVID-19 pandemic. Material and methods: Single outpatient centre, retrospective study. Results: A total of 10,778 fetal echocardiograms were performed; 10,732 corresponding to initial examinations performed in 10,551 pregnancies (10,376 singletons; 171 twins; 2 triplets; 2 quadruplets). Only first-time exams were reviewed. There were 5652 during PREP and 5080 during PAND. Maternal ages (X) varied between 14 and 46 years (X-PREP = 29.1and X-PAND = 29.2), and gestational weeks (Y) varied between 16 and 39 weeks (Y-PREP = 26.9 and Y-PAND = 27.6). The exams were not performed in women with known active COVID-19 infection. In PREP, more women were referred due to maternal or fetal risk factors. During PAND, more women were referred due to a suspected heart defect on ultrasound. During PAND we identified more fetuses with congenital heart disease and arrhythmias. A higher incidence of pericardial effusion, without structural heart disease, was observed during the months of June, July, and August 2021, compared to the remaining months (p < 0.001). Conclusions: The identification of more structural heart disease during PAND may reflect changes in referral patterns. The increase in isolated pericardial effusion coincided with the period of massive COVID-19 immunization. We hypothesize that this finding may reflect a transient inflammatory response that could signal to fetal immunization against SARS-CoV-2.
Proceedings of the 10th International Joint Conference on Biomedical Engineering Systems and Technologies, 2017
The mitral valve plays a vital role in our circulatory system. To study its functionality, it is ... more The mitral valve plays a vital role in our circulatory system. To study its functionality, it is important to measure clinically relevant parameters, such as its thickness, mobility and shape. Since manual segmentation is impractical, time consuming and requires expert knowledge, an automatic segmentation tool can have a significant clinical impact, providing objective measures to clinicians for understanding the morphology and behaviour of the mitral valve. In this work, a real time tracking method has been proposed for ultrasound videos obtained with the Parasternal Long Axis view. The algorithm is semi-automatic, assumes manual Anterior Mitral Leaflet segmentation in the first frame and then it uses mathematical morphology algorithms to obtain tracking results, further refined by localized active contours during the whole cardiac cycle. Finally, the medial axis is extracted for a quantitative analysis. Results show that the algorithm can segment 1137 frames extracted from 9 fully annotated sequences of the real clinical video data in only 0.89 sec/frame, with an average error of 5 pixels. Furthermore, the algorithms exhibited robust tracking performance in the most difficult situations, which are large frame-to-frame displacements.
Auscultation is currently both a powerful screening tool, providing a cheap and quick initial ass... more Auscultation is currently both a powerful screening tool, providing a cheap and quick initial assessment of a patient’s clinical condition, and a hard skill to master. Acquiring this skill is not only intrinsically difficult but our teaching methods are inadequate due to a variety of practical issues. In this chapter, we will discuss the difficulties of the art of auscultation, how we currently teach this skill and describe a novel simulation technology, IS4Learning, that can be used in three different teaching settings enabling us to train and evaluate students in the art of auscultation.
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2018
Rheumatic heart disease is responsible for the heart valve damage, caused by repeated episodes of... more Rheumatic heart disease is responsible for the heart valve damage, caused by repeated episodes of rheumatic fever. The disease commonly inflames and scars the mitral valve of the heart, resulting in thicker, less mobile leaflets, with associated decrease in cardiac efficiency. It is important to measure and quantity the early manifestations of this disease, including variations of the thickness, shape and mobility of the leaflets. These manifestations are visible in an echocardiographic screening process. The first step towards the defined objective is to segment the anterior mitral leaflet throughout the cardiac cycle, enabling the future automatic quantification of mentioned clinical parameters. In this work, a new algorithm for the segmentation of the whole region of the anterior mitral leaflet in the virtual M-mode space is proposed. The algorithm requires a single initialization point on the posterior wall of the aorta, in the first frame of the video. A junction point is then ...
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2018
Rheumatic heart disease is the serious consequence of repeated episodes of acute rheumatic fever.... more Rheumatic heart disease is the serious consequence of repeated episodes of acute rheumatic fever. It is the major cause of heart valve damage resulting in morbidity and mortality. Its early detection is considered vital to control the disease's progression. The key manifestations that are visible in the early stages of this disease are changes in the thickness, shape and mobility of the mitral valve leaflets. Echocardiography based screening is sensitive enough to identify these changes in early stages of the disease. In this work, an automatic approach is proposed to measure, quantify and analyze the thickness of the anterior mitral leaflet, in an echocardiographic video. The shape of the anterior mitral leaflet is simplified via morphological skeletonization and spline modelling to get the central line of the leaflet. To analyze the overall thickness from the tip to its base, the anterior mitral leaflet is divided into four quartiles. In ach quartile the thickness is measured ...
The 2013 International Joint Conference on Neural Networks (IJCNN), 2013
Machine learning techniques are an important tool for diagnosing a number of diseases, as has bee... more Machine learning techniques are an important tool for diagnosing a number of diseases, as has been shown by the recent literature. Hospitals and medical clinics have a huge amount of data about the treatment of their patients, however, rarely analysis of these data is performed in order to extract intrinsic information aimed at modeling a specific problem. This work presents an analysis of medical data aimed at determining whether children patients are cardiac or not. To this end, raw data was collected at a Brazilian local hospital to be preprocessed in order to build the classification models. Only non invasive information were used, such as height, weight, gender and birthday date to create another set of derived variables such as BMI (Body Mass Index) to support the classification phase. However, the collected data was shown to be very imbalanced. Aimed at treat this problem, many tecniques were employed and one new approach was proposed. The results shown that the proposed approach outperforms the other methods in three out of four evaluation metrics.
Journal of the American Society of Hypertension, 2014
Onset of hypertension during pregnancy is associated with long-term worse blood pressure control ... more Onset of hypertension during pregnancy is associated with long-term worse blood pressure control and adverse cardiac remodeling
Proceedings of the 25th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (IEEE Cat. No.03CH37439), 2003
The development of a collaborative environment to support a telecardiology service not only allow... more The development of a collaborative environment to support a telecardiology service not only allows for an interchange of medical information between remote centers, but also creates a new source of specialized consultation and distant education. The development of the collaborative environment with well-known tools to users in the Region, facilitates its set up, reduces the training required and optimises its
SummaryThis study aimed to assess the prevalence of “silent” valvar regurgitation in healthy Braz... more SummaryThis study aimed to assess the prevalence of “silent” valvar regurgitation in healthy Brazilian children; to determine whether variations in the gain settings of the machine interfered with its documentation; and to compare Doppler color flow mapping with the pulsed wave Doppler. Twenty-five healthy children were selected randomly. Echocardiographic equipment used was ALOKA 870. Fixed parameters were 3.5 MHz transducer, 400 Hz filter, reject of 7/14 and aperture of 30/80. Variable parameters were Doppler color flow mapping and pulsed wave Doppler gains. A protocol for evaluation of each cardiac valve was developed. Regurgitation was noted in 93% for the pulmonary valve, 74% for the tricuspid valve and 27% for the mitral valve. In the aortic valve, jets suggestive of mild valvar regurgitation were observed with the Doppler color flow mapping technique in two children but these findings were not corroborated by pulsed wave Doppler. Only in the aortic valve were findings from Do...
Archives of Disease in Childhood - Fetal and Neonatal Edition, 2011
To test whether customised (ct) growth criteria are more reliable than standard (st) ones to pred... more To test whether customised (ct) growth criteria are more reliable than standard (st) ones to predict intrauterine insult. 32 mothers and their singleton term neonates selected as small for gestational age (st-SGA=8) or appropriate for gestational age (st-AGA=24). Nitric oxide, high-sensitive C reactive protein (hs-CRP), uric acid, blood lipids and protein levels were analysed in maternal and cord blood. Applying customised criteria yielded 16 ct-AGA, 13 ct-SGA and 3 ct-LGA (large for gestational age) babies. Both st-SGA and ct-SGA babies had higher nitric oxide and hs-CRP levels. Their mothers had lower albumin fractions. st-SGA babies also had higher triglyceride and cholesterol levels. ct-LGA babies and mothers had higher uric acid levels, and the mothers had higher triglyceride levels. Customised growth criteria better identify babies submitted to unfavourable intrauterine environments. The authors suggest that combined with maternal biochemistry, these growth criteria can be used to screen for adverse fetal programming.
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, Jul 1, 2017
Echocardiography is an important tool to detect early evidence of mitral valve degradation associ... more Echocardiography is an important tool to detect early evidence of mitral valve degradation associated with rheumatic heart disease. The segmentation and tracking of the Anterior Mitral Leaflet helps to quantify the morphologic valve anomalies, such as the leaflet thickening, shape and the mobility changes. The tracking of this leaflet throughout the cardiac cycle is still an open challenge in the research community. The widely used active contours segmentation framework fails when faced with large leaflet displacement. In this work, we propose the integration of optical flow in an open-ended active contour framework to address this difficulty. This additional information promotes solutions with contours next to high leaflet displacements, resulting in superior performance. The algorithm was tested on 9 fully annotated real clinical videos, acquired from the parasternal long axis view. The algorithm is compared with our previous work. Results show a clear improvement in situations wh...
Cardiac auscultation is one of the most costeffective techniques used to detect and identify many... more Cardiac auscultation is one of the most costeffective techniques used to detect and identify many heart conditions. Computer-assisted decision systems based on auscultation can support physicians in their decisions. Unfortunately, the application of such systems in clinical trials is still minimal since most of them only aim to detect
Proceedings of the 10th International Joint Conference on Biomedical Engineering Systems and Technologies, 2017
Rheumatic Fever and Rheumatic Heart Disease remain a major burden among children in developing co... more Rheumatic Fever and Rheumatic Heart Disease remain a major burden among children in developing countries. Echocardiography with colour flow Doppler is key to early diagnosis. However, the technique requires time and experienced operators, which are scarce resources in the affected areas. Automatic segmentation of colour Doppler regurgitation jets could, potentially, reduce the cost of screening, and spread diagnostic accessibility for a larger number of patients. Ultrasound processing is very challenging due to speckle noise and similarity of representation of all kinds of tissue. Region-based active contours are suitable tools for the segmentation in cases of intensity heterogeneities, which makes them interesting algorithms for left atrium segmentation. HSV colour space describes colour in terms of hues and saturation, which may facilitate the translation of medical interpretation of the Doppler pseudo-colour into mathematical expression for colour segmentation. A total of 979 frames from 20 sequences were manually annotated and used to validate the proposed pipeline. Overall, the results for colour pattern segmentation are promising (sensitivity=0.91 false detection rate=0.10), but further developments are required for the atrium segmentation (sensitivity=0.80, false detection rate=0.28).
Biomedical Engineering Systems and Technologies, 2018
Rheumatic heart disease is the result of damage to the heart valves, more often the mitral valve.... more Rheumatic heart disease is the result of damage to the heart valves, more often the mitral valve. The heart valves leaflets get inflamed, scarred and stretched which interrupts the normal blood flow, resulting into serious health condition. Measuring and quantifying clinically relevant features, like thickness, mobility and shape can help to analyze the functionality of the valve, identify early cases of disease and reduce the disease burden. To obtain these features, the first step is to automatically delineate the relevant structures, such as the anterior mitral valve leaflet, throughout the echocardiographic video. In this work, we proposed a near real time method to track the anterior mitral leaflet in ultrasound videos using the parasternal long axis view. The method is semi-automatic, requiring a manual delineation of the anterior mitral leaflet in the first frame of the video. The method uses mathematical morphological techniques to obtain the rough boundaries of the leaflet and are further refined by the localized active contour framework. The mobility of the leaflet was also obtained, providing us the base to analyze the functionality of the valve (opening and closing). The algorithm was tested on 67 videos with 6432 frames. It outperformed with respect to the time consumption (0.4 s/frame), with the extended modified Hausdorff distance error of 3.7 pixels and the improved tracking performance (less failure).
Uploads
Papers by Sandra Mattos