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1.
J Stroke Cerebrovasc Dis ; 30(8): 105905, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34107418

RESUMEN

PURPOSE: In the past years the significance of white matter hyperintensities (WMH) has gained raising attention because it is considered a marker of severity of different pathologies. Another condition that in the last years has been assessed in the neuroradiology field is cerebral microbleeds (CMB). The purpose of this work was to evaluate the association between the volume of WMH and the presence and characteristics of CMB. MATERIAL AND METHODS: Sixty-five consecutive (males 45; median age 70) subjects were retrospectively analyzed with a 1.5 Tesla scanner. WMH volume was quantified with a semi-automated procedure considering the FLAIR MR sequences whereas the CMB were studied with the SWI technique and CMBs were classified as absent (grade 1), mild (grade 2; total number of CMBs: 1-2), moderate (grade 3; total number of CMBs: 3-10), and severe (grade 4; total number of CMBs: >10). Moreover, overall number of CMBs and the maximum diameter were registered. RESULTS: Prevalence of CMBs was 30.76% whereas WMH 81.5%. Mann-Whitney test showed a statistically significant difference in WMH volume between subjects with and without CMBs (p < 0.001). Pearson analysis showed significant correlation between CMB grade, number and maximum diameter and WMH. The better ROC area under the curve (Az) was obtained by the hemisphere volume with a 0.828 (95% CI from 0.752 to 0,888; SD = 0.0427; p value = 0.001). The only parameters that showed a statistically significant association in the logistic regression analysis were Hemisphere volume of WMH (p = 0.001) and Cholesterol LDL (p = 0.0292). CONCLUSION: In conclusion, the results of this study suggest the presence of a significant correlation between CMBs and volume of WMH. No differences were found between the different vascular territories.


Asunto(s)
Hemorragia Cerebral/diagnóstico por imagen , Leucoencefalopatías/diagnóstico por imagen , Imagen por Resonancia Magnética , Sustancia Blanca/diagnóstico por imagen , Anciano , Anciano de 80 o más Años , Hemorragia Cerebral/epidemiología , Femenino , Humanos , Hipertensión/epidemiología , Leucoencefalopatías/epidemiología , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Prevalencia , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo
2.
Rev Cardiovasc Med ; 21(4): 541-560, 2020 12 30.
Artículo en Inglés | MEDLINE | ID: mdl-33387999

RESUMEN

Artificial Intelligence (AI), in general, refers to the machines (or computers) that mimic "cognitive" functions that we associate with our mind, such as "learning" and "solving problem". New biomarkers derived from medical imaging are being discovered and are then fused with non-imaging biomarkers (such as office, laboratory, physiological, genetic, epidemiological, and clinical-based biomarkers) in a big data framework, to develop AI systems. These systems can support risk prediction and monitoring. This perspective narrative shows the powerful methods of AI for tracking cardiovascular risks. We conclude that AI could potentially become an integral part of the COVID-19 disease management system. Countries, large and small, should join hands with the WHO in building biobanks for scientists around the world to build AI-based platforms for tracking the cardiovascular risk assessment during COVID-19 times and long-term follow-up of the survivors.


Asunto(s)
Inteligencia Artificial , COVID-19/epidemiología , Enfermedades Cardiovasculares/epidemiología , Atención a la Salud/métodos , Pandemias , Medición de Riesgo , SARS-CoV-2 , Enfermedades Cardiovasculares/terapia , Comorbilidad , Humanos , Factores de Riesgo
3.
Neuroradiology ; 62(3): 377-387, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31796984

RESUMEN

PURPOSE: It is under debate how white matter hyperintensities (WMH) affects the brain connectivity. The objective of this research study is to validate the hypothesis, if and how the WMH influences brain connectivity in a population with carotid artery stenosis (CAS), which are eligible for carotid endarterectomy (CEA). We used resting state functional connectivity (rs-fc) magnetic resonance (MR) to validate our hypothesis, focusing on the effects of the total number of WMH (TNWMH) and of the WMH Burden (WMHB). METHODS: Twenty-three patients (sixteen males and seven females, mean age 74.34 years) with mono or bilateral carotid stenosis eligible for carotid endarterectomy (CEA), underwent an MR examination on a 1.5-T scanner. The protocol included a morphologic T1-3D isotropic, an EPI functional sequence for rs-fc MR analysis, and a 3D isotropic FLAIR sequence. For each patient, the TNWMH and the WMHB were obtained using two online tools-volBrain and lesionBrain. The rs-fc region-of-interest to region-of-interest (ROI-to-ROI) analysis was performed with the CONN toolbox v18a: two different multiple regression analyses including both WMHB and TNWMH as second-level covariates evaluated the individual effects of WMHB (Analysis A) and TNWMH (Analysis B), adopting a p value corrected for false discovery rate (p-FDR) < 0.05 to identify statistically significant values. RESULTS: Both analyses A and B identified several statistically significant positive and negative correlations associated with WMHB and TNWMH. CONCLUSION: WMH influence functional connectivity in patients with carotid artery stenosis eligible for CEA; further, WMHB and TNWMH influence differently functional connectivity.


Asunto(s)
Estenosis Carotídea/complicaciones , Conectoma , Imagen por Resonancia Magnética/métodos , Sustancia Blanca/diagnóstico por imagen , Anciano , Femenino , Humanos , Imagenología Tridimensional , Masculino
4.
Curr Atheroscler Rep ; 21(2): 7, 2019 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-30684090

RESUMEN

PURPOSE OF THE REVIEW: Rheumatoid arthritis (RA) is a chronic, autoimmune disease which may result in a higher risk of cardiovascular (CV) events and stroke. Tissue characterization and risk stratification of patients with rheumatoid arthritis are a challenging problem. Risk stratification of RA patients using traditional risk factor-based calculators either underestimates or overestimates the CV risk. Advancements in medical imaging have facilitated early and accurate CV risk stratification compared to conventional cardiovascular risk calculators. RECENT FINDING: In recent years, a link between carotid atherosclerosis and rheumatoid arthritis has been widely discussed by multiple studies. Imaging the carotid artery using 2-D ultrasound is a noninvasive, economic, and efficient imaging approach that provides an atherosclerotic plaque tissue-specific image. Such images can help to morphologically characterize the plaque type and accurately measure vital phenotypes such as media wall thickness and wall variability. Intelligence-based paradigms such as machine learning- and deep learning-based techniques not only automate the risk characterization process but also provide an accurate CV risk stratification for better management of RA patients. This review provides a brief understanding of the pathogenesis of RA and its association with carotid atherosclerosis imaged using the B-mode ultrasound technique. Lacunas in traditional risk scores and the role of machine learning-based tissue characterization algorithms are discussed and could facilitate cardiovascular risk assessment in RA patients. The key takeaway points from this review are the following: (i) inflammation is a common link between RA and atherosclerotic plaque buildup, (ii) carotid ultrasound is a better choice to characterize the atherosclerotic plaque tissues in RA patients, and (iii) intelligence-based paradigms are useful for accurate tissue characterization and risk stratification of RA patients.


Asunto(s)
Artritis Reumatoide/complicaciones , Aterosclerosis/diagnóstico por imagen , Aterosclerosis/etiología , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/etiología , Aprendizaje Profundo , Artritis Reumatoide/patología , Arterias Carótidas/patología , Humanos , Inflamación/complicaciones , Inflamación/metabolismo , Placa Aterosclerótica/diagnóstico por imagen , Placa Aterosclerótica/etiología , Placa Aterosclerótica/metabolismo , Medición de Riesgo , Factores de Riesgo , Tomografía de Coherencia Óptica , Ultrasonografía
5.
Curr Atheroscler Rep ; 21(7): 25, 2019 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-31041615

RESUMEN

PURPOSE OF REVIEW: Cardiovascular disease (CVD) and stroke risk assessment have been largely based on the success of traditional statistically derived risk calculators such as Pooled Cohort Risk Score or Framingham Risk Score. However, over the last decade, automated computational paradigms such as machine learning (ML) and deep learning (DL) techniques have penetrated into a variety of medical domains including CVD/stroke risk assessment. This review is mainly focused on the changing trends in CVD/stroke risk assessment and its stratification from statistical-based models to ML-based paradigms using non-invasive carotid ultrasonography. RECENT FINDINGS: In this review, ML-based strategies are categorized into two types: non-image (or conventional ML-based) and image-based (or integrated ML-based). The success of conventional (non-image-based) ML-based algorithms lies in the different data-driven patterns or features which are used to train the ML systems. Typically these features are the patients' demographics, serum biomarkers, and multiple clinical parameters. The integrated (image-based) ML-based algorithms integrate the features derived from the ultrasound scans of the arterial walls (such as morphological measurements) with conventional risk factors in ML frameworks. Even though the review covers ML-based system designs for carotid and coronary ultrasonography, the main focus of the review is on CVD/stroke risk scores based on carotid ultrasound. There are two key conclusions from this review: (i) fusion of image-based features with conventional cardiovascular risk factors can lead to more accurate CVD/stroke risk stratification; (ii) the ability to handle multiple sources of information in big data framework using artificial intelligence-based paradigms (such as ML and DL) is likely to be the future in preventive CVD/stroke risk assessment.


Asunto(s)
Infarto del Miocardio/diagnóstico por imagen , Infarto del Miocardio/prevención & control , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/prevención & control , Ultrasonografía/métodos , Algoritmos , Enfermedades de las Arterias Carótidas/complicaciones , Aprendizaje Profundo , Humanos , Infarto del Miocardio/etiología , Placa Aterosclerótica/complicaciones , Medición de Riesgo/métodos , Medición de Riesgo/tendencias , Factores de Riesgo , Accidente Cerebrovascular/etiología
6.
Echocardiography ; 36(2): 345-361, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30623485

RESUMEN

MOTIVATION: This study presents a novel nonlinear model which can predict 10-year carotid ultrasound image-based phenotypes by fusing nine traditional cardiovascular risk factors (ethnicity, gender, age, artery type, body mass index, hemoglobin A1c, hypertension, low-density lipoprotein, and smoking) with five types of carotid automated image phenotypes (three types of carotid intima-media thickness (IMT), wall variability, and total plaque area). METHODOLOGY: Two-step process was adapted: First, five baseline carotid image-based phenotypes were automatically measured using AtheroEdge™ (AtheroPoint™ , CA, USA) system by two operators (novice and experienced) and an expert. Second, based on the annual progression rates of cIMT due to nine traditional cardiovascular risk factors, a novel nonlinear model was adapted for 10-year predictions of carotid phenotypes. RESULTS: Institute review board (IRB) approved 204 Japanese patients' left/right common carotid artery (407 ultrasound scans) was collected with a mean age of 69 ± 11 years. Age and hemoglobin were reported to have a high influence on the 10-year carotid phenotypes. Mean correlation coefficient (CC) between 10-year carotid image-based phenotype and age was improved by 39.35% in males and 25.38% in females. The area under the curves for the 10-year measurements of five phenotypes IMTave10yr , IMTmax10yr , IMTmin10yr , IMTV10yr , and TPA10yr were 0.96, 0.94, 0.90, 1.0, and 1.0. Inter-operator variability between two operators showed significant CC (P < 0.0001). CONCLUSIONS: A nonlinear model was developed and validated by fusing nine conventional CV risk factors with current carotid image-based phenotypes for predicting the 10-year carotid ultrasound image-based phenotypes which may be used risk assessment.


Asunto(s)
Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/epidemiología , Diabetes Mellitus , Anciano , Arterias Carótidas/diagnóstico por imagen , Arterias Carótidas/patología , Enfermedades de las Arterias Carótidas/patología , Estudios de Cohortes , Femenino , Humanos , Japón/epidemiología , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Medición de Riesgo , Ultrasonografía/métodos
7.
J Med Syst ; 42(5): 92, 2018 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-29637403

RESUMEN

Diabetes mellitus is a group of metabolic diseases in which blood sugar levels are too high. About 8.8% of the world was diabetic in 2017. It is projected that this will reach nearly 10% by 2045. The major challenge is that when machine learning-based classifiers are applied to such data sets for risk stratification, leads to lower performance. Thus, our objective is to develop an optimized and robust machine learning (ML) system under the assumption that missing values or outliers if replaced by a median configuration will yield higher risk stratification accuracy. This ML-based risk stratification is designed, optimized and evaluated, where: (i) the features are extracted and optimized from the six feature selection techniques (random forest, logistic regression, mutual information, principal component analysis, analysis of variance, and Fisher discriminant ratio) and combined with ten different types of classifiers (linear discriminant analysis, quadratic discriminant analysis, naïve Bayes, Gaussian process classification, support vector machine, artificial neural network, Adaboost, logistic regression, decision tree, and random forest) under the hypothesis that both missing values and outliers when replaced by computed medians will improve the risk stratification accuracy. Pima Indian diabetic dataset (768 patients: 268 diabetic and 500 controls) was used. Our results demonstrate that on replacing the missing values and outliers by group median and median values, respectively and further using the combination of random forest feature selection and random forest classification technique yields an accuracy, sensitivity, specificity, positive predictive value, negative predictive value and area under the curve as: 92.26%, 95.96%, 79.72%, 91.14%, 91.20%, and 0.93, respectively. This is an improvement of 10% over previously developed techniques published in literature. The system was validated for its stability and reliability. RF-based model showed the best performance when outliers are replaced by median values.


Asunto(s)
Diabetes Mellitus/clasificación , Diabetes Mellitus/epidemiología , Aprendizaje Automático , Adulto , Distribución por Edad , Inteligencia Artificial , Teorema de Bayes , Glucemia , Presión Sanguínea , Pesos y Medidas Corporales , Interpretación Estadística de Datos , Técnicas de Apoyo para la Decisión , Femenino , Humanos , Indígenas Norteamericanos , Masculino , Persona de Mediana Edad , Redes Neurales de la Computación , Reproducibilidad de los Resultados , Distribución por Sexo , Estados Unidos
8.
J Med Syst ; 41(6): 98, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28501967

RESUMEN

Severe atherosclerosis disease in carotid arteries causes stenosis which in turn leads to stroke. Machine learning systems have been previously developed for plaque wall risk assessment using morphology-based characterization. The fundamental assumption in such systems is the extraction of the grayscale features of the plaque region. Even though these systems have the ability to perform risk stratification, they lack the ability to achieve higher performance due their inability to select and retain dominant features. This paper introduces a polling-based principal component analysis (PCA) strategy embedded in the machine learning framework to select and retain dominant features, resulting in superior performance. This leads to more stability and reliability. The automated system uses offline image data along with the ground truth labels to generate the parameters, which are then used to transform the online grayscale features to predict the risk of stroke. A set of sixteen grayscale plaque features is computed. Utilizing the cross-validation protocol (K = 10), and the PCA cutoff of 0.995, the machine learning system is able to achieve an accuracy of 98.55 and 98.83%corresponding to the carotidfar wall and near wall plaques, respectively. The corresponding reliability of the system was 94.56 and 95.63%, respectively. The automated system was validated against the manual risk assessment system and the precision of merit for same cross-validation settings and PCA cutoffs are 98.28 and 93.92%for the far and the near wall, respectively.PCA-embedded morphology-based plaque characterization shows a powerful strategy for risk assessment and can be adapted in clinical settings.


Asunto(s)
Placa Aterosclerótica , Arterias Carótidas , Estenosis Carotídea , Humanos , Análisis de Componente Principal , Reproducibilidad de los Resultados , Accidente Cerebrovascular , Ultrasonografía
9.
J Med Syst ; 41(10): 152, 2017 08 23.
Artículo en Inglés | MEDLINE | ID: mdl-28836045

RESUMEN

Fatty Liver Disease (FLD) is caused by the deposition of fat in liver cells and leads to deadly diseases such as liver cancer. Several FLD detection and characterization systems using machine learning (ML) based on Support Vector Machines (SVM) have been applied. These ML systems utilize large number of ultrasonic grayscale features, pooling strategy for selecting the best features and several combinations of training/testing. As result, they are computationally intensive, slow and do not guarantee high performance due to mismatch between grayscale features and classifier type. This study proposes a reliable and fast Extreme Learning Machine (ELM)-based tissue characterization system (a class of Symtosis) for risk stratification of ultrasound liver images. ELM is used to train single layer feed forward neural network (SLFFNN). The input-to-hidden layer weights are randomly generated reducing computational cost. The only weights to be trained are hidden-to-output layer which is done in a single pass (without any iteration) making ELM faster than conventional ML methods. Adapting four types of K-fold cross-validation (K = 2, 3, 5 and 10) protocols on three kinds of data sizes: S0-original, S4-four splits, S8-sixty four splits (a total of 12 cases) and 46 types of grayscale features, we stratify the FLD US images using ELM and benchmark against SVM. Using the US liver database of 63 patients (27 normal/36 abnormal), our results demonstrate superior performance of ELM compared to SVM, for all cross-validation protocols (K2, K3, K5 and K10) and all types of US data sets (S0, S4, and S8) in terms of sensitivity, specificity, accuracy and area under the curve (AUC). Using the K10 cross-validation protocol on S8 data set, ELM showed an accuracy of 96.75% compared to 89.01% for SVM, and correspondingly, the AUC: 0.97 and 0.91, respectively. Further experiments also showed the mean reliability of 99% for ELM classifier, along with the mean speed improvement of 40% using ELM against SVM. We validated the symtosis system using two class biometric facial public data demonstrating an accuracy of 100%.


Asunto(s)
Hepatopatías , Algoritmos , Humanos , Redes Neurales de la Computación , Reproducibilidad de los Resultados , Máquina de Vectores de Soporte
10.
J Med Syst ; 42(1): 18, 2017 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-29218604

RESUMEN

The original version of this article unfortunately contained a mistake. The family name of Rui Tato Marinho was incorrectly spelled as Marinhoe.

11.
Curr Atheroscler Rep ; 18(12): 83, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27830569

RESUMEN

Functional and structural changes in the common carotid artery are biomarkers for cardiovascular risk. Current methods for measuring functional changes include pulse wave velocity, compliance, distensibility, strain, stress, stiffness, and elasticity derived from arterial waveforms. The review is focused on the ultrasound-based carotid artery elasticity and stiffness measurements covering the physics of elasticity and linking it to biological evolution of arterial stiffness. The paper also presents evolution of plaque with a focus on the pathophysiologic cascade leading to arterial hardening. Using the concept of strain, and image-based elasticity, the paper then reviews the lumen diameter and carotid intima-media thickness measurements in combined temporal and spatial domains. Finally, the review presents the factors which influence the understanding of atherosclerotic disease formation and cardiovascular risk including arterial stiffness, tissue morphological characteristics, and image-based elasticity measurement.


Asunto(s)
Arteriosclerosis/diagnóstico por imagen , Rigidez Vascular , Arteriosclerosis/fisiopatología , Enfermedades Cardiovasculares , Elasticidad , Humanos , Factores de Riesgo , Ultrasonografía
12.
J Med Syst ; 40(7): 182, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27299355

RESUMEN

The degree of stenosis in the carotid artery can be predicted using automated carotid lumen diameter (LD) measured from B-mode ultrasound images. Systolic velocity-based methods for measurement of LD are subjective. With the advancement of high resolution imaging, image-based methods have started to emerge. However, they require robust image analysis for accurate LD measurement. This paper presents two different algorithms for automated segmentation of the lumen borders in carotid ultrasound images. Both algorithms are modeled as a two stage process. Stage one consists of a global-based model using scale-space framework for the extraction of the region of interest. This stage is common to both algorithms. Stage two is modeled using a local-based strategy that extracts the lumen interfaces. At this stage, the algorithm-1 is modeled as a region-based strategy using a classification framework, whereas the algorithm-2 is modeled as a boundary-based approach that uses the level set framework. Two sets of databases (DB), Japan DB (JDB) (202 patients, 404 images) and Hong Kong DB (HKDB) (50 patients, 300 images) were used in this study. Two trained neuroradiologists performed manual LD tracings. The mean automated LD measured was 6.35 ± 0.95 mm for JDB and 6.20 ± 1.35 mm for HKDB. The precision-of-merit was: 97.4 % and 98.0 % w.r.t to two manual tracings for JDB and 99.7 % and 97.9 % w.r.t to two manual tracings for HKDB. Statistical tests such as ANOVA, Chi-Squared, T-test, and Mann-Whitney test were conducted to show the stability and reliability of the automated techniques.


Asunto(s)
Algoritmos , Arterias Carótidas/diagnóstico por imagen , Estenosis Carotídea/diagnóstico , Interpretación de Imagen Asistida por Computador/métodos , Ultrasonografía/métodos , Anciano , Estenosis Carotídea/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados
13.
Comput Biol Med ; 123: 103847, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32768040

RESUMEN

MOTIVATION: The early screening of cardiovascular diseases (CVD) can lead to effective treatment. Thus, accurate and reliable atherosclerotic carotid wall detection and plaque measurements are crucial. Current measurement methods are time-consuming and do not utilize the power of knowledge-based paradigms such as artificial intelligence (AI). We present an AI-based methodology for the joint automated detection and measurement of wall thickness and carotid plaque (CP) in the form of carotid intima-media thickness (cIMT) and total plaque area (TPA), a class of AtheroEdge™ system (AtheroPoint™, CA, USA). METHOD: The novel system consists of two stages, and each stage comprises an independent deep learning (DL) model. In Stage I, the first DL model segregates the common carotid artery (CCA) patches from ultrasound (US) images into the rectangular wall and non-wall patches. The characterized wall patches are integrated to form the region of interest (ROI), which is then fed into Stage II. In Stage II, the second DL model segments the far wall region. Lumen-intima (LI) and media-adventitial (MA) boundaries are then extracted from the wall region, which is then used for cIMT and PA measurement. RESULTS: Using the database of 250 carotid scans, the cIMT error using the AI model is 0.0935±0.0637 mm, which is lower than those of all previous methods. The PA error is found to be 2.7939±2.3702 mm2. The system's correlation coefficient (CC) between AI and ground truth (GT) values for cIMT is 0.99 (p < 0.0001), which is higher compared with the CC of 0.96 (p < 0.0001) shown by the earlier DL method. The CC for PA between AI and GT values is 0.89 (p < 0.0001). CONCLUSION: A novel AI-based strategy was applied to carotid US images for the joint detection of carotid wall thickness (cWT) and plaque area (PA), followed by cIMT and PA measurement. This AI-based strategy shows improved performance using the patch technique compared with previous methods using full carotid scans.


Asunto(s)
Enfermedades de las Arterias Carótidas , Placa Aterosclerótica , Accidente Cerebrovascular , Inteligencia Artificial , Arterias Carótidas/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Grosor Intima-Media Carotídeo , Humanos , Placa Aterosclerótica/diagnóstico por imagen , Medición de Riesgo , Accidente Cerebrovascular/diagnóstico por imagen
14.
Cardiovasc Diagn Ther ; 9(5): 439-461, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31737516

RESUMEN

BACKGROUND: Stroke is in the top three leading causes of death worldwide. Non-invasive monitoring of stroke can be accomplished via stenosis measurements. The current conventional image-based methods for these measurements are not accurate and reliable. They do not incorporate shape and intelligent learning component in their design. METHODS: In this study, we propose a deep learning (DL)-based methodology for accurate measurement of stenosis in common carotid artery (CCA) ultrasound (US) scans using a class of AtheroEdge system from AtheroPoint, USA. Three radiologists manually traced the lumen-intima (LI) for the near and the far walls, respectively, which served as a gold standard (GS) for training the DL-based model. Three DL-based systems were developed based on three types of GS. RESULTS: IRB approved (Toho University, Japan) 407 US scans from 204 patients were collected. The risk was characterized into three classes: low, moderate, and high-risk. The area-under-curve (AUC) corresponding to three DL systems using receiver operating characteristic (ROC) analysis computed were: 0.90, 0.94 and 0.86, respectively. CONCLUSIONS: Novel DL-based strategy showed reliable, accurate and stable stenosis severity index (SSI) measurements.

15.
Front Biosci (Landmark Ed) ; 24(3): 392-426, 2019 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-30468663

RESUMEN

Deep learning (DL) is affecting each and every sphere of public and private lives and becoming a tool for daily use. The power of DL lies in the fact that it tries to imitate the activities of neurons in the neocortex of human brain where the thought process takes place. Therefore, like the brain, it tries to learn and recognize patterns in the form of digital images. This power is built on the depth of many layers of computing neurons backed by high power processors and graphics processing units (GPUs) easily available today. In the current scenario, we have provided detailed survey of various types of DL systems available today, and specifically, we have concentrated our efforts on current applications of DL in medical imaging. We have also focused our efforts on explaining the readers the rapid transition of technology from machine learning to DL and have tried our best in reasoning this paradigm shift. Further, a detailed analysis of complexities involved in this shift and possible benefits accrued by the users and developers.


Asunto(s)
Algoritmos , Diagnóstico por Imagen/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Aprendizaje Automático , Redes Neurales de la Computación , Encéfalo/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética/métodos , Neoplasias/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos
16.
Med Biol Eng Comput ; 57(2): 543-564, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30255236

RESUMEN

Manual ultrasound (US)-based methods are adapted for lumen diameter (LD) measurement to estimate the risk of stroke but they are tedious, error prone, and subjective causing variability. We propose an automated deep learning (DL)-based system for lumen detection. The system consists of a combination of two DL systems: encoder and decoder for lumen segmentation. The encoder employs a 13-layer convolution neural network model (CNN) for rich feature extraction. The decoder employs three up-sample layers of fully convolution network (FCN) for lumen segmentation. Three sets of manual tracings were used during the training paradigm leading to the design of three DL systems. Cross-validation protocol was implemented for all three DL systems. Using the polyline distance metric, the precision of merit for three DL systems over 407 US scans was 99.61%, 97.75%, and 99.89%, respectively. The Jaccard index and Dice similarity of DL lumen segmented region against three ground truth (GT) regions were 0.94, 0.94, and 0.93 and 0.97, 0.97, and 0.97, respectively. The corresponding AUC for three DL systems was 0.95, 0.91, and 0.93. The experimental results demonstrated superior performance of proposed deep learning system over conventional methods in literature. Graphical abstract ᅟ.


Asunto(s)
Arterias Carótidas/fisiopatología , Diabetes Mellitus/fisiopatología , Accidente Cerebrovascular/fisiopatología , Anciano , Aprendizaje Profundo , Femenino , Humanos , Aprendizaje Automático , Masculino , Redes Neurales de la Computación , Estudios Retrospectivos , Medición de Riesgo/métodos , Ultrasonografía/métodos
17.
Comput Methods Programs Biomed ; 176: 173-193, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31200905

RESUMEN

OBJECTIVE: A colon microarray data is a repository of thousands of gene expressions with different strengths for each cancer cell. It is necessary to detect which genes are responsible for cancer growth. This study presents an exhaustive comparative study of different machine learning (ML) systems which serves two major purposes: (a) identification of high risk differential genes using statistical tests and (b) development of a ML strategy for predicting cancer genes. METHODS: Four statistical tests namely: Wilcoxon sign rank sum (WCSRS), t test, Kruskal-Wallis (KW), and F-test were adapted for cancerous gene identification using their p-values. The extracted gene set was used to classify cancer patients using ten classifiers namely: linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), naïve Bayes (NB), Gaussian process classification (GPC), support vector machine (SVM), artificial neural network (ANN), logistic regression (LR), decision tree (DT), Adaboost (AB), and random forest (RF). Performance was then evaluated using cross-validation protocols and standardized metrics viz. accuracy (ACC) and area under the curve (AUC). RESULTS: The colon cancer dataset consists of 2000 genes from 62 patients (40 cancer vs. 22 control). The overall mean ACC of our ML system using all four statistical tests and all ten classifiers was 90.50%. The ML system showed an ACC of 99.81% using a combination WCSRS test and RF-based classifier. This is an improvement of 8% over previously published values in literature. CONCLUSIONS: RF-based model with statistical tests for detection of high risk genes showed the best performance for accurate cancer classification in multi-center clinical trials.


Asunto(s)
Colon/metabolismo , Neoplasias del Colon/metabolismo , Aprendizaje Automático , Análisis de Matrices Tisulares/métodos , Área Bajo la Curva , Teorema de Bayes , Árboles de Decisión , Análisis Discriminante , Perfilación de la Expresión Génica , Humanos , Modelos Logísticos , Modelos Estadísticos , Redes Neurales de la Computación , Distribución Normal , Oncogenes , Análisis de Regresión , Riesgo , Sensibilidad y Especificidad , Máquina de Vectores de Soporte
18.
Med Biol Eng Comput ; 57(7): 1553-1566, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30989577

RESUMEN

Today, the 10-year cardiovascular risk largely relies on conventional cardiovascular risk factors (CCVRFs) and suffers from the effect of atherosclerotic wall changes. In this study, we present a novel risk calculator AtheroEdge Composite Risk Score (AECRS1.0), designed by fusing CCVRF with ultrasound image-based phenotypes. Ten-year risk was computed using the Framingham Risk Score (FRS), United Kingdom Prospective Diabetes Study 56 (UKPDS56), UKPDS60, Reynolds Risk Score (RRS), and pooled composite risk (PCR) score. AECRS1.0 was computed by measuring the 10-year five carotid phenotypes such as IMT (ave., max., min.), IMT variability, and total plaque area (TPA) by fusing eight CCVRFs and then compositing them. AECRS1.0 was then benchmarked against the five conventional cardiovascular risk calculators by computing the receiver operating characteristics (ROC) and area under curve (AUC) values with a 95% CI. Two hundred four IRB-approved Japanese patients' left/right common carotid arteries (407 ultrasound scans) were collected with a mean age of 69 ± 11 years. The calculators gave the following AUC: FRS, 0.615; UKPDS56, 0.576; UKPDS60, 0.580; RRS, 0.590; PCRS, 0.613; and AECRS1.0, 0.990. When fusing CCVRF, TPA reported the highest AUC of 0.81. The patients were risk-stratified into low, moderate, and high risk using the standardized thresholds. The AECRS1.0 demonstrated the best performance on a Japanese diabetes cohort when compared with five conventional calculators. Graphical abstract AECRS1.0: Carotid ultrasound image phenotype-based 10-year cardiovascular risk calculator. The figure provides brief overview of the proposed carotid image phenotype-based 10-year cardiovascular risk calculator called AECRS1.0. AECRS1.0 was also benchmarked against five conventional cardiovascular risk calculators (Framingham Risk Score (FRS), United Kingdom Prospective Diabetes Study 56 (UKPDS56), UKPDS60, Reynolds Risk Score (RRS), and pooled composite risk (PCR) score).


Asunto(s)
Enfermedades Cardiovasculares/etiología , Arterias Carótidas/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador/métodos , Ultrasonografía/métodos , Anciano , Anciano de 80 o más Años , Pueblo Asiatico , Arterias Carótidas/patología , Grosor Intima-Media Carotídeo , Estenosis Carotídea/diagnóstico por imagen , Estenosis Carotídea/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Curva ROC , Factores de Riesgo
19.
Front Biosci (Elite Ed) ; 11(1): 166-185, 2019 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-31136971

RESUMEN

Wilson's disease (WD) is an autosomal recessive disorder which is caused by poor excretion of copper in mammalian cells. In this review, various issues such as effective characterization of ATP7B genes, scope of gene network topology in genetic analysis, pattern recognition using different computing approaches and fusion possibilities in imaging and genetic dataset are discussed vividly. We categorized this study into three major sections: (A) WD genetics, (B) diagnosis guidelines and (3) treatment possibilities. We addressed the scope of advanced mathematical modelling paradigms for understanding common genetic sequences and dominating WD imaging biomarkers. We have also discussed current state-of-the-art software models for genetic sequencing. Further, we hypothesized that involvement of machine and deep learning techniques in the context of WD genetics and image processing for precise classification of WD. These computing procedures signify changing roles of various data transformation techniques with respect to supervised and unsupervised learning models.


Asunto(s)
ATPasas Transportadoras de Cobre/genética , Aprendizaje Profundo , Degeneración Hepatolenticular/diagnóstico por imagen , Degeneración Hepatolenticular/genética , Degeneración Hepatolenticular/terapia , Humanos
20.
Comput Biol Med ; 108: 182-195, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-31005010

RESUMEN

PURPOSE: Conventional cardiovascular risk factors (CCVRFs) and carotid ultrasound image-based phenotypes (CUSIP) are independently associated with long-term risk of cardiovascular (CV) disease. In this study, 26 cardiovascular risk (CVR) factors which consisted of a combination of CCVRFs and CUSIP together were ranked. Further, an optimal risk calculator using AtheroEdge composite risk score (AECRS1.0) was designed and benchmarked against seven conventional CV risk (CVR) calculators. METHODS: Two types of ranking were performed: (i) ranking of 26 CVR factors and (ii) ranking of eight types of 10-year risk calculators. In the first case, multivariate logistic regression was used to compute the odds ratio (OR) and in the second, receiver operating characteristic curves were used to evaluate the performance of eight types of CVR calculators using SPSS23.0 and MEDCALC12.0 with validation against STATA15.0. RESULTS: The left and right common carotid arteries (CCA) of 202 Japanese patients were examined to obtain 404 ultrasound scans. CUSIP ranked in the top 50% of the 26 covariates. Intima-media thickness variability (IMTV) and IMTV10yr were the most influential carotid phenotypes for left CCA (OR = 250, P < 0.0001 and OR = 207, P < 0.0001 respectively) and right CCA (OR = 1614, P < 0.0001 and OR = 626, P < 0.0001 respectively). However, for the mean CCA, AECRS1.0 and AECRS1.010yr reported the most highly significant OR among all the CVR factors (OR = 1.073, P < 0.0001 and OR = 1.104, P < 0.0001). AECRS1.010yr also reported highest area-under-the-curve (AUC = 0.904, P < 0.0001) compared to seven types of conventional calculators. Age and glycated haemoglobin reported highest OR (1.96, P < 0.0001 and 1.05, P = 0.012) among all other CCVRFs. CONCLUSION: AECRS1.010yr demonstrated the best performance due to presence of CUSIP and ranked at the first place with highest AUC.


Asunto(s)
Arteria Carótida Común , Modelos Cardiovasculares , Accidente Cerebrovascular , Factores de Edad , Anciano , Anciano de 80 o más Años , Pueblo Asiatico , Arteria Carótida Común/diagnóstico por imagen , Arteria Carótida Común/metabolismo , Arteria Carótida Común/fisiopatología , Femenino , Humanos , Japón , Masculino , Persona de Mediana Edad , Medición de Riesgo , Accidente Cerebrovascular/sangre , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/fisiopatología , Ultrasonografía
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