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1.
JMIR Aging ; 7: e50537, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38386279

RESUMO

BACKGROUND: The rise in life expectancy is associated with an increase in long-term and gradual cognitive decline. Treatment effectiveness is enhanced at the early stage of the disease. Therefore, there is a need to find low-cost and ecological solutions for mass screening of community-dwelling older adults. OBJECTIVE: This work aims to exploit automatic analysis of free speech to identify signs of cognitive function decline. METHODS: A sample of 266 participants older than 65 years were recruited in Italy and Spain and were divided into 3 groups according to their Mini-Mental Status Examination (MMSE) scores. People were asked to tell a story and describe a picture, and voice recordings were used to extract high-level features on different time scales automatically. Based on these features, machine learning algorithms were trained to solve binary and multiclass classification problems by using both mono- and cross-lingual approaches. The algorithms were enriched using Shapley Additive Explanations for model explainability. RESULTS: In the Italian data set, healthy participants (MMSE score≥27) were automatically discriminated from participants with mildly impaired cognitive function (20≤MMSE score≤26) and from those with moderate to severe impairment of cognitive function (11≤MMSE score≤19) with accuracy of 80% and 86%, respectively. Slightly lower performance was achieved in the Spanish and multilanguage data sets. CONCLUSIONS: This work proposes a transparent and unobtrusive assessment method, which might be included in a mobile app for large-scale monitoring of cognitive functionality in older adults. Voice is confirmed to be an important biomarker of cognitive decline due to its noninvasive and easily accessible nature.


Assuntos
Disfunção Cognitiva , Fala , Humanos , Idoso , Feminino , Masculino , Disfunção Cognitiva/diagnóstico , Estudos Transversais , Itália/epidemiologia , Idoso de 80 Anos ou mais , Fala/fisiologia , Espanha/epidemiologia , Testes de Estado Mental e Demência , Aprendizado de Máquina , Algoritmos
2.
Comput Biol Med ; 144: 105333, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35279425

RESUMO

After publishing an in-depth study that analyzed the ability of computerized methods to assist or replace human experts in obtaining carotid intima-media thickness (CIMT) measurements leading to correct therapeutic decisions, here the same consortium joined to present technical outlooks on computerized CIMT measurement systems and provide considerations for the community regarding the development and comparison of these methods, including considerations to encourage the standardization of computerized CIMT measurements and results presentation. A multi-center database of 500 images was collected, upon which three manual segmentations and seven computerized methods were employed to measure the CIMT, including traditional methods based on dynamic programming, deformable models, the first order absolute moment, anisotropic Gaussian derivative filters and deep learning-based image processing approaches based on U-Net convolutional neural networks. An inter- and intra-analyst variability analysis was conducted and segmentation results were analyzed by dividing the database based on carotid morphology, image signal-to-noise ratio, and research center. The computerized methods obtained CIMT absolute bias results that were comparable with studies in literature and they generally were similar and often better than the observed inter- and intra-analyst variability. Several computerized methods showed promising segmentation results, including one deep learning method (CIMT absolute bias = 106 ± 89 µm vs. 160 ± 140 µm intra-analyst variability) and three other traditional image processing methods (CIMT absolute bias = 139 ± 119 µm, 143 ± 118 µm and 139 ± 136 µm). The entire database used has been made publicly available for the community to facilitate future studies and to encourage an open comparison and technical analysis (https://doi.org/10.17632/m7ndn58sv6.1).


Assuntos
Artérias Carótidas , Espessura Intima-Media Carotídea , Artérias Carótidas/diagnóstico por imagem , Artéria Carótida Primitiva/diagnóstico por imagem , Humanos , Ultrassonografia/métodos , Ultrassonografia Doppler
3.
Ultrasound Med Biol ; 47(8): 2442-2455, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33941415

RESUMO

Common carotid intima-media thickness (CIMT) is a commonly used marker for atherosclerosis and is often computed in carotid ultrasound images. An analysis of different computerized techniques for CIMT measurement and their clinical impacts on the same patient data set is lacking. Here we compared and assessed five computerized CIMT algorithms against three expert analysts' manual measurements on a data set of 1088 patients from two centers. Inter- and intra-observer variability was assessed, and the computerized CIMT values were compared with those manually obtained. The CIMT measurements were used to assess the correlation with clinical parameters, cardiovascular event prediction through a generalized linear model and the Kaplan-Meier hazard ratio. CIMT measurements obtained with a skilled analyst's segmentation and the computerized segmentation were comparable in statistical analyses, suggesting they can be used interchangeably for CIMT quantification and clinical outcome investigation. To facilitate future studies, the entire data set used is made publicly available for the community at http://dx.doi.org/10.17632/fpv535fss7.1.


Assuntos
Algoritmos , Artérias Carótidas/diagnóstico por imagem , Espessura Intima-Media Carotídea , Idoso , Sistemas Computacionais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ultrassonografia
4.
Artigo em Inglês | MEDLINE | ID: mdl-33999819

RESUMO

Recent studies have suggested that textural characteristics of the intima-media complex (IMC) may be more useful than the intima-media thickness (IMT) in evaluating cardiovascular risk. The primary aim of our study was to investigate the association between texture features of the common carotid IMC and prevalent clinical cardiovascular disease (CVD). The secondary aim was to determine whether IMT and IMC texture features vary between the left and right carotid arteries. The study was performed on 2208 longitudinal-section ultrasound images of the left (L) and right (R) common carotid artery (CCA), acquired from 569 men and 535 women out of which 125 had clinical CVD. L and R sides of the IMC were intensity normalized and despeckled. The IMC was semiautomatically delineated for all images using a semiautomated segmentation system, and 61 different texture features were extracted. The corresponding IMT semiautomated measurements (mean±SD) of the L and R sides were 0.73±0.21 mm/0.69±0.19 mm for the normal population and 0.83±0.17 mm/0.79±0.18 mm for those with CVD. IMC texture features did not differ between the right- and left-hand sides. Several texture features were independent predictors of the presence of CVD. The multivariate logistic regression analysis combining age, IMT, and texture features produced a receiver operating characteristic curve with an area under the curve of 89%. A correct classification rate of 77% for separating the normal subject (NOR) versus CVD subjects was achieved using the support vector machine classifier with a combination of clinical features, IMT, and extracted texture features. Texture features provide additional information on the presence of clinical CVD, which is over and above that provided by conventional risk factors or IMT alone. The value of IMC texture features in the prediction of future cardiovascular events should be tested in prospective studies.


Assuntos
Doenças Cardiovasculares , Espessura Intima-Media Carotídea , Doenças Cardiovasculares/diagnóstico por imagem , Doenças Cardiovasculares/epidemiologia , Artéria Carótida Primitiva/diagnóstico por imagem , Feminino , Humanos , Masculino , Prevalência , Estudos Prospectivos , Ultrassonografia
5.
Magn Reson Imaging ; 73: 192-202, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32890673

RESUMO

OBJECTIVE: There is a clinical interest in identifying normal appearing white matter (NAWM) areas in brain T2-weighted (T2W) MRI scans in multiple sclerosis (MS) subjects. These areas are susceptible to disease development and areas need to be studied in order to find potential associations between texture feature changes and disease progression. METHODS: The subjects investigated had a first demyelinating event (Clinically Isolated Syndrome-CIS) at baseline (Time0), and the NAWM0 (i.e. NAWM at Time0) of the brain tissue was subsequently converted to demyelinating plaques (as evaluated in a follow up MRI at Time6-12). 38 untreated subjects that had developed a CIS, had brain MRI scans within an interval of 6-12 months (Time6-12 at follow-up). An experienced MS neurologist manually delineated the demyelinating lesions at Time0 (L0) and at Time6-12 (L6-12). Areas in the Time6-12 MRI scans, where new lesions had been developed, were mapped back to their corresponding NAWM areas on the Time0 MR scans (ROIS0). In addition, contralateral ROIs of similar size and shape were segmented on the same images at Time0 (ROISC0) to form an intra-subject control group. Following that, texture features were extracted from all prescribed areas and MS lesions. RESULTS: Texture features were used as input into Support Vector Machine (SVM) models to differentiate between the following: NAWM0 vs ROISC0, NAWM0 vs NAWM6-12, NAWM0 vs L0, NAWM6-12 vs L6-12, ROIS0 vs L0, ROIS0 vs L6-12 and ROIS0 vs ROISC0, where the corresponding % correct classifications scores were 89%, 95%, 98%, 92%, 85%, 90% and 65% respectively. CONCLUSIONS: Texture features may provide complementary information for following up the development and progression of MS disease. Future work will investigate the proposed method on more subjects.


Assuntos
Imageamento por Ressonância Magnética , Esclerose Múltipla/diagnóstico por imagem , Esclerose Múltipla/patologia , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Adulto , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Máquina de Vetores de Suporte
6.
Comput Methods Programs Biomed ; 194: 105517, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32446038

RESUMO

BACKGROUND AND OBJECTIVE: Ultrasound diaphragmatic muscle motion characteristics may provide useful information about normal or abnormal diaphragmatic function and indicate diaphragmatic weakness, or paralysis. In the present work we propose and evaluate an integrated semi-automated analysis system for the quantitative analysis of ultrasonic motion from ultrasound diaphragmatic videos. METHODS: The proposed system was evaluated in simulated videos and in 13 patients, four of whom patients were mechanically ventilated. The major steps of the methodology were as follows: video normalization, despeckle filtering, generation of an M-Mode image, snakes segmentation, and motion measurements. RESULTS: The following manual (-/) vs semi-automated (/-), (median±IQR) measurements, which are routinely carried out by the experts, for assessing the severity of the disease, were computed. For the simulated videos the diaphragmatic excursion was 1.80±0.00 cm / 1.76±0.03 cm. For all the real ultrasound videos investigated in this study the following measurements were computed: (i) diaphragmatic excursion: 0.84±0.15 cm / 0.83±0.14 cm, (ii) inspiration time (Tinsp): 0.71±0.18 sec / 0.70±0.15 sec, (iii) total breathing time for one cycle (Ttot): 1.71±0.37 sec / 1.67±0.37 sec, (iv) diaphragmatic curve slope: 1.29±0.36 cm/sec / 1.27±0.36 cm/sec, and (v) relaxation rate (RR): 0.82±0.17 cm/sec / 0.82±0.18 cm/sec. CONCLUSIONS: Manual and semi-automated measurements were very close with non-statistical significant differences and strong correlations between them. It is anticipated that the proposed system might be useful in the clinical practice in the assessment and follow up of patients with diaphragmatic weakness or paralysis and aid in the separation of normal and abnormal diaphragmatic motion. Further validation and additional experimentation in a larger sample of videos and different patient groups is required.


Assuntos
Estado Terminal , Diafragma , Diafragma/diagnóstico por imagem , Humanos , Movimento (Física) , Ultrassonografia
7.
IEEE J Transl Eng Health Med ; 6: 2700710, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30405977

RESUMO

Measurements of ultrasound diaphragmatic motion, amplitude, force, and velocity of contraction may provide important and essential information about diaphragmatic fatigue, weakness, or paralysis. In this paper, we propose and evaluate a semi-automated analysis system for measuring the diaphragmatic motion and estimating the maximum relaxation rate (MRR_SAUS) from ultrasound M-mode images of the diaphragmatic muscle. The system was evaluated on 27 M-mode ultrasound images of the diaphragmatic muscle [20 with no resistance (NRES) and 7 with resistance (RES)]. We computed semi-automated ultrasound MRR measurements on all NRES/RES images, using the proposed system (MRR_SAUS = 3.94 ± 0.91/4.98 ± 1.98 [1/s]), and compared them with the manual measurements made by a clinical expert (MRR_MUS = 2.36 ± 1.19/5.8 ± 2.1 [1/s],) and those made by a reference manual method (MRR_MB = 3.93 ± 0.89/3.73 ± 0.52 [1/sec], performed manually with the Biopac system. MRR_SAUS and MRR_MB measurements were not statistically significantly different for NRES and RES subjects but were significantly different with the MRR-MUS measurements made by the clinical expert. It is anticipated that the proposed system might be used in the future in the clinical practice in the assessment and follow up of patients with diaphragmatic weakness or paralysis. It may thus potentially help to understand post-operative pulmonary dysfunction or weaning failure from mechanical ventilation. Further validation and additional experimentation in a larger sample of images and different patient groups is required for further validating the proposed system.

8.
IEEE J Transl Eng Health Med ; 5: 1800509, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29021922

RESUMO

The objective of this paper was to investigate texture feature variability in ultrasound video of the carotid artery during the cardiac cycle in an attempt to define new discriminatory biomarkers of the vulnerable plaque. More specifically, in this paper, 120 longitudinal ultrasound videos, acquired from 40 normal (N) subjects from the common carotid artery and 40 asymptomatic (A) and 40 symptomatic (S) subjects from the proximal internal carotid artery were investigated. The videos were intensity normalized and despeckled, and the intima-media complex (IMC) (from the N subjects) and the atherosclerotic carotid plaques (from the A and S subjects) were segmented from each video, in order to extract the M-mode image, and the texture features associated with cardiac states of systole and diastole. The main results of this paper can be summarized as follows: 1) texture features varied significantly throughout the cardiac cycle with significant differences identified between the cardiac systolic and cardiac diastolic states; 2) gray scale median was significantly higher at cardiac systole versus diastole for the N, A, and S groups investigated; 3) plaque texture features extracted during the cardiac cycle at the systolic and diastolic states were statistically significantly different between A and S subjects (and can thus be used to discriminate between A and S subjects successfully). The combination of systolic and diastolic features yields better performance than those alone. It is anticipated that the proposed system may aid the physician in clinical practice in classifying between N, A, and S subjects using texture features extracted from ultrasound videos of IMC and carotid artery plaque. However, further evaluation has to be carried out with more videos and additional features.

9.
PLoS One ; 12(9): e0184201, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28926591

RESUMO

Squamous cell carcinoma of the head and neck (SCCHN) comprises a large group of cancers in the oral cavity and nasopharyngeal area that typically arise in older males in association with alcohol/tobacco usage. Within the oral cavity, the mobile tongue is the most common site for tumour development. The incidence of tongue squamous cell carcinoma (TSCC) is increasing in younger people, which has been suggested to associate with a viral aetiology. Two common human oncogenic viruses, human papilloma virus (HPV) and Epstein-Barr virus (EBV) are known causes of certain types of SCCHN, namely the oropharynx and nasopharynx, respectively. EBV infects most adults worldwide through oral transmission and establishes a latent infection, with sporadic productive viral replication and release of virus in the oral cavity throughout life. In view of the prevalence of EBV in the oral cavity and recent data indicating that it infects tongue epithelial cells and establishes latency, we examined 98 cases of primary squamous cell carcinoma of the mobile tongue and 15 cases of tonsillar squamous cell carcinoma for the presence of EBV-encoded RNAs (EBERs), EBV DNA and an EBV-encoded protein, EBNA-1. A commercially available in situ hybridisation kit targeting EBER transcripts (EBER-ISH) showed a positive signal in the cytoplasm and/or nuclei of tumour cells in 43% of TSCCs. However, application of control probes and RNase A digestion using in-house developed EBER-ISH showed identical EBER staining patterns, indicating non-specific signals. PCR analysis of the BamH1 W repeat sequences did not identify EBV genomes in tumour samples. Immunohistochemistry for EBNA-1 was also negative. These data exclude EBV as a potential player in TSCC in both old and young patients and highlight the importance of appropriate controls for EBER-ISH in investigating EBV in human diseases.


Assuntos
Carcinoma de Células Escamosas/virologia , Herpesvirus Humano 4/genética , Neoplasias da Língua/virologia , Neoplasias Tonsilares/virologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/patologia , DNA Viral/análise , DNA Viral/metabolismo , Antígenos Nucleares do Vírus Epstein-Barr/genética , Antígenos Nucleares do Vírus Epstein-Barr/metabolismo , Herpesvirus Humano 4/isolamento & purificação , Humanos , Imuno-Histoquímica , Hibridização In Situ , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Neoplasias da Língua/patologia , Neoplasias Tonsilares/patologia , Adulto Jovem
10.
Immun Inflamm Dis ; 5(4): 541-550, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28805308

RESUMO

OBJECTIVES: Recurrent respiratory papillomatosis (RRP) is a relatively rare, chronic disease caused by Human Papilloma Virus (HPV) 6 and 11, and characterized by wart-like lesions in the airway affecting voice and respiratory function. The majority of HPV infections are asymptomatic and resolve spontaneously, however, some individuals are afflicted with persistent HPV infections. Failure to eliminate HPV 6 and 11 due to a defect immune responsiveness to these specific genotypes is proposed to play a major role in the development of RRP. METHODS: We performed a phenotypic characterization of peripheral blood mononuclear cells (PBMC) collected from 16 RRP patients and 12 age-matched healthy controls, using immunoflow cytometry, and monoclonal antibodies against differentiation and activation markers. The cytokine mRNA profile of monocytes, T helper-, T cytotoxic-, and NK cells was assessed using RT-qPCR cytokine analysis, differentiating between Th1-, Th2-, Th3/regulatory-, and inflammatory immune responses. RESULTS: We found a dominance of cytotoxic T cells, activated NK cells, and high numbers of stressed MIC A/B expressing lymphocytes. There was an overall suppression of cytokine mRNA production and an aberrant cytokine mRNA profile in the activated NK cells. CONCLUSION: These findings demonstrate an immune dysregulation with inverted CD4+ /CD8+ ratio and aberrant cytokine mRNA production in RRP patients, compared to healthy controls.


Assuntos
Citocinas/genética , Citotoxicidade Imunológica , Expressão Gênica , Linfócitos/imunologia , Linfócitos/metabolismo , Papiloma/etiologia , Neoplasias do Sistema Respiratório/etiologia , Adolescente , Adulto , Biomarcadores , Estudos de Casos e Controles , Citocinas/metabolismo , Feminino , Papillomavirus Humano 11 , Papillomavirus Humano 6 , Humanos , Imunofenotipagem , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Masculino , Papiloma/diagnóstico , Papiloma/metabolismo , Neoplasias do Sistema Respiratório/diagnóstico , Neoplasias do Sistema Respiratório/metabolismo , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Adulto Jovem
11.
Sci Rep ; 6: 32579, 2016 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-27572959

RESUMO

Epigenetic modifications are essential regulators of biological processes. Decreased DNA methylation of OAS2 (2'-5'-Oligoadenylate Synthetase 2), encoding an antiviral protein, has been seen in psoriasis. To provide further insight into the epigenetic regulation of OAS2, we performed pyrosequencing to detect OAS2 DNA methylation status at 11 promoter and first exon located CpG sites in psoriasis (n = 12) and two common subtypes of squamous cell carcinoma (SCC) of the head and neck: tongue (n = 12) and tonsillar (n = 11). Compared to corresponding controls, a general hypomethylation was seen in psoriasis. In tongue and tonsillar SCC, hypomethylation was found at only two CpG sites, the same two sites that were least demethylated in psoriasis. Despite differences in the specific residues targeted for methylation/demethylation, OAS2 expression was upregulated in all conditions and correlations between methylation and expression were seen in psoriasis and tongue SCC. Distinctive methylation status at four successively located CpG sites within a genomic area of 63 bp reveals a delicately integrated epigenetic program and indicates that detailed analysis of individual CpGs provides additional information into the mechanisms of epigenetic regulation in specific disease states. Methylation analyses as clinical biomarkers need to be tailored according to disease-specific sites.


Assuntos
2',5'-Oligoadenilato Sintetase/genética , Carcinoma de Células Escamosas/genética , Ilhas de CpG , Epigênese Genética , Neoplasias de Cabeça e Pescoço/genética , Psoríase/genética , Neoplasias da Língua/genética , Neoplasias Tonsilares/genética , 2',5'-Oligoadenilato Sintetase/metabolismo , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Estudos de Casos e Controles , Metilação de DNA , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Regiões Promotoras Genéticas , Psoríase/metabolismo , Psoríase/patologia , Estudos Retrospectivos , Neoplasias da Língua/metabolismo , Neoplasias da Língua/patologia , Neoplasias Tonsilares/metabolismo , Neoplasias Tonsilares/patologia
12.
Acta Otolaryngol ; 135(10): 1058-64, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26004132

RESUMO

CONCLUSION: Recurrent respiratory papillomatosis (RRP) patients with high surgical treatment frequency (≥ 1/year, HF) were significantly younger and had a more widespread laryngeal disease compared to a low frequency treated group (< 1 treatment/year, LF). This study confirms the existence of a clinical RRP group, not primarily related to HPV sub-type, but more care-intensive and in need of more vigilant follow-up. OBJECTIVES: RRP is associated with high morbidity due to its influence on breathing and voice. The purpose of this study was to characterize RRP patients in northern Sweden and investigate possible predictor factors affecting therapeutic needs. METHOD: Patients from the regional referral area (northern Sweden) were categorized for age, disease duration, juvenile or adult onset, profile of disease development, number of surgical sessions in relation to disease duration, laryngeal deposition of papilloma, gender, and HPV sub-types, in order to identify patients with increased need for frequent surgical treatment. RESULTS: The median age of the RRP patients (n = 48) was 44.5 years; 34 (71%) were males and 14 (29%) females, most were infected with HPV 6. Patients with high surgical treatment frequency/year were significantly younger and showed more widespread papillomatous vegetation in the larynx, compared to the low frequency treated group.


Assuntos
Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/epidemiologia , Infecções Respiratórias/epidemiologia , Adulto , Biópsia , Endoscopia , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/virologia , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/virologia , Índice de Gravidade de Doença , Suécia/epidemiologia
13.
Oncol Lett ; 10(6): 3565-3572, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26788170

RESUMO

The incidence rate of tonsillar cancer is increasing worldwide. The current study identifies a parallel increase in the incidence of tonsillar cancer, human papilloma virus (HPV) and p16 expression among a population from northern Sweden, a sparsely populated area, confirming the strong association between p16 and HPV infection in tonsillar tissue. Data from the Swedish Cancer Registry was assessed to identify cases of tonsillar cancer in the northern territorial area of Sweden. HPV DNA was extracted from paraffin embedded diagnostic biopsies and detected by polymerase chain reaction using general primers Gp5+/6+ and CpI/IIG. Expression of p16 was identified by immunochemistry. Patients were grouped into urban or rural residence categories. A total of 214 cases were identified, comprising 155 (72.4%) men and 59 (27.6%) women, and 65 of these patients, who presented between 2000 and 2012, were analyzed. The overall median age for the analyzed patients was 58 years; 48 (74%) were males (median age, 57.5 years) and 17 (26%) were females (median age, 65 years). Of the 65 specimens, 59 (91%) were positive for HPV, and 62 (95%) expressed p16. The incidence of tonsillar cancer in the cohort demonstrated a 2-fold increase between 1990 and 2013; specifically, a 2.7-fold increase was observed in men whilst the female group exhibited only a small increase. These findings demonstrate a strong association between p16 expression and HPV infection in tonsillar malignancies. The incidence of HPV-positive tonsillar cancer has increased in recent years, even in sparsely populated regions, as demonstrated in northern Sweden.

14.
IEEE J Biomed Health Inform ; 19(2): 668-76, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24951708

RESUMO

The recent emergence of the high-efficiency video coding (HEVC) standard promises to deliver significant bitrate savings over current and prior video compression standards, while also supporting higher resolutions that can meet the clinical acquisition spatiotemporal settings. The effective application of HEVC to medical ultrasound necessitates a careful evaluation of strict clinical criteria that guarantee that clinical quality will not be sacrificed in the compression process. Furthermore, the potential use of despeckle filtering prior to compression provides for the possibility of significant additional bitrate savings that have not been previously considered. This paper provides a thorough comparison of the use of MPEG-2, H.263, MPEG-4, H.264/AVC, and HEVC for compressing atherosclerotic plaque ultrasound videos. For the comparisons, we use both subjective and objective criteria based on plaque structure and motion. For comparable clinical video quality, experimental evaluation on ten videos demonstrates that HEVC reduces bitrate requirements by as much as 33.2% compared to H.264/AVC and up to 71% compared to MPEG-2. The use of despeckle filtering prior to compression is also investigated as a method that can reduce bitrate requirements through the removal of higher frequency components without sacrificing clinical quality. Based on the use of three despeckle filtering methods with both H.264/AVC and HEVC, we find that prior filtering can yield additional significant bitrate savings. The best performing despeckle filter (DsFlsmv) achieves bitrate savings of 43.6% and 39.2% compared to standard nonfiltered HEVC and H.264/AVC encoding, respectively.


Assuntos
Compressão de Dados/métodos , Ultrassonografia/métodos , Gravação em Vídeo/métodos , Bases de Dados Factuais , Humanos , Placa Aterosclerótica/diagnóstico por imagem , Telemedicina
15.
IEEE J Transl Eng Health Med ; 3: 1900410, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-27170894

RESUMO

The intima-media thickness (IMT) of the common carotid artery (CCA) is an established indicator of cardiovascular disease (CVD). There have been reports about the difference between the left and the right sides of the CCA IMT and their relation with CVD. In this paper, we propose an automated system based on image normalization, speckle reduction filtering, and snakes segmentation, for segmenting the CCA, perform IMT measurements, and provide the differences between the left and the right sides. The study was performed on 1104 longitudinal-section ultrasound images acquired from 568 men and 536 women out of which 125 had cardiovascular symptoms (CVD). A cardiovascular expert manually delineated the IMT for the normal and the CVD groups. The corresponding (normal versus CVD) IMT mean ± standard deviation values for the left and the right sides were 0.74 ± 0.24 versus 0.87 ± 0.24 mm and 0.70 ± 0.17 versus 0.80 ± 0.18 mm, respectively. The main findings of this paper can be summarized as follows: 1) there was no significant difference between the CCA left side IMT and the right side IMT. These findings suggest that the measurement of the CCA IMT on one side only is needed for the normal group (and this is in agreement with other studies); 2) there were statistical significant differences for the IMT measurements between the normal group and the CVD group for both the left and the right sides; 3) there was an increasing linear relationship of the left and the right IMT measurements with age for the normal group; and to a lesser extend for the CVD group; 4) no statistical significant differences were found between the manual and the automated IMT measurements for both sides; and 5) the best result for classification disease modeling, using support vector machines, to discriminate between the normal and the CVD groups was a 64%±3.5% correct classifications score when using both the left and the right IMT automated measurements. Further research is required for estimating differences and similarities between left and right intima media complex structure and morphology and their variability with texture features for differentiating between the normal and the CVD group.

16.
Med Biol Eng Comput ; 52(12): 1073-93, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25284219

RESUMO

The determination of the wall thickness [intima-media thickness (IMT)], the delineation of the atherosclerotic carotid plaque, the measurement of the diameter in the common carotid artery (CCA), as well as the grading of its stenosis are important for the evaluation of the atherosclerosis disease. All these measurements are also considered to be significant markers for the clinical evaluation of the risk of stroke. A number of CCA segmentation techniques have been proposed in the last few years either for the segmentation of the intima-media complex (IMC), the lumen of the CCA, or for the atherosclerotic carotid plaque from ultrasound images or videos of the CCA. The present review study proposes and discusses the methods and systems introduced so far in the literature for performing automated or semi-automated segmentation in ultrasound images or videos of the CCA. These are based on edge detection, active contours, level sets, dynamic programming, local statistics, Hough transform, statistical modeling, neural networks, and an integration of the above methods. Furthermore, the performance of these systems is evaluated and discussed based on various evaluation metrics. We finally propose the best performing method that can be used for the segmentation of the IMC and the atherosclerotic carotid plaque in ultrasound images and videos. We end the present review study with a discussion of the different image and video CCA segmentation techniques, future perspectives, and further extension of these techniques to ultrasound video segmentation and wall tracking of the CCA. Future work on the segmentation of the CCA will be focused on the development of integrated segmentation systems for the complete segmentation of the CCA as well as the segmentation and motion analysis of the plaque and or the IMC from ultrasound video sequences of the CCA. These systems will improve the evaluation, follow up, and treatment of patients affected by advanced atherosclerosis disease conditions.


Assuntos
Artéria Carótida Primitiva/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Túnica Íntima/diagnóstico por imagem , Gravação em Vídeo/métodos , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Ultrassonografia
17.
Comput Biol Med ; 53: 220-9, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25173810

RESUMO

The objective of this study was to investigate differences in intima-media thickness (IMT) and diameter (D) measurements of the common carotid artery (CCA) in ultrasound imaging in normal subjects and renal failure disease (RFD) patients. Manual measurements by two experts and automated segmentation measurements (based on snakes and active contour models (ACM)) were carried out on 73 normal subjects, and 80 RFD patients. Statistical analysis was carried out using the Wilcoxon rank-sum test at p<0.05. Results demonstrated that the mean IMT and D measurements were significantly higher for the RFD group versus the normal group. Moreover, there was no significant difference between the manual and automated measurements. The ACM segmentation was slightly more accurate than segmentation based on snakes. Further work is needed to validate these findings on a larger group of subjects.


Assuntos
Artéria Carótida Primitiva/diagnóstico por imagem , Espessura Intima-Media Carotídea , Processamento de Imagem Assistida por Computador/métodos , Insuficiência Renal/fisiopatologia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Insuficiência Renal/epidemiologia
18.
Comput Methods Programs Biomed ; 114(1): 109-24, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24560276

RESUMO

Ultrasound imaging of the common carotid artery (CCA) is a non-invasive tool used in medicine to assess the severity of atherosclerosis and monitor its progression through time. It is also used in border detection and texture characterization of the atherosclerotic carotid plaque in the CCA, the identification and measurement of the intima-media thickness (IMT) and the lumen diameter that all are very important in the assessment of cardiovascular disease (CVD). Visual perception, however, is hindered by speckle, a multiplicative noise, that degrades the quality of ultrasound B-mode imaging. Noise reduction is therefore essential for improving the visual observation quality or as a pre-processing step for further automated analysis, such as image segmentation of the IMT and the atherosclerotic carotid plaque in ultrasound images. In order to facilitate this preprocessing step, we have developed in MATLAB(®) a unified toolbox that integrates image despeckle filtering (IDF), texture analysis and image quality evaluation techniques to automate the pre-processing and complement the disease evaluation in ultrasound CCA images. The proposed software, is based on a graphical user interface (GUI) and incorporates image normalization, 10 different despeckle filtering techniques (DsFlsmv, DsFwiener, DsFlsminsc, DsFkuwahara, DsFgf, DsFmedian, DsFhmedian, DsFad, DsFnldif, DsFsrad), image intensity normalization, 65 texture features, 15 quantitative image quality metrics and objective image quality evaluation. The software is publicly available in an executable form, which can be downloaded from http://www.cs.ucy.ac.cy/medinfo/. It was validated on 100 ultrasound images of the CCA, by comparing its results with quantitative visual analysis performed by a medical expert. It was observed that the despeckle filters DsFlsmv, and DsFhmedian improved image quality perception (based on the expert's assessment and the image texture and quality metrics). It is anticipated that the system could help the physician in the assessment of cardiovascular image analysis.


Assuntos
Artéria Carótida Primitiva/diagnóstico por imagem , Software , Anisotropia , Humanos , Ultrassonografia
19.
Artigo em Inglês | MEDLINE | ID: mdl-24402898

RESUMO

The robust border identification of atherosclerotic carotid plaque, the corresponding degree of stenosis of the common carotid artery (CCA), and also the characteristics of the arterial wall, including plaque size, composition, and elasticity, have significant clinical relevance for the assessment of future cardiovascular events. To facilitate the follow-up and analysis of the carotid stenosis in serial clinical investigations, we propose and evaluate an integrated system for the segmentation of atherosclerotic carotid plaque in ultrasound videos of the CCA based on video frame normalization, speckle reduction filtering, M-mode state-based identification, parametric active contours, and snake segmentation. Initially, the cardiac cycle in each video is identified and the video M-mode is generated, thus identifying systolic and diastolic states. The video is then segmented for a time period of at least one full cardiac cycle. The algorithm is initialized in the first video frame of the cardiac cycle, with human assistance if needed, and the moving atherosclerotic plaque borders are tracked and segmented in the subsequent frames. Two different initialization methods are investigated in which initial contours are estimated every 20 video frames. In the first initialization method, the initial snake contour is estimated using morphology operators; in the second initialization method, the Chan-Vese active contour model is used. The performance of the algorithm is evaluated on 43 real CCA digitized videos from B-mode longitudinal ultrasound segments and is compared with the manual segmentations of an expert, available every 20 frames in a time span of 3 to 5 s, covering, in general, 2 cardiac cycles. The segmentation results were very satisfactory, according to the expert objective evaluation, for the two different methods investigated, with true-negative fractions (TNF-specificity) of 83.7 ± 7.6% and 84.3 ± 7.5%; true-positive fractions (TPF-sensitivity) of 85.42 ± 8.1% and 86.1 ± 8.0%; and between the ground truth and the proposed segmentation method, kappa indices (KI) of 84.6% and 85.3% and overlap indices of 74.7% and 75.4%. The segmentation contours were also used to compute the cardiac state identification and radial, longitudinal, and shear strain indices for the CCA wall and plaque between the asymptomatic and symptomatic groups were investigated. The results of this study show that the integrated system investigated in this study can be successfully used for the automated video segmentation of the CCA plaque in ultrasound videos.


Assuntos
Técnicas de Imagem de Sincronização Cardíaca/métodos , Artérias Carótidas/diagnóstico por imagem , Estenose das Carótidas/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Reconhecimento Automatizado de Padrão/métodos , Ultrassonografia/métodos , Gravação em Vídeo/métodos , Algoritmos , Feminino , Humanos , Aumento da Imagem/métodos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Integração de Sistemas
20.
Acta Otolaryngol ; 134(4): 401-6, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24433057

RESUMO

CONCLUSION: The frequency of operations, age at onset, gender and subtype of the human papilloma virus (HPV) may be used as factors to predict voice disability. OBJECTIVES: Patients with recurrent respiratory papillomatosis (RRP) are characterized by morbid consequences due to a lifelong repetitive influence on voice and breathing ability and the need for recurrent surgical treatments. The aim of the study was to measure the quality of voice and life using evaluated and validated questionnaires in a northern Sweden RRP population. METHODS: A total of 27 consecutive patients with RRP (age 21-71 years, median 47 years) were evaluated 3 months postoperatively (CO2 laser treatment) using the voice handicap index (VHI) and SF-36 questionnaires to assess the impact on life and voice in an RRP population. The values were compared to historical normative data, VHI ≤ 20. RESULTS: Patients that underwent more than one operation per year were younger (p = 0.028) than those treated less frequently. The mean VHItotal score in patients with RRP was 39.3, indicating a statistically significant impairment of voice quality (p < 0.001) as compared with normal subjects. Voice dysfunction was observed in 21 patients (78%). Significantly lower values than the normal population regarding the quality of life in patients with RRP were obtained in the domain of social functioning (p = 0.029). Females, patients with frequent surgical treatment sessions and patients with the high-risk HPV types scored significantly lower in several domains of the quality of life assessment as compared with normal subjects. The results should be interpreted with caution due to the limited number of subjects.


Assuntos
Infecções por Papillomavirus/fisiopatologia , Qualidade de Vida , Infecções Respiratórias/fisiopatologia , Qualidade da Voz/fisiologia , Adulto , Idoso , DNA Viral/análise , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Papillomaviridae/genética , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/virologia , Reação em Cadeia da Polimerase , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/virologia , Índice de Gravidade de Doença , Estroboscopia , Inquéritos e Questionários , Suécia/epidemiologia , Adulto Jovem
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