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2.
Eur J Case Rep Intern Med ; 10(3): 003783, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36969519

RESUMO

Leptospirosis is a zoonotic infection infrequently reported in non-tropical regions. Although classically described as a biphasic illness, unusual clinical manifestations have been reported, including a previous case of a lung abscess associated with this causative agent. We present the case of a 49-year-old man with a new diagnosis of two liver abscesses associated with leptospirosis. LEARNING POINTS: Leptospirosis is a zoonosis caused by spirochetes of the genus Leptospira; the infection is more commonly reported in tropical regions.Leptospirosis classically manifests as a biphasic illness, the first phase characterized by high fever that coincides with leptospiraemia, followed by a brief period when the patient is afebrile. In the second phase, fever returns, accompanied by jaundice and renal failure.The unusual clinical manifestations of leptospirosis include a previous report of a lung abscess, but despite frequent liver involvement, liver abscess in this context has not previously been described.

3.
BMJ Open Respir Res ; 9(1)2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36198571

RESUMO

This British Thoracic Society Quality Standard for Clinically Significant Bronchiectasis in Adults 2022 aims to encourage good practice by setting standards of high-quality respiratory care that services should follow.


Assuntos
Bronquiectasia , Adulto , Bronquiectasia/terapia , Humanos , Terapia Respiratória , Sociedades Médicas
4.
Radiother Oncol ; 166: 133-136, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34838890

RESUMO

This is a paired prospective comparative cohort study with 58 patients, in order to analyze the clinical LD-WLI in patients with moderate or severe COVID19 pneumonia. The results of this study show that the Radiotherapy could be an option to improve the clinical response for patients with COVID-19.


Assuntos
COVID-19 , COVID-19/radioterapia , Estudos de Coortes , Humanos , Pulmão/efeitos da radiação , Estudos Prospectivos , SARS-CoV-2 , Resultado do Tratamento
5.
Curr Drug Targets ; 22(15): 1706-1715, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33538671

RESUMO

BACKGROUND: The incidence of inflammatory bowel disease (IBD) continues to rise worldwide. Despite the advances in pharmacotherapy, the etiopathogenesis of Crohn's disease (CD) and ulcerative colitis (UC) remains underexplained. The migratory waves are a challenging setting to analyze the evolution of IBD prevalence and to infer its triggering factors. OBJECTIVE: Our study aimed to overview the literature regarding IBD prevalence and phenotype in first- and second-generation migrants Also, we aimed to summarize the migration history and to draw a possible correlation with IBD distribution. METHODS: A non-systematic review was performed following electronic (PubMed and Web of Science) and manual searches on relevant topics. RESULTS: Overall, first-generation migrants tend to maintain the IBD risk of the native country. On the following generation, the risk tends to converge to that of the destination country. Earlier age at migration modulates IBD risk, suggesting that the degree of exposure to environmental and socio-economic factors can be decisive for disease progression. In general, CD needs more time to reach a disease burden similar to that of the host country, indicating that UC may be more affected by nongenetic factors and genetic-nongenetic interactions. CONCLUSION: IBD phenotypes and natural history vary in migrants and according to ethnicity; however, the trends are not consensual among cohorts. Further studies are warranted to analyze the effect of genetic background and environmental risk factors in different ethnic groups, providing evidence to move towards the identification of at-risk individuals, prevention, and earlier diagnosis of IBD.


Assuntos
Colite Ulcerativa , Doença de Crohn , Doenças Inflamatórias Intestinais , Migrantes , Colite Ulcerativa/diagnóstico , Colite Ulcerativa/epidemiologia , Doença de Crohn/epidemiologia , Humanos , Incidência , Doenças Inflamatórias Intestinais/epidemiologia , Fatores de Risco
6.
Curr Drug Targets ; 2020 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-33213340

RESUMO

The article has been withdrawn from the journal "Current Drug Targets" on behalf of the author's request. Bentham Science apologizes to its readers for any inconvenience this may have caused. The Bentham Editorial Policy on Article Withdrawal can be found at https://benthamscience.com/journals/current-drug-targets/editorial-policies/ Bentham Science Disclaimer: It is a condition of publishers that manuscripts submitted to this journal should not be simultaneously submitted or published elsewhere. Furthermore, any data, illustration, structure, or table that has been published elsewhere must be reported, and copyright permission for reproduction must be obtained. Plagiarism is strictly forbidden, and while submitting- ting the article for publication, the authors agree that the publishers have the legal right to take appropriate action against the authors if plagiarism or fabricated information is discovered. By submitting a manuscript the authors agree that the copyright of their article is transferred to the publishers, if and when the article is accepted for publication.

7.
Clin Imaging ; 59(1): 61-67, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31760279

RESUMO

BACKGROUND: Cardiac magnetic resonance imaging (MRI) is an essential imaging method used to assess patients with diseases of the left and right ventricles. Cardiac MRI is the gold standard for right ventricular measurements; however, the most suitable method for volumetric analysis of the right ventricle remains controversial. AIMS: To compare the accuracy of the short axis and four-chamber view segmentation methods in assessing the right ventricle in cardiac MRI studies, to determine the reproducibility of cardiac MR measurements, and to correlate cardiac MR methods with frequently used echocardiographic methods. METHODS: Eighty patients with different clinical indications were studied using a 1.5-Tesla resonance magnetic unit. In all patients, the end-diastolic volume, end-systolic volume, and right ventricle ejection fraction were measured in the short axis and four-chamber views. Twenty-three patients also underwent echocardiography on the same day the cardiac MRI was completed. RESULTS: Cardiac MRI revealed no statistically significant differences in the volume or function of the right ventricle, calculated by the two segmentation methods (p > 0.05). The correlation was excellent between both planes in the assessment of the volume (concordance correlation coefficient [CCC] = 0.97) and the ejection fraction (CCC = 0.90). The correlation was low between the right ventricular ejection fraction and the echocardiographic methods (CCC = 0.02 and CCC = 0.01). CONCLUSION: Right ventricular function in normal ventricles and in dilated ventricles was appropriately measured by cardiac MRI using either of the two segmentation methods. Both methods were highly accurate. However, the correlation with echocardiographic methods was rather poor.


Assuntos
Ventrículos do Coração/anatomia & histologia , Angiografia por Ressonância Magnética/métodos , Adolescente , Adulto , Idoso , Volume Cardíaco/fisiologia , Criança , Ecocardiografia/métodos , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Volume Sistólico/fisiologia , Função Ventricular Direita/fisiologia , Adulto Jovem
8.
Neurosurgery ; 81(4): 595-601, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28327963

RESUMO

BACKGROUND: Flow-diverter technology has become an important stent-based embolization tool in the treatment of complex cerebrovascular pathology. We report here the experience of 4 Spanish centers with using the SILK flow-diverter (SFD) device. OBJECTIVE: To evaluate the safety and efficacy of using the SFD in the endovascular treatment of intracranial aneurysms with complex morphology. METHODS: We retrospectively examined a prospectively maintained database of patients treated with SFD devices between July 2008 and December 2013 at 1 of 4 institutions in Spain. Data regarding patient demographics, aneurysm characteristics, and technical procedure were analyzed. Angiographic and clinical findings were recorded during the procedure and at 12 months postoperatively. RESULTS: A total of 175 SFD devices were implanted in 157 patients (women/men: 119/38; mean, median, and range of age: 56.2, 56.7, and 19-80 years, respectively), who were treated in a delayed manner (3-6 months from the event) for 180 aneurysms (165 unruptured and 15 ruptured). Adverse events (acute and delayed) were observed in 28.7% of cases (45/157), and most were resolved (19.1%; 30/157). Six months after the procedure, total morbidity and mortality were 9.6% (15/157) and 3.2% (5/157), respectively. Long-term imaging follow-up showed complete occlusion, neck remnants, and residual aneurysm in 78.1% (100/128), 14.0% (18/128), and 7.8% (10/128) of cases, respectively. CONCLUSIONS: The SFD device is an effective tool for the treatment of challenging aneurysms, and allows complete occlusion within a year of the procedure in most patients, with morbidity and mortality comparable to those previously reported for similar devices.


Assuntos
Embolização Terapêutica/métodos , Aneurisma Intracraniano/epidemiologia , Aneurisma Intracraniano/terapia , Estatística como Assunto/métodos , Adulto , Idoso , Angiografia Cerebral/métodos , Bases de Dados Factuais/estatística & dados numéricos , Feminino , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Resultado do Tratamento
9.
Int J Comput Assist Radiol Surg ; 12(4): 657-667, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28188483

RESUMO

PURPOSE: The aim of this paper is to describe a project designed to achieve a total integration of different CAD algorithms into the PACS environment by using a wide computing infrastructure. METHODS: The aim is to build a system for the entire region of Galicia, Spain, to make CAD accessible to multiple hospitals by employing different PACSs and clinical workstations. The new CAD model seeks to connect different devices (CAD systems, acquisition modalities, workstations and PACS) by means of networking based on a platform that will offer different CAD services. This paper describes some aspects related to the health services of the region where the project was developed, CAD algorithms that were either employed or selected for inclusion in the project, and several technical aspects and results. RESULTS: We have built a standard-based platform with which users can request a CAD service and receive the results in their local PACS. The process runs through a web interface that allows sending data to the different CAD services. A DICOM SR object is received with the results of the algorithms stored inside the original study in the proper folder with the original images. CONCLUSIONS: As a result, a homogeneous service to the different hospitals of the region will be offered. End users will benefit from a homogeneous workflow and a standardised integration model to request and obtain results from CAD systems in any modality, not dependant on commercial integration models. This new solution will foster the deployment of these technologies in the entire region of Galicia.


Assuntos
Diagnóstico por Computador/métodos , Sistemas de Informação em Radiologia , Algoritmos , Humanos , Fluxo de Trabalho
10.
Eur Radiol ; 27(2): 821-830, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27271922

RESUMO

OBJECTIVES: To demonstrate non-inferiority of iobitridol 350 for coronary CT angiography (CTA) compared to higher iodine content contrast media regarding rate of patients evaluable for the presence of coronary artery stenoses. METHODS: In this multicentre trial, 452 patients were randomized to receive iobitridol 350, iopromide 370 or iomeprol 400 and underwent coronary CTA using CT systems with 64-detector rows or more. Two core lab readers assessed 18 coronary segments per patient regarding image quality (score 0 = non diagnostic to 4 = excellent quality), vascular attenuation, signal and contrast to noise ratio (SNR, CNR). Patients were considered evaluable if no segment had a score of 0. RESULTS: Per-patient, the rate of fully evaluable CT scans was 92.1, 95.4 and 94.6 % for iobitridol, iopromide and iomeprol, respectively. Non-inferiority of iobitridol over the best comparator was demonstrated with a 95 % CI of the difference of [-8.8 to 2.1], with a pre-specified non-inferiority margin of -10 %. Although average attenuation increased with higher iodine concentrations, average SNR and CNR did not differ between groups. CONCLUSIONS: With current CT technology, iobitridol 350 mg iodine/ml is not inferior to contrast media with higher iodine concentrations in terms of image quality for coronary stenosis assessment. KEY POINTS: • Iodine concentration is an important parameter for image quality in coronary CTA. • Contrast enhancement must be balanced against the amount of iodine injected. • Iobitridol 350 is non-inferior compared to CM with higher iodine concentrations. • Higher attenuation with higher iodine concentrations, but no SNR or CNR differences.


Assuntos
Calcinose/diagnóstico por imagem , Angiografia por Tomografia Computadorizada/métodos , Angiografia Coronária/métodos , Estenose Coronária/diagnóstico por imagem , Adulto , Idoso , Meios de Contraste , Doença da Artéria Coronariana/diagnóstico por imagem , Método Duplo-Cego , Feminino , Humanos , Iodo , Iohexol/análogos & derivados , Iopamidol/análogos & derivados , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada Multidetectores/métodos , Tomografia Computadorizada por Raios X/métodos
12.
PLoS One ; 10(7): e0133290, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26177287

RESUMO

Estimating the area of seabed surfaces from pictures or videos is an important problem in seafloor surveys. This task is complex to achieve with moving platforms such as submersibles, towed or remotely operated vehicles (ROV), where the recording camera is typically not static and provides an oblique view of the seafloor. A new method for obtaining seabed surface area estimates is presented here, using the classical set up of two laser devices fixed to the ROV frame projecting two parallel lines over the seabed. By combining lengths measured directly from the image containing the laser lines, the area of seabed surfaces is estimated, as well as the camera's distance to the seabed, pan and tilt angles. The only parameters required are the distance between the parallel laser lines and the camera's horizontal and vertical angles of view. The method was validated with a controlled in situ experiment using a deep-sea ROV, yielding an area estimate error of 1.5%. Further applications and generalizations of the method are discussed, with emphasis on deep-sea applications.


Assuntos
Processamento de Imagem Assistida por Computador , Água do Mar , Imageamento Tridimensional , Lasers , Fenômenos Ópticos , Fotografação/instrumentação , Reprodutibilidade dos Testes , Propriedades de Superfície , Incerteza
13.
Comput Biol Med ; 57: 74-83, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25540830

RESUMO

Accurate determination of the diameter is an important step for diagnosis and follow-up of aortic abnormalities such as aneurysms, caused by dilation of the vessel lumen. In this work we focus on the development of an automatic method for measuring the calibre of the thoracic aorta. The method is based on the application of principal component analysis on normal planes extracted from the aorta to establish the main axis of each section of the vessel. Two experiments were performed in order to test the accuracy and the rotational invariance of the developed method. Accuracy was determined by using a database of 15 clinical cases, where our method and a commercial software, which was considered as the gold standard, were compared. For the rotational invariance check, phantom images in different orientations were obtained and the diameter was measured with the proposed method. For clinical cases, a good agreement was observed between our method and the gold standard. The Bland Altman plots indicated that all of the values were within the acceptable limits of agreement with a bias of 0.2mm between both methods. For phantom cases, an ANOVA test revealed that the results achieved for the data sets acquired for the different orientations were not statistically different (F=1.88, p=0.153), which demonstrates the robustness of the method for rotations. The proposed method is applicable for measuring the diameter in all tested cases, and the results achieved underscored the capability of our approach for automatic characterization of thoracic aortic aneurysms.


Assuntos
Aorta Torácica/diagnóstico por imagem , Aneurisma da Aorta Torácica/diagnóstico por imagem , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos , Idoso , Algoritmos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Imagens de Fantasmas
14.
Comput Aided Surg ; 18(5-6): 109-17, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23879881

RESUMO

This study sought to develop a completely automatic method for image segmentation of the thoracic aorta. We used a total of 4682 images from 10 consecutive patients. The proposed method is based on the use of level set and region growing, automatically initialized using the Hough transform. The results obtained were compared to those of manual segmentation as performed by an external expert radiologist. Concordance between the developed method and manual segmentation ranged from 92.79 to 95.77% in the descending regions of the aorta and from 90.68 to 96.54% in the ascending regions, with a mean value of 93.83% being obtained for total segmentation.


Assuntos
Angiografia , Aorta Torácica/patologia , Aneurisma da Aorta Torácica/patologia , Interpretação de Imagem Assistida por Computador , Imageamento Tridimensional , Tomografia Computadorizada por Raios X , Algoritmos , Aorta Torácica/diagnóstico por imagem , Aneurisma da Aorta Torácica/diagnóstico por imagem , Aneurisma da Aorta Torácica/cirurgia , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão
15.
Diagnostics (Basel) ; 3(2): 271-82, 2013 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-26835680

RESUMO

The purpose of this study was to evaluate the performance of a semiautomatic segmentation method for the anatomical and functional assessment of both ventricles from cardiac cine magnetic resonance (MR) examinations, reducing user interaction to a "mouse-click". Fifty-two patients with cardiovascular diseases were examined using a 1.5-T MR imaging unit. Several parameters of both ventricles, such as end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF), were quantified by an experienced operator using the conventional method based on manually-defined contours, as the standard of reference; and a novel semiautomatic segmentation method based on edge detection, iterative thresholding and region growing techniques, for evaluation purposes. No statistically significant differences were found between the two measurement values obtained for each parameter (p > 0.05). Correlation to estimate right ventricular function was good (r > 0.8) and turned out to be excellent (r > 0.9) for the left ventricle (LV). Bland-Altman plots revealed acceptable limits of agreement between the two methods (95%). Our study findings indicate that the proposed technique allows a fast and accurate assessment of both ventricles. However, further improvements are needed to equal results achieved for the right ventricle (RV) using the conventional methodology.

16.
Mar Pollut Bull ; 64(9): 1884-94, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22770531

RESUMO

This study provides data concerning the hydrography and water chemistry of the Atlantic region between 29-38° N and 27-31° W, and establishes background values for dissolved Cu, Cd, Pb and As. Three water masses were identified: the Eastern North Atlantic Central Water (ENACW), the Mediterranean Water (MW) and the North Atlantic Deep Water (NADW). The ENACW exhibits a clear meridional gradient of temperature and salinity, with comparatively high values at the southern sites and lower values on the Azores platform. The ENACW, which includes the euphotic zone, also had comparatively high concentrations of oxygen and lower concentrations of nutrients and metals. The Cu, Cd and Pb results suggest that new background concentrations for OSPAR Region V (the Wider Atlantic) should be established as follows: 0.15-13 nM for Cu, 0.05-1.4 nM for Cd and 0.03-5 nM for Pb. The background concentrations of As for OSPAR Region V should be 7-28 nM.


Assuntos
Monitoramento Ambiental , Água do Mar/química , Poluentes Químicos da Água/análise , Açores , Poluição Química da Água/estatística & dados numéricos
17.
Comput Biol Med ; 39(10): 921-33, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19660744

RESUMO

We have developed a computer-aided diagnosis (CAD) system to detect pulmonary nodules on thin-slice helical computed tomography (CT) images. We have also investigated the capability of an iris filter to discriminate between nodules and false-positive findings. Suspicious regions were characterized with features based on the iris filter output, gray level and morphological features, extracted from the CT images. Functions calculated by linear discriminant analysis (LDA) were used to reduce the number of false-positives. The system was evaluated on CT scans containing 77 pulmonary nodules. The system was trained and evaluated using two completely independent data sets. Results for a test set, evaluated with free-response receiver operating characteristic (FROC) analysis, yielded a sensitivity of 80% at 7.7 false-positives per scan.


Assuntos
Automação , Neoplasias Pulmonares/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Algoritmos , Análise Discriminante , Reações Falso-Positivas , Humanos , Curva ROC
18.
Comput Biol Med ; 37(2): 214-26, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16620805

RESUMO

We propose a system to detect malignant masses on mammograms. We investigated the behavior of an iris filter at different scales. After iris filter was applied, suspicious regions were segmented by means of an adaptive threshold. Suspected regions were characterized with features based on the iris filter output and, gray level, texture, contour-related, and morphological features extracted from the image. A backpropagation neural network classifier was trained to reduce the number of false positives. The system was developed and evaluated with two completely independent data sets. Results for a test set of 66 malignant and 49 normal cases, evaluated with free-response receiver operating characteristic analysis, yielded a sensitivity of 88% and 94% at 1.02 false positives per image for lesion-based and case-based evaluation, respectively. Results suggest that the proposed method could help radiologists as a second reader in mammographic screening.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Processamento de Imagem Assistida por Computador , Mamografia/métodos , Reações Falso-Positivas , Feminino , Humanos
19.
IEEE Trans Inf Technol Biomed ; 10(2): 354-61, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16617624

RESUMO

The functionalities of the JPEG2000 standard have led to its incorporation into digital imaging and communications in medicine (DICOM), which makes this compression method available for medical systems. In this study, we evaluated the compression of mammographic images with JPEG2000 (16 : 1, 20 : 1, 40 : 1, 60.4 : 1, 80: 1, and 106 : 1) for applications with a computer-aided detection (CAD) system for clusters of microcalcifications. Jackknife free-response receiver operating characteristic (JAFROC) analysis indicated that differences in the detection of clusters of microcalcifications were not statistically significant for uncompressed versus 16: 1 (T = -0.7780; p = 0.4370), 20 : 1 (T = 1.0361; p = 0.3007), and 40 : 1 (T = 1.6966; p = 0.0904); and statistically significant for uncompressed versus 60.4 : 1 (T = 5.8883; p < 0.008), 80 : 1 (T = 7.8414; p < 0.008), and 106 : 1 (T = 17.5034; p = < 0.008). Although there is a small difference in peak signal-to-noise ratio (PSNR) between compression ratios, the true-positive (TP) and false-positive (FP) rates, and the free-response receiver operating characteristic (FROC), figure of merit values considerably decreased from a 60 : 1 compression ratio. The performance of the CAD system is significantly reduced when using images compressed at ratios greater than 40 : 1 with JPEG2000 compared to uncompressed images. Mammographic images compressed up to 20 : 1 provide a percentage of correct detections by our CAD system similar to uncompressed images, regardless of the characteristics of the cluster. Further investigation is required to determine how JPEG2000 affects the detectability of clusters of microcalcifications as a function of their characteristics.


Assuntos
Inteligência Artificial , Doenças Mamárias/diagnóstico por imagem , Calcinose/diagnóstico por imagem , Compressão de Dados/métodos , Mamografia/métodos , Intensificação de Imagem Radiográfica/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Compressão de Dados/normas , Feminino , Guias como Assunto , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
20.
Radiology ; 237(2): 450-7, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16244253

RESUMO

PURPOSE: To assess the effects of two irreversible wavelet-based compression algorithms--Joint Photographic Experts Group (JPEG) 2000 and object-based set partitioning in hierarchical trees (SPIHT)--on the detection of clusters of microcalcifications and masses on digitized mammograms. MATERIALS AND METHODS: The use of the images in this retrospective image-collection study was approved by the institutional review board, and patient informed consent was not required. One hundred twelve mammographic images (28 with one or two clusters of microcalcifications, 19 with one mass, 17 with both abnormal findings, and 48 with normal findings) obtained in 60 women who ranged in age from 25 to 79 years were digitized and compressed at 40:1 and 80:1 by using the JPEG2000 and object-based SPIHT methods. Five experienced radiologists were asked to locate and rate clusters of microcalcifications and masses on the original and compressed images in a free-response receiver operating characteristic (FROC) data acquisition paradigm. Observer performance was evaluated with the jackknife FROC method. RESULTS: The mean FROC figures of merit for detecting clusters of microcalcifications, masses, and both radiographic findings on uncompressed images were 0.80, 0.81, and 0.72, respectively. With object-based SPIHT 80:1 compression, the corresponding values were larger than the values for uncompressed images by 0.005, 0.009, and -0.005, respectively. The 95% confidence interval for the differences in figures of merit between compressed and uncompressed images was -0.039, 0.033 for the microcalcification finding; -0.055, 0.034 for the mass finding; and -0.039, 0.030 for both findings. Because each of these confidence intervals includes zero, no significant difference in detection accuracy between uncompressed and object-based SPIHT 80:1 compression was observed at a P value of 5%. The F test of the null hypothesis that all of the modes (uncompressed and four compressed modes) were equivalent yielded the following results: F = 0.255, P = .903 for the microcalcification finding; F = 0.340, P = .848 for the mass finding; and F = 0.122, P = .975 for both findings. CONCLUSION: To within the accuracy of these measurements, lossy compression of digital mammographic data at 80:1 with JPEG2000 or the object-based SPIHT algorithm can be performed without decreasing the rate of detection of clusters of microcalcifications and masses.


Assuntos
Mamografia , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Adulto , Idoso , Algoritmos , Feminino , Humanos , Pessoa de Meia-Idade , Curva ROC , Estudos Retrospectivos , Interface Usuário-Computador
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