Tomographic MR (Magnetic Resonance) and sonographic biosignal processing are important non-invasive diagnostic methods used in a medicine. A noise added into processed data by an amplifier of tomograph receiving part and by circuits of sonograph is resulting in a body organ diagnosis degradation. Image data are stored in a standardized DICOM medical file format. Methods using wavelet analysis for noise suppression in image data have been designed and their comparation with classical methods has been made in this work. The MATLAB was utilized for data processing and data rewriting back to the DICOM format.

The aim of this masters thesis is design and implement an appropriate method for highlighting MR images and the identification of rough edges to provide for division of controlled areas. To this purpose is possible to use the Wavelet analysis. For the simulation environment I using MATLAB entviroment, where introduce the comparison for different types of de-noising and too for different mother wavelets. These methods will be implemented on various MR images of termoromandibular joint.

This master’s thesis is focused on anonymization of ultrasound data in DICOM format. Haar wavelet belonging to Daubechies wavelet family is used to detect text areas in the image. Extraction of the text from the image is done using a free tool - tesseract OCR Engine. Finally, detected text is compared to sensitive data from DICOM metadata using Levenshtein - edit distance algorithm.

Picture Archiving and Communication Systems (PACS) have been traditionally constrained to the premises of the healthcare provider. This has limited the availability of these systems in many parts of the world and mandated major costs in infrastructure for those who employ them. Public cloud services could be a solution that eases the cost of ownership and provides greater flexibility for PACS implementations. This could make it possible to bring medical imaging services to places where it was previously unavailable and reduce the costs associated with these services for those who utilize them. Moving these systems to public cloud infrastructure requires that an authentication and encryption policy for communications is established within the PACS environment to mitigate the risks incurred by using the Internet for the communication of medical data. This thesis proposes a framework which can be used to create an authenticated and encrypted channel to secure the communications with a cloud-based PACS. This framework uses the Transport Layer Security (TLS) protocol and X.509 certificates to create a secured channel. An enterprise style PKI is used to provide a trust model to authorize endpoints to access the system. The validity of this framework was tested by creating a prototype cloud-based PACS with secured communications. Using this framework will provide a system based on trusted industry standards which will protect the confidentiality and integrity of medical data in transit when using a cloud-based PACS service.

Η διατριβή εισάγει μια νέα ανοιχτή αρχιτεκτονική για επικοινωνία ιατρικών απεικονιστικών εξετάσεων, η οποία παρουσιάζεται μέσω ενός νέου PACS-ιστού που εστιάζει στην τηλεακτινολογία. Η προτεινόμενη αρχιτεκτονική είναι βασισμένη στις αρχές της επέκτασης ιστού του DICOM που είναι η υπηρεσία/πρωτόκολλο WADO (Πρόσβαση μέσω Ιστού σε Επίμονα Στοιχεία Εξέτασης DICOM). Η αρχιτεκτονική ενσωματώνει υπηρεσίες DICOM και κοινές υπηρεσίες Διαδικτύου (βασισμένες στον ιστό, στο FTP, και στο ηλεκτρονικό ταχυδρομείο). Η διατριβή επίσης επεκτείνει την δυνατότητα πρόσβασης της WADO σε ολόκληρη την ιεραρχία DICOM (Ασθενής, Διαγνωστική Εξέταση, Σειρά Εξέτασης και Στοιχείο Εξέτασης). Η επέκταση της WADO καλείται WADA (Πρόσβαση μέσω Ιστού σε Συστήματα Αρχειοθέτησης DICOM). Σε αντιδιαστολή με τη WADO, η WADA περιλαμβάνει ένα πρόσθετο εσωτερικό μηχανισμό αναζήτησης και υποστηρίζει την υποβολή ιατρικής διάγνωσης. Το σύνολο των προτεινόμενων υπηρεσιών υποστηρίζει την εκτεταμένη πρόσβαση και είναι ενσωματωμένο σε μια δομή τριών επιπέδων (πελάτη, εξυπηρετητή και δεδομένων) που εξασφαλίζει ευελιξία πρόσβασης, κινητικότητα χρηστών και ενισχυμένη ασφάλεια δεδομένων. Η πλευρά των εξυπηρετητών της αρχιτεκτονικής παρέχει διεπαφές των υπηρεσιών μέσω ιστού και διασφαλισμένο χώρο προσωρινής αποθήκευσης που καλείται Περιοχές Χρηστών. Η παρούσα διατριβή μελετά επίσης υποδομή υπολογιστικού πλέγματος για την αρχιτεκτονική του PACS-ιστού και ένα συνεργατικό σχήμα μεταξύ PACS και RIS για ολοκληρωμένη διαχείριση απεικονιστικών εξετάσεων μέσω ιστού. Η προτεινόμενη αρχιτεκτονική υλοποιήθηκε πιλοτικά κυρίως με τεχνολογίες βασισμένες σε Java και προϊόντα συμβατά με πρότυπα. Η υλοποιημένη αρχιτεκτονική αξιολογήθηκε από μηχανικούς σε συνεργασία με ιατρούς. / The dissertation introduces a new open architecture for medical imaging communication illustrating a novel web Picture Archiving and Communication System (PACS), which focuses on teleradiology. The proposed architecture is based on the concept of the web extension of Digital Imaging and Communication in Medicine (DICOM) that is the Web Access to DICOM Persistent Objects (WADO) protocol/service. The architecture integrates DICOM services and common Internet services (based on web, FTP, and e-mail). The dissertation also extends WADO access capability to the whole DICOM hierarchy (Patient, Study, Series and Object). The extended WADO is called Web Access to DICOM Archives (WADA). WADA, as opposed to WADO, includes an extra internal query mechanism and support of medical reports submission. The whole of the proposed services support the extended access and are integrated into a three-tier structure (client, server and data tiers) which ensures flexibility in access, user mobility and enhanced data security. The server site of the architecture provides service interfaces through web and invulnerable space for temporary storage, called as User Domains. This dissertation also studies a computing grid infrastructure for the web PACS architecture and a cooperative scheme between PACS and Radiology Information System (RIS) for integrated administration of imaging examinations through web. The proposed architecture is pilot implemented using mainly Java-based technologies and standard-compliant products. Τhe implemented architecture is evaluated by engineers in collaboration with doctors.

O objetivo desse trabalho é apresentar as características de um Sistema de Apoio ao Diagnóstico em Sistema Hospitalar Suportando Busca por Imagens Similares, a ser desenvolvido e implantado no Hospital das Clínicas de Ribeirão Preto. A recuperação de imagens baseada no conteúdo é uma área de pesquisa que tem evoluído bastante nos últimos anos. Assim, um sistema de busca e obtenção de imagens, utilizando tal técnica, deve ser extensível aos novos algoritmos de extração de características e métodos de indexação. A extração de características de imagens, tais como informações de cor, textura, forma e o relacionamento entre elas são utilizadas para descrever o conteúdo das imagens. Essas características são então utilizadas para indexar e possibilitar a comparação de imagens no processo de recuperação. O sistema proposto utilizará um método de indexação de dados recém-desenvolvido – a Slim-tree – para indexar as características extraídas das imagens. Através desse método o Sistema de Apoio ao Diagnóstico possibilitará a consulta por conteúdo em imagens médicas. / This works presents the main characteristics of a diagnosis support system based on image similarity search for medical applications. This system was developed to be used in the Clinical Hospital of Ribeirao Preto of the University of Sao Paulo. The content-based image retrieval (CBIR) researching area has evolved greatly in the last years. Thus, a CBIR system should be able to incorporate the new techniques developed, such as, new feature extraction algorithms and indexing methods among others. Traditionally, the main features extracted from images to get the image essence are color, texture, shape and the relationship among them. Therefore, such features describe the images under analysis, and are used to index and to compare images during the content-based retrieval process. The proposed system takes advantage of a new metric access method - the Slim-tree, which allows the indexing and the retrieval of the images through their extracted features.

This work explores a novel vision model based coding approach to encode medical images at a perceptually lossless quality, within the framework of the JPEG 2000 coding engine. Perceptually lossless encoding offers the best of both worlds, delivering images free of visual distortions and at the same time providing significantly greater compression ratio gains over its information lossless counterparts. This is achieved through a visual pruning function, embedded with an advanced model of the human visual system to accurately identify and to efficiently remove visually irrelevant/insignificant information. In addition, it maintains bit-stream compliance with the JPEG 2000 coding framework and subsequently is compliant with the Digital Communications in Medicine standard (DICOM). Equally, the pruning function is applicable to other Discrete Wavelet Transform based image coders, e.g., The Set Partitioning in Hierarchical Trees. Further significant coding gains are ex ploited through an artificial edge segmentation algorithm and a novel arithmetic pruning algorithm. The coding effectiveness and qualitative consistency of the algorithm is evaluated through a double-blind subjective assessment with 31 medical experts, performed using a novel 2-staged forced choice assessment that was devised for medical experts, offering the benefits of greater robustness and accuracy in measuring subjective responses. The assessment showed that no differences of statistical significance were perceivable between the original images and the images encoded by the proposed coder.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work, a study has been done about the procedures for evaluating the quality of image display devices (monitors) used in radio-anomaly, based on the analysis of the luminance characteristic curve versus the lowest just noticiable difference (JND), taking into account the time use of such equipment. The evaluated devices were of different of manufactures, models, series and had different resolutions. The evaluation of the quality of monitors exerts a strong influence on the image quality. For this evaluation of quality control, in addition to methods and instruments traditionally employed, an alternative method was used to measure luminance using electric and photometric quantities, which was validated by comparison with data obtained using a photometer, which is a standard meter of luminance. The quality control tests for evaluation of diffuse reflection, specular reflection, internal reflection or blurring, resolution, noise, luminance and contrast response and luminance uniformity were performed on devices with standard TG18 test images in DICOM GSDF format, with several shades of gray. These images are made available by the American Association of Physicists in Medicine (AAPM). The results were analyzed based on the limits established for primary and secondary monitors established in quality control protocols for radiodiagnostics, including one from the AAPM and others from Europe. In the analyzes, the illuminance of the environments in which the monitors were taken into account. The qualitative and quantitative results were correlated with the time of use of the display devices. The software used to view the test images were Radiant DICOM, Micro DICOM and Isyte Radiology. The results demonstrate the relevance of monitoring the use time of these devices, classified as primary (diagnostic use) and secondary (visualization only). It was verified among the monitored monitors, used in general radiology, that those with resolution between 2 and 5 megapixels can be classified as primary until a certain time of use; Among the analyzed devices with more than 50,000 hours of use, some demonstrate a behavior equivalent to that of secondary monitors. Monitoring the temporal evolution of the use of a device in radiodiagnosis is important so that errors in medical diagnosis are avoided. Not only are the higher resolution devices suitable for diagnostic reports but also those with lower resolution since their image display parameters comply with quality control recommendations. / Neste trabalho foi realizado um estudo sobre procedimentos de avalia¸c˜ao da qualidade de dispositivos de exibi¸c˜ao de imagem (monitores) utilizados em radiodiagn´ostico, a partir da an´alise da curva caracter´ıstica de luminˆancia versus a menor diferen¸ca detect´avel de contraste (JND), levando em conta o tempo de uso desses equipamentos. Os dispositivos avaliados foram de diferentes marcas de fabrica¸c˜ao, modelos, s´eries e possu´ıam resolu¸c˜oes distintas. A avalia¸c˜ao da qualidade de monitores exerce forte influˆencia na qualidade de imagem. Para essa avalia¸c˜ao de controle de qualidade, al´em dos m´etodos e instrumentos tradicionalmente empregados, foi empregado um m´etodo alternativo para medi¸c˜ao de luminˆancia utilizando grandezas el´etricas e fotom´etricas, que foram validadas por compara¸c˜ao aos dados obtidos utilizando-se um fotˆometro, que ´e medidor padr˜ao de luminˆancia. Os testes de controle de qualidade para avalia¸c˜ao de reflex˜ao difusa, reflex ˜ao especular, reflex˜ao interna ou velamento, resolu¸c˜ao, ru´ıdo, resposta de luminˆancia e contraste e uniformidade de luminˆancia foram realizados nos dispositivos com imagens padr˜ao teste TG18 em formato DICOM GSDF, com v´arios tons de cinza. Essas imagens s˜ao disponibilizadas pela Associa¸c˜ao Americana dos F´ısicos em Medicina (AAPM). Os resultados foram analisados com base nos limites estabelecidos para monitores prim´arios e secund´arios estabelecidos em protocolos de controle de qualidade para radiodiagn´ostico, incluindo um da AAPM e outros da Europa. Nas an´alises, levou-se em considera¸c˜ao a ilumin ˆancia dos ambientes em que se encontravam os monitores. Os resultados qualitativos e quantitativos foram correlacionados ao tempo de uso dos dispositivos de exibi¸c˜ao. Os softwares utilizados para visualiza¸c˜ao das imagens testes foram o Radiant DICOM, Micro DICOM e o Isyte Radio-logy. Os resultados demonstram a relevˆancia do acompanhamento do tempo de uso desses dispositivos, que podem ser classificados como prim´arios (uso em diagn´ostico) e secund´arios (visualiza¸c˜ao apenas). Foi verificado entre os monitores aferidos, utilizados em radiologia geral, que aqueles com resolu¸c˜ao entre 2 e 5 megapixels podem ser classificados como prim´arios at´e certo tempo de uso; entre os dispositivos analisados com mais de 50.000 horas de uso, alguns demonstram um comportamento equivalente ao de monitores secund´arios. O acompanhamento da evolu¸c˜ao temporal do uso de um dispositivo no radiodiagn´ostico ´e importante, para que se evite erros no diagn´ostico m´edico. N˜ao s´o os dispositivos de maior resolu¸c˜ao s˜ao adequados para laudos em radiodiagn ´ostico, mas tamb´em aqueles com menor resolu¸c˜ao, desde que seus parˆametros de exibi¸c˜ao de imagem estejam de acordo com as recomenda¸c˜oes de controle de qualidade

O objetivo desse trabalho é apresentar as características de um Sistema de Apoio ao Diagnóstico em Sistema Hospitalar Suportando Busca por Imagens Similares, a ser desenvolvido e implantado no Hospital das Clínicas de Ribeirão Preto. A recuperação de imagens baseada no conteúdo é uma área de pesquisa que tem evoluído bastante nos últimos anos. Assim, um sistema de busca e obtenção de imagens, utilizando tal técnica, deve ser extensível aos novos algoritmos de extração de características e métodos de indexação. A extração de características de imagens, tais como informações de cor, textura, forma e o relacionamento entre elas são utilizadas para descrever o conteúdo das imagens. Essas características são então utilizadas para indexar e possibilitar a comparação de imagens no processo de recuperação. O sistema proposto utilizará um método de indexação de dados recém-desenvolvido – a Slim-tree – para indexar as características extraídas das imagens. Através desse método o Sistema de Apoio ao Diagnóstico possibilitará a consulta por conteúdo em imagens médicas. / This works presents the main characteristics of a diagnosis support system based on image similarity search for medical applications. This system was developed to be used in the Clinical Hospital of Ribeirao Preto of the University of Sao Paulo. The content-based image retrieval (CBIR) researching area has evolved greatly in the last years. Thus, a CBIR system should be able to incorporate the new techniques developed, such as, new feature extraction algorithms and indexing methods among others. Traditionally, the main features extracted from images to get the image essence are color, texture, shape and the relationship among them. Therefore, such features describe the images under analysis, and are used to index and to compare images during the content-based retrieval process. The proposed system takes advantage of a new metric access method - the Slim-tree, which allows the indexing and the retrieval of the images through their extracted features.

This thesis deals with design and realization of methods of preprocessing of X-ray images and its storage. In the first part of this thesis, there were designed and implemented methods for preprocessing of series of X-ray images such as averaging after image registration or merging of images to a HDR image using Debevec method. In the following part of the thesis, there was done a literary research of data formats based on which was implemented a library for x-ray images storage. Both implemented methods allow to reduce a random noise by merging a series of images. Application of the Debevec method also allow to increase a dynamic range of image.