Normalizing Heterogeneous Medical Imaging Data to Measure the Impact of Radiation Dose.

The production of medical imaging is a continuing trend in healthcare institutions. Quality assurance for planned radiation exposure situations (e.g. X-ray, computer tomography) requires examination-specific set-ups according to several parameters, such as patient's age and weight, body region and clinical indication. These data are normally stored in several formats and with different nomenclatures, which hinder the continuous and automatic monitoring of these indicators and the comparison between several institutions and equipment. This article proposes a framework that aggregates, normalizes and provides different views over collected indicators. The developed tool can be used to improve the quality of radiologic procedures and also for benchmarking and auditing purposes. Finally, a case study and several experimental results related to radiation exposure and productivity are presented and discussed.

A framework for integration of heterogeneous medical imaging networks.

Medical imaging is increasing its importance in matters of medical diagnosis and in treatment support. Much is due to computers that have revolutionized medical imaging not only in acquisition process but also in the way it is visualized, stored, exchanged and managed. Picture Archiving and Communication Systems (PACS) is an example of how medical imaging takes advantage of computers. To solve problems of interoperability of PACS and medical imaging equipment, the Digital Imaging and Communications in Medicine (DICOM) standard was defined and widely implemented in current solutions. More recently, the need to exchange medical data between distinct institutions resulted in Integrating the Healthcare Enterprise (IHE) initiative that contains a content profile especially conceived for medical imaging exchange: Cross Enterprise Document Sharing for imaging (XDS-i). Moreover, due to application requirements, many solutions developed private networks to support their services. For instance, some applications support enhanced query and retrieve over DICOM objects metadata. This paper proposes anintegration framework to medical imaging networks that provides protocols interoperability and data federation services. It is an extensible plugin system that supports standard approaches (DICOM and XDS-I), but is also capable of supporting private protocols. The framework is being used in the Dicoogle Open Source PACS.

Screening radiation exposure for quality assurance.

Quality assurance for planned radiation exposure situations (e.g. Digital Radiography, Computed Tomography or Radio Fluoroscopic studies) requires the application of examination-specific scans protocols. These are tailored to patient age or size, body region and clinical indication for ensuring that the dose applied to each patient is as low as reasonably achievable for the clinical purpose of the image acquisition (ALARA principle). The European legal framework--2013/59/EURATOM--points that health authorities will be more pervasive on inspecting the dosimetry applied to patients. This paper discusses these legal alterations and presents an interoperable distributed system for dose monitoring, which is compliant with legal procedures and the IHE Radiation Exposure Monitoring profile (REM). The system combines the most representative stakeholders affected and directly interested in the patient radiological protection: patients, radiologists, practitioners, health authorities, and ethics committee. The system is capable of gathering, in real-time, dose information applied to the patient and storing it in a regional or national wide dose registry. The paper addresses which information should such systems hold and which should be accessed, from each stakeholder perspective. Furthermore, the system may detect irregular dose patterns, which could indicate dose abuses, and signal those findings to the appropriate stakeholders.

XDS-I outsourcing proxy: ensuring confidentiality while preserving interoperability.

The interoperability of services and the sharing of health data have been a continuous goal for health professionals, patients, institutions, and policy makers. However, several issues have been hindering this goal, such as incompatible implementations of standards (e.g., HL7, DICOM), multiple ontologies, and security constraints. Cross-enterprise document sharing (XDS) workflows were proposed by Integrating the Healthcare Enterprise (IHE) to address current limitations in exchanging clinical data among organizations. To ensure data protection, XDS actors must be placed in trustworthy domains, which are normally inside such institutions. However, due to rapidly growing IT requirements, the outsourcing of resources in the Cloud is becoming very appealing. This paper presents a software proxy that enables the outsourcing of XDS architectural parts while preserving the interoperability, confidentiality, and searchability of clinical information. A key component in our architecture is a new searchable encryption (SE) scheme-Posterior Playfair Searchable Encryption (PPSE)-which, besides keeping the same confidentiality levels of the stored data, hides the search patterns to the adversary, bringing improvements when compared to the remaining practical state-of-the-art SE schemes.

A centralized platform for geo-distributed PACS management.

Picture Archive and Communication System (PACS) is a globally adopted concept and plays a fundamental role in patient care flow within healthcare institutions. However, the deployment of medical imaging repositories over multiple sites still brings several practical challenges namely related to operation and management (O&M). This paper describes a Web-based centralized console that provides remote monitoring, testing, and management over multiple geo-distributed PACS. The system allows the PACS administrator to define any kind of service or operation, reducing the need for local technicians and providing a 24/7 monitoring solution.

Enabling outsourcing XDS for imaging on the public cloud.

Picture Archiving and Communication System (PACS) has been the main paradigm in supporting medical imaging workflows during the last decades. Despite its consolidation, the appearance of Cross-Enterprise Document Sharing for imaging (XDS-I), within IHE initiative, constitutes a great opportunity to readapt PACS workflow for inter-institutional data exchange. XDS-I provides a centralized discovery of medical imaging and associated reports. However, the centralized XDS-I actors (document registry and repository) must be deployed in a trustworthy node in order to safeguard patient privacy, data confidentiality and integrity. This paper presents XDS for Protected Imaging (XDS-p), a new approach to XDS-I that is capable of being outsourced (e.g. Cloud Computing) while maintaining privacy, confidentiality, integrity and legal concerns about patients' medical information.

Enhancing the many-to-many relations across IHE document sharing communities.

The Integrating Healthcare Enterprise (IHE) initiative is an ongoing project aiming to enable true inter-site interoperability in the health IT field. IHE is a work in progress and many challenges need to be overcome before the healthcare Institutions may share patient clinical records transparently and effortless. Configuring, deploying and testing an IHE document sharing community requires a significant effort to plan and maintain the supporting IT infrastructure. With the new paradigm of cloud computing is now possible to launch software devices on demand and paying accordantly to the usage. This paper presents a framework designed with purpose of expediting the creation of IHE document sharing communities. It provides semi-ready templates of sharing communities that will be customized according the community needs. The framework is a meeting point of the healthcare institutions, creating a favourable environment that might converge in new inter-institutional professional relationships and eventually the creation of new Affinity Domains.

Clustering of distinct PACS archives using a cooperative peer-to-peer network.

To face the demanding requirements of the clinical environment, PACS archives need to be resilient and reliable, supporting high availability and fault tolerance. Often, to ensure no data loss, PACS archives retain two copies of images on separate physical machines, using distributed data storage facilities. However, PACS do not take advantage of the various replicas to improve the transfer rates of medical images. This happens mostly because the DICOM standard does not comply with distributed fetching of image fragments while performing a store. Inspired by this unexplored opportunity, we designed and implemented a new solution that takes advantage of the distributed image replicas and, at the same time, respects the DICOM standard. Our strategy brought significant improvements in the exchange rates, load balancing and availability of installed PACS archives. Moreover, the adopted strategy forms a cluster of PACS archives that transparently enables horizontal scaling, facilitates the creation of backups, and gives to healthcare professionals a unified view of the distributed repositories.