The recent ITIS-ITAB'99 Conference formed an excellent occasion to highlight the concept of the Virtual Medical Worlds as developed in the Euromed project. Dr. Tuomo Kauranne presented the Euromed results from a technical point of view. At the University of Joensuu, the Finnish partners have built a prototype environment with the patient as the focal point. Using Web technology, it is possible to perform remote medical analysis on images stored in a Digital Imaging and Communications in Medicine (DICOM) image database. The DICOM gateway allows the physician to access DICOM images from the Virtual Medical Worlds interface via a simple WWW browser by logging on with a password.
The Virtual Medical Worlds system enables physicians to search for a particular patient and to select data. The patient home page contains non-medical information, such as for instance a careplan or insurance data, general details, medical specialities, and medical records. The research team at Joensuu, which operates under the lead of Dr. Tuomo Kauranne and Dr. Alexander Kolesnikov, decided to apply a server-side HTML-embedded script language, called PHP/FI, which allows items in the database to be created, retrieved, updated and deleted. To enter the WWW-DICOM system, the end-user runs his WWW-browser requesting the PHP/FI scripts via a query form to start consultation or manipulation of the required medical images.
The DICOM image archiving system, which is used for the project, consists of a Web based relational Mini Software Query Language or SQL database filled with records referring to stored DICOM files. The database table structure is based upon a four level hierarchy. The Patient level forms the top level, containing multiple Studies. A Study in turn, comprises one or several Series, but always belonging to a definite Study. The third level Series consists of one or multiple Images, but an Image always forms part of a definite Series. The lowest level is the Image level where Images originating from a single imaging modality, belong to the same Series.
In order to get access to the database, the user activates his WWW-browser to specify the URL of a DICOM Picture Archival Computer System (PACS) workstation. The thus invoked PHP/FI script generates an HTML file, which displays a query form with two fields: Patient name and Patient ID. The user fills out the form and submits his request via the PHP/FI script which enters the search into the relational database to determine the patients who are corresponding to the input criteria. The user selects a patient and obtains a list display of the patient's personal studies, series and images. It is possible to use the system at a local level via intranet, remotely through an extranet, or in general by using the Internet. The whole process is managed on a link level.
Once the images are displayed, the physician can perform a range of image processing procedures by means of special feature detection tools. In this way, the user can convert images from DICOM to JPEG format or transform them in a piecewise-linear manner; sharpen or equalise the data or execute isolines, equidensities and edge detection on it. The processing programmes are written in C and can be loaded from a PHP/FI script. In fact, the PHP/FI script in syntax is similar to C one and forms a Common Gateway Interface (CGI) wrapper language. It is fairly easy to add other image processing and medical analysis facilities without having to recompile the whole application.
The DICOM archiving system needs continuous updating, maintenance and support. The Joensuu team therefore has created a set of Web based tools to upload client DICOM files to the DICOM database WWW-server; edit items in the image database as well as add DICOM files to it. Thus, the authorized remote client at all times is able to add new data to the database and update the old ones. This patient-focused system today is applied in Saint Raphael- Fréjus, France. For more details, we refer to the Web site of the WWW DICOM Gateway at the University of Joensuu.