In current magnetic resonance imaging (MRI), low-field magnets are used to improve the accuracy of the visual data. The cameras are able to detect the handpiece with flashing light emitting diodes (LEDs), defining as such the trajectory and image plane. Dr. Burger stressed the importance of acquiring functional information from different imaging modalities during an intervention. The patient is prepared for the 3D MRI session which equally involves the loading of prior studies. The PMOD software allows to calculate congruent slices in real time through a simple workstation. PMOD is written in JAVA 2 and in Swing. The hardware requirements do not exceed 256 MB of RAM and 10 Mb/s via Ethernet.
The JAVA 2 application is fast and robust enough to allow image fusion with pre-operative 3D MR patient data. During the operation, it is possible that geometrical changes occur. In this case, the fusion is adjusted by means of an intra-operative MR scan, using the PMOD image fusion software. In PET scanning, brain perfusion can be traced by injecting a tracer concentration in the tissue to visualize the time activity curves. Mr. Rudnicki explained how with the PMOD tool a physiological model of the tracer distribution can be designed in order to transform it into a mathematical model. In a next step, the model is fitted to the measured data. For this type of application, the PMOD team uses complex but user-friendly programming languages, namely 3GL, C++ and Java.
Up till now, 19 models have been implemented at the Warsaw University of Technology. The plug-in architecture is compatible with most of the current data formats. JAVA 2 has the advantage of being platform independent and disposes of an object-oriented structure. The installation of the PMOD tool is easy and the Burger/Rudnicki team has already developed a neural network for kinetic modelling. The PMOD software has initially been designed thanks to the help of research grants. Currently, seven international research sites are using the JAVA-based programme as a beta tester since the beginning of 1999. You can find more details and lots of illustrative visual material at the PMOD home page, hosted at the Web site of the Zürich University Hospital.