WWW based measurement and visualization of 4D MR cardiac data: a pilot study

This work considers the problem of visualizing the two ventricular chambers from dynamic (4D) MRI cardiac data-which consists of a series of 3D data covering the entire cardiac cycle-in a format that is compatible with the Web, thus appropriate for telemedical applications. The first step consists of the process of segmenting the objects of interest from the raw data. The technique of active surface is employed to effectively enclose the object. The geometric primitive used for the segmentation is a deformable generalized cylinder, defined as a stack of radial curves. The finalized, deformed geometric primitive is presented in VRML 2.0 format. The same process is repeated for all the 3D volumes of the cardiac cycle. The radial displacement is calculated for each point of the active surface and is encoded in color on the VRML vertex, using the RGB color model. Using the VRML 2.0 specifications, morphing is performed showing all cardiac phases in real time. The expert has the ability to view the objects and even interact with them using a simple Internet Browser. Preliminary results with a small number of normal and abnormal cases indicate that very important pathological situations (such as infarction) can be visualized and thus easily diagnosed and localized with the assistance of the proposed technique.