Interactive Direct Volume Rendering of Dural Arteriovenous Fistulae in MR-CISS Data

Dural arteriovenous fistulae are the cause of various somatic diseases. For their analysis DSA is used in medical practice. However, the injection of contrast dye into the vertebral segmental arteries is a time–consuming and highly difficult procedure. Aiming at a reduction of the number of injections required for the detection and exact localization of the pathology, we introduce a new approach which provides meaningful visualization of MR–CISS volumes. Due to the limited spatial resolution of the image data an explicit segmentation of the small vascular structures is extremely difficult. Therefore, we propose a fast sequence of filtering operations and volume growing in order to separate the areas of background, spinal cord and cerebrospinal fluid. Consecutively, we suggest implicit segmentation within these subvolumes. This is achieved by interactively adjusting transfer functions of pre–defined color lookup tables with a few manipulation operations. Thereby, the tiny target vessels contained within the area of cerebrospinal fluid are clearly delineated. Overall, the presented non–invasive approach ensures an optimal spatial understanding of vessel structures in relation to the surrounding anatomy and contributes significantly to reduce the number of injections during DSA examinations.