Teaser Figure: Left: Brain, visualized using silhouettes, the lesion's spatial depth is displayed using a ring. Center: Combined rendering of brain tissue, skull and fiber tracts using a cutting plane. Right: The virtual path (cyan) from the entry point to the region of interest. The two crossed lines represent the diameter of the virtual cylinder. We present novel interactive methods for the visualization of multimodal volume data as used in neurosurgical therapy planning. These methods allow surgeons to explore multimodal volumes and focus on functional data and lesions. Computer graphics techniques are proposed to create expressive visualizations at interactive frame rates to reduce time-consuming and complex interaction with the medical data. Contributions of our work are the distance-based enhancements of functional data and lesions which allows the surgeon to perceive functional and anatomical structures at once and relate them directly to the intervention. In addition we p...