The present invention relates to an ultrasound imaging system (10) for inspecting an object (97) in a volume (40). The ultrasound imaging system comprises an image processor (36) configured to conduct a segmentation (80) of the object (97) simultaneously out of three-dimensional ultrasound mage data (62) and contrast-enhanced three-dimensional ultrasound image data (60). In particular, this may be done by minimizing an energy tem taking into account both the normal three-dimensional ultrasound image data and the contrast-enhanced three-dimensional image data. By this, the normal three-dimensional ultrasound image data and the contrast-enhanced three-dimensional image data may even be registered during segmentation. Hence, this invention allows a more precise quantification of one organ in two different modalities as well as the registration of two images for simultaneous visualization.