Segmentation of large objects from multiple three-dimensional views

The present invention relates to an ultrasound imaging system (10) for inspecting an object (33) in a volume (32). The ultrasound imaging system comprises an ultrasound image acquisition probe (14) for acquiring three-dimensional ultrasound images and providing three-dimensional ultrasound image data, comprising a tracking device (25, 27) for tracking a position of the ultrasound image acquisition probe (14) and providing a viewpoint position (128, 130) of the three-dimensional ultrasound images. By this, an improved initialization and improved co-registration and co-segmentation is enabled by providing a plurality of three-dimensional ultrasound images and their respective viewpoint positions (128, 130), and to conduct a segmentation (80) of the object (33) simultaneously out of the plurality of three-dimensional ultrasound images and taking into account the viewpoint positions (128, 130).