A Method for 3D ultrasound image acquisition and registration of a 3D model to a pre-acquired 3D image, comprising the steps of: - providing a pre-acquired 3D image of an object, - displaying said pre-acquired image on a display, - selecting a volume of interest of the object in said pre-acquired image, - when the spatial position of the volume of interest is selected or adjusted as intended: triggering the acquisition of ultrasound images (401, 402) in said volume of interest in order to generate a 3D model of said object in said volume of interest, and - acquiring a plurality of ultrasound images (401, 402) for generating said 3D model by means of said ultrasound probe in the volume of interest while moving the ultrasound probe with respect to said object along the volume of interest, characterized in that the method further comprises the steps of: - checking using a data processing system if the current ultrasound image (401, 402) has at least a pixel in the volume of interest, wherein in case the current image (401, 402) has no pixel in the volume of interest, the current image (401, 402) is discarded by the data processing system, wherein otherwise the current ultrasound image (401, 402) is segmented and compounded by the data processing system into said 3D model to be generated, and - determining using the data processing system a quality measure for the 3D model to be generated upon said acquisition of said ultrasound images (401, 402), wherein said acquisition of said ultrasound images (401, 402) is ended by the data processing system once said quality measure is fulfilled or has reached a pre-defined level, - registering the generated 3D model using the data processing system to the pre-acquired 3D image. - providing a pre-acquired 3D image of an object, - displaying said pre-acquired image on a display, - selecting a volume of interest of the object in said pre-acquired image, - when the spatial position of the volume of interest is selected or adjusted as intended: triggering the acquisition of ultrasound images (401, 402) in said volume of interest in order to generate a 3D model of said object in said volume of interest, and - acquiring a plurality of ultrasound images (401, 402) for generating said 3D model by means of said ultrasound probe in the volume of interest while moving the ultrasound probe with respect to said object along the volume of interest, - checking using a data processing system if the current ultrasound image (401, 402) has at least a pixel in the volume of interest, wherein in case the current image (401, 402) has no pixel in the volume of interest, the current image (401, 402) is discarded by the data processing system, wherein otherwise the current ultrasound image (401, 402) is segmented and compounded by the data processing system into said 3D model to be generated, and - determining using the data processing system a quality measure for the 3D model to be generated upon said acquisition of said ultrasound images (401, 402), wherein said acquisition of said ultrasound images (401, 402) is ended by the data processing system once said quality measure is fulfilled or has reached a pre-defined level, - registering the generated 3D model using the data processing system to the pre-acquired 3D image.