1. A method for assisting a percutaneous intervention, comprising: recording a plurality of 2D x-ray images of an object region of a patient before the intervention with a first resolution at a plurality of different projection angles; reconstructing a first 3D image data of the object region from the 2D x-ray images; performing the percutaneous intervention with an interventional instrument having a needle that is advanced to perform a biopsy and/or puncture in the object region of the patient; recording an ultrasound image containing a part of the object region before and/or during the intervention with a second resolution; registering the ultrasound image with the 3D image data; overlaying the ultrasound image with the 3D image data for guiding the needle, wherein advancement of the needle causes structural distortion in the object region of the patient; generating a new 3D image data configured with a resolution that is lower than the first resolution to estimate a distortion field in the object region of the patient; applying the estimated distortion field to the first 3D image data of the object region to provide a distortion-adjusted 3D image data configured to account for the structural distortion in the object region of the patient; and overlaying the ultrasound image with the distortion-adjusted 3D image data for monitoring further advancement of the needle.