It is described a method for determining and assessing the tissue surrounding an object being inserted into a patient. The method comprises acquiring a first dataset representing a first 3D image of the patient, acquiring a second dataset representing a second 3D image of the blood vessel structure of the patient and acquiring a third dataset representing a 2D image of the patient including the object. The method further comprises recognizing the object within the 2D image, registering two of the three datasets with each other, whereby the object is back-projected in the blood vessel structure, in order to generate a first combined dataset, and registering the first combined dataset with the remaining dataset in order to generate a second combined dataset representing a further image surrounding the object. The method allows for combining diagnostic scanning such as CT, 3D RA and real-time 2D fluoroscopy. Thereby, it is possible to generate an image perpendicular to a catheter tip representing the object being inserted into the patient. Since the 3D-RA displays the lumen and the diagnostic scanning displays soft-tissue, it is possible to assess the tissue at the catheter tip position.