An X-ray imaging method comprises forming 2-dimensional X-ray images of an object to be examined, for example the coronary vascular system of a patient, and reconstruction of a 3-dimensional volume thereof. With a relatively long run length of a scan rotation over substantially 180 of at least 15 sec. and preferably about 20 sec. A sufficient number of images is obtained to perform a more accurate volume reconstruction. This reconstruction method may be combined with existing modelling techniques.