In one aspect the invention relates to a method for providing image data of a hollow organ, comprising- applying a first contrast agent to a lumen of the hollow organ, thereby obtaining a contrast agent filling of the lumen,- applying a second contrast agent to a blood vessel system, the blood vessel system supplying a wall of the hollow organ, the second contrast agent having a different absorption spectrum than the first contrast agent,- generating spectrally resolved computed tomography data of an examination area, in particular an examination area of a patient, the examination area comprising the hollow organ,- calculating first image data indicative of a presence of the first contrast agent and second image data indicative of a presence of the second contrast agent by applying a material separation algorithm onto the spectrally resolved computed tomography data,- providing the image data of the hollow organ comprising the first image data and the second image data.
