1. A system, comprising: a processor configured to receive a first volumetric data set of at least part of an artery, said part comprising a stenosis, wherein the first volumetric data set is generated by a computed tomography scanner; receive at least one two-dimensional data of the stenosis; receive first arterial pressure drop information, said first arterial pressure drop information being an arterial pressure drop around the stenosis; register the first volumetric data set with the at least one two-dimensional data to obtain a second volumetric data set; modify a geometry of the stenosis in the second volumetric data set which generates a third volumetric data set; and estimate a second arterial pressure drop around the geometrically modified stenosis in the third volumetric data set by modifying the first pressure drop based on a change in diameter of the artery or by estimating a proximal and a distal arterial pressure relative to the stenosis after the geometry modification.