The disclosure refers to a method for non-invasively determining a pressure difference in a cardiovascular vessel, comprising providing imaging data indicative of imaging signals detected in a region of interest of a cardiovascular vessel, the region comprising a proximal vessel portion, a distal vessel portion, and a vessel narrowing located between the proximal and the distal vessel； and determining, from the imaging data, a pressure difference between a first location and a second location in the cardiovascular vessel portion, the first location and the second location provided in the proximal and the distal vessel portions, respectively. The determining of the pressure difference comprises, by one or more processors: determining, from the imaging data, a preliminary pressure value indicating pressure difference between the first location and the second location； determining, from the imaging data, time dependent velocity data for blood flow in the first location and the second location； determining, from the time dependent velocity data, a velocity and time dependent pressure value indicating a velocity and time dependent pressure difference between the first location and the second location； and determining the pressure difference for the first location and the second location by combining the preliminary pressure value and the velocity dependent pressure value. Further, a system for non-invasively determining a pressure difference in a cardiovascular vessel is provided.
