A method for quantitative flow analysis of a fluid flowing in a conduit from a sequence of consecutive image frames of such a conduit, where such image frames are timely separated by a certain time interval, the method comprising:



a) selecting a start image frame and an end image frame from the sequence either automatically or upon user input;
b) determining a centerline of the conduit in the start image frame;
c) determining a centerline of the conduit in the end image frame;
d) selecting a common start point on the centerline of the start image frame and on the centerline of the end image frame either automatically or upon user input;
e) selecting an end point on the centerline of the start image frame;
f) selecting an end point on the centerline of the end image frame;
g) calculating centerline distance between the start point and the end point of the start image frame;
h) calculating centerline distance between the start point and the end point of the end image frame; and
i) calculating a local flow velocity as a function of the centerline distances of g) and h) and a time interval between the start image frame and the end image frame.

A corresponding imaging device and computer program are also disclosed.