Method for quantitative flow analysis of a tree of conduits perfusing an organ from at least two bi-dimensional images, the method comprising the following steps:a) making a 3D reconstruction of at least part of the tree from said at least two bi-dimensional images；b) identifying a segment of interest within the 3D reconstruction；c) making geometric calculations based on the 3D reconstruction；d) receiving from a user input on a model to be considered for the flow analysis and on the location of the segment of interest within such model；e) elaborating the model into a multi-scale functional model of the tree flow；f) scaling the part of the functional model related to the segment of interest using geometrical features of the 3D reconstruction；g) performing quantitative image analysis to correct the functional model to take into account of the status of at least parts of the conduits forming the tree；h) performing quantitative flow analysis based on the functional model so obtained.A corresponding apparatus and computer program are also disclosed.
