A method of generating an image of a perfusable structure of an organism, wherein: a fluid is flowing through the perfusable structure; a dose of a traceable agent is present in the fluid, the method comprising: receiving a multitude of samples, wherein each respective particular one of the samples is indicative of a physical quantity representative of a spatial concentration of the traceable agent at a particular one of a plurality of locations in the perfusable structure at a respective time of sampling; and wherein for each specific location of the plurality of locations in the perfusable structure, the method comprises: determining, for each of multiple further ones (114, 116, 118, 120; 402) of the plurality of locations in a specific neighborhood of the specific location, an evolution of the physical quantity, the evolution of the physical quantity representing a development of the physical quantity over time, or a temporal characteristic of the physical quantity, or a temporal pattern of change in a magnitude or other descriptive attribute of the physical quantity, so as to obtain multiple neighborhood evolutions; optionally, determining a specific evolution of the physical quantity at the specific location; determining a similarity representation value dependent on a degree of similarity between the multiple neighborhood evolutions themselves, or on a degree of similarity between the specific evolution and the multiple neighborhood evolutions, and allocating a specific indicator to the specific location in dependence on the similarity representation value for representation of the specific location in the image. a fluid is flowing through the perfusable structure; a dose of a traceable agent is present in the fluid, receiving a multitude of samples, wherein each respective particular one of the samples is indicative of a physical quantity representative of a spatial concentration of the traceable agent at a particular one of a plurality of locations in the perfusable structure at a respective time of sampling; and wherein for each specific location of the plurality of locations in the perfusable structure, the method comprises: determining, for each of multiple further ones (114, 116, 118, 120; 402) of the plurality of locations in a specific neighborhood of the specific location, an evolution of the physical quantity, the evolution of the physical quantity representing a development of the physical quantity over time, or a temporal characteristic of the physical quantity, or a temporal pattern of change in a magnitude or other descriptive attribute of the physical quantity, so as to obtain multiple neighborhood evolutions; optionally, determining a specific evolution of the physical quantity at the specific location; determining a similarity representation value dependent on a degree of similarity between the multiple neighborhood evolutions themselves, or on a degree of similarity between the specific evolution and the multiple neighborhood evolutions, and allocating a specific indicator to the specific location in dependence on the similarity representation value for representation of the specific location in the image. determining, for each of multiple further ones (114, 116, 118, 120; 402) of the plurality of locations in a specific neighborhood of the specific location, an evolution of the physical quantity, the evolution of the physical quantity representing a development of the physical quantity over time, or a temporal characteristic of the physical quantity, or a temporal pattern of change in a magnitude or other descriptive attribute of the physical quantity, so as to obtain multiple neighborhood evolutions; optionally, determining a specific evolution of the physical quantity at the specific location; determining a similarity representation value dependent on a degree of similarity between the multiple neighborhood evolutions themselves, or on a degree of similarity between the specific evolution and the multiple neighborhood evolutions, and allocating a specific indicator to the specific location in dependence on the similarity representation value for representation of the specific location in the image.