A method for quantifying the uptake of at least one radiotracer in a body region of a patient of interest to a positron emission tomography measurement is disclosed. In at least one embodiment of the method, the uptake of the radiotracer in the body region of the patient of interest to the positron emission tomography measurement is quantified taking into account at least one permeability information item relating to the permeability of at least one blood vessel of the patient, in particular in the body region of interest.