A method within dynamic molecular imaging comprising dynamically estimating a first parameter (β(x)) and a second parameter (k(x)) of an activity function describing the bio distribution of an administered tracer, is disclosed. More specifically, the method comprises specifying a first target variance (σβ,T(x)) and a second target variance (σβ,T(x)) of the first parameter (β(x)) and the second parameter (k(x)) of the activity function, respectively; initiating an image acquisition; reconstructing the first parameter (β(x)) and the second parameter (k(x)); reconstructing a first associated variance (σβ(x)) and a second associated variance (σk(x)) of the first parameter (β(x)) and the second parameter (k(x)), respectively; and repeating the image acquisition and the reconstructing until the first associated variance (σβ(x)) and the second associated variance (σk(x)) are equal to or less than the first target variance (σβ,T(x)) and the second target variance (σβ,T(x)), respectively, σβ(x)≦σβ,T(x) and σk(x)≦σβ,T(x). The method enables patient-specific adaptive protocols within molecular imaging.