Positron emission tomography is a frontiermedical technology that, in contrast to the othercomputer-assisted technologies providing anatomicalpictures, produces functional images. I argue that PETalso opens up an avenue for shifting from images back toanalysis of measurements. Admittedly, quantification of functionrequires structural constraints. I coined the emerginginterpretational framework quantitative anatomyin an attempt to conceptualize the PET merger betweenmeasuring and imaging, the two competing meansmedicine uses to examine the human body. Anatomyjustifies interpretations that fit the existingknowledge of a larger clinical audience, whilestatistical data (...) possess an unexplored potential tointroduce mathematical rigor in the evaluation offunction, but are still a black box for the majorityof clinicians. This epistemological change is beingcarried out by PET users in action as well as indiscourse. (shrink)