1. A computing system comprising: one or more hardware processors configured to execute software instructions stored in modules, a tangible computer readable medium storing modules configured for execution by the one or more hardware processors, the modules including: a display module configured to display a medical image on a display of the computing system; and an annotation module configured to: provide a user interface on the display in response to completion of a measurement of a lesion on the medical image, the user interface including characteristics associated with the lesion that are selectable by the user, receive indications of one or more of the characteristics that are selected via the user interface, generate an annotation based on the one or more selected characteristics, wherein the user interface or another user interface allows the user to select a particular index of a plurality of indexes to associated with the lesion, wherein association of the lesion with the particular index allows the annotation module to associate the lesion with annotation data of the particular lesion in other exams; and store the generated annotation with an association to the medical image.